We saw in the earlier posts the similarity between:
Baptornithidae (Hesperornithes) AND (primarily foot-propelled) WEB FOOT diving bird orders, eg. Cormorants (Phalacrocoracidae), Loons (Gaviidae)
AND BETWEEN
Hesperornithidae (Hesperornithes) AND (primarily foot-propelled) LOBE FOOT diving bird orders eg. Grebes (Podicipedidae)
AND BETWEEN
Presbyornithids AND duck, geese and swan (Anseriformes)
Currently these similarities are considered to be due to convergence (evolutionary relay). I am suggesting they are ancestral.
This is something to note:
Cladists decline to identify* the ancestors of these birds (cormorants, loons, grebes, duck, geese and swan). But they are not ruling out that the ancestors may in fact be the ones I just listed. They are just not taking a position on that.
*They decline to identify the ancestors of any and all birds.
Hesperornithes were flightless.
ReplyDeleteDo you have evidence of any flying memebrs?
Harry Seeley, please give us your reference link and copy and paste the material you think is relevant for your assertion.
ReplyDeleteIn fact, you could perhaps do a little research for us on this topic.
For reference:
ReplyDeletehttp://en.wikipedia.org/wiki/Potamornis
"Potamornis is a prehistoric bird genus that dated back to the late Maastrichtian. Its scrappy remains were found in the Lance Formation at Buck Creek, USA, and a single species has been described: Potamornis skutchi.
This was almost certainly a member of the Hesperornithes, the hefty and toothed flightless diving birds of the Mesozoic seas. Its precise relationships are not all to clear; the quadrate bone is unique in some respects but apparently shares more apomorphies with the family Hesperornithidae - the "typical" Hesperornithes - in cladistic analysis[1]. Consequently, it might be considered a fossil hesperornithid with a different feeding specialization. Though it was heavily built like many (flying and flightless) diving birds, it weighed perhaps 1.5 or 2 kg. This raises the possibility that the Hesperornithes not only included flying members (see also Enaliornis), but that their families might have evolved flightlessness independently".
It appears that Hesperornithes included flying birds and secondarily flightless birds.
This supports the ideas I am proposing.
I;m afraid not- weight alone is not evidence of flying capacity.
ReplyDeleteFor reference:
"The Hesperornithidae are obviously derived from flying
birds, and thus, contrary to the sweeping generalizations about
the flightlessness of all hesperornithiform birds (Martin, 1983),
some of their small relatives must have been capable of flight,
as were Ichthyornis and probably Enaliornis (Elzanowski and
Galton, 1991). Unfortunately, nothing can be determined about
the flight ability of Potamornis, because its estimated body
mass (1.5-2.0 kg) falls in the broad overlap between flying and
flightless birds".
http://gspauldino.com/Avianquadrate.pdf
As for Enaliornis, the argument for being able to fly also comes from small weight and pneumaticity of the braincase, except that argument is invalid, as presetned here:
http://books.google.gr/books?id=2MQeh1KCp7sC&pg=PA336&lpg=PA336#v=onepage&q&f=false
IOW, it is as I said: no evidence for flying members exists within Hesperornithiformes. Instead, we have plenty of evidence for flightlessness in the members of the group (Hesperornis, Baptornis etc.).
Of course, it will not be surprising if some evidence for a basal Hesperornithine maintaining flight capability appears at some point, since after all the conventional theory posits that Hesperornithines evolved from flying ancesotrs. But using the group as a link in a lineage from flying animals to flightless animals (with vestigial wings, even) and back to flying animals, is entirely without support. And that's without counting all the other differences of hesperornithines to neornithes.
So perhaps you should do that small research yourself first.
"But using the group as a link in a lineage from flying animals to flightless animals (with vestigial wings, even) and back to flying animals, is entirely without support."
ReplyDeleteI did not say that. I am saying that Hesperornithes flew.
Your comments do not make sense.
Even the posts you quote accept flying Hesperonithes.
Why are you wasting your time and mine?
"weight alone is not evidence of flying capacity."
ReplyDeleteI never said that weight alone is evidence of flying capabilty. Work from what I say and not what you make up.
Stop wasting my time.
The posts I said confirm that there is no compelling evidence of flying members of Hesperornithines at this point. Did you read them? The only indications for capability of flight in Enaliornis are disputed as "invalid", and the assumption of small size allowing flight in Potamornis is inadequate.
ReplyDeleteOn the other hand, we have plenty of evidence that other members of Hesperornithines were flightless, therefore they are out of your lineage.
So your lineage can only use Enaliornis, IF it flew. And we can't say it flew. And that's it. I guess the other subgroups are dead ends, like the conventional theory proposes.
And that's without counting all the other differences of Hesperornithines to modern birds.
From the passage you referenced:
ReplyDelete"The Hesperornithidae are obviously derived from flying birds, and thus, contrary to the sweeping generalizations about the flightlessness of all hesperornithiform birds (Martin, 1983), some of their small relatives must have been capable of flight",
Why are you wasting time with all this mindless objecting?
This is enough on this. Stop wasting my time.
But, as Harry points out, the known "small relatives" are not known to be capable of flight. The flight capabilities of both Enaliornis and Potamornis are disputed. No-one, including Harry, disputes that some of their relatives were capable of flight. But there is nothing to identify whether the LCA of baptornithines and hesperornithines was flightless, or whether flight was lost independently in each group.
ReplyDeleteThis is not "mindless objecting". So far the fossil evidence does not support your claims. Given your repeated insistence that people who object to the dino-to-bird lineage back up their claims with ancestor-descendant lineages, the fact that you cannot establish such a lineage in this case is pretty important.
I like that name - "A Nanny Mouse".
ReplyDeleteAccording to the passage that Harry Seeley gave us it says:
"some of their small relatives must have been capable of flight",".
And other passages refer to flying Hesperornithes.
Do we need to question and re-question every simple, reasonable thing?
The fossil record absolutely supports the idea that some members of Hesperornithes flew. Think about what constitutes evidence. We do not have movies of the period. We have fossils that show the arm structure of a bird.
If this is not sufficient evidence then nothing is ever evidence and we can pack up our bags and go home.
Remember that we are just talking about the interpretations that individuals have made.
You also refer to LCA (Last Common Ancestor). You must know by now that I do not accept cladistic thinking.
But if you want to hold onto the idea that no Hesperornithes flew and that you need more evidence then that is your call. Apply that kind of standard to the imaginary dino to bird lineage and see how far you get.
I am not stating that no hesperornithine flew. I am stating that the evidence that the species we have found could fly is not convincing. The humerus of Enaliornis is unknown, so we do not have fossils that show the arm structure of a bird in this case.
ReplyDeleteHarrison, C.J.O. & Walker, C.A. (1973): Wyleyia: a new bird humerus from the Lower Cretaceous of England. Palaeontology 16(4): 721-728
As for your rejection of the term Last Common Ancestor, this is not dependent on "cladistic thinking". It exists in your ideas too- Unless you wish to propose the idea that each species represents a separate origin of life and then independently traces a path through the various types of animal in a manner similar to the "Scala Naturae", and that speciation and evolutionary radiations do not exist then your idea also uses the concept.
In both cladistics and evolutionary phylogenetics the term is accepted and used- if one group is not directly descended from another (mammals and birds for example), they share a common ancestor. This also occurs within species- your children share a last common ancestor in yourself. Or perhaps you do not exist?
Based on fossils one can then investigate what that last common ancestor was like. In the case of birds and mammals it would not have been warm blooded. In the case of the Baptornithines and the Hesperornithines, which do not appear to be descended from one another we can attempt to do the same. And so far it is not clear what flight capabilities this LCA possessed. It may have been capable of flight- and so flightlessness is an independent acquisition in each family. Or it may not. Currently no statement either way can be made.
"I am stating that the evidence that the species we have found could fly is not convincing."
ReplyDeleteIt is not convincing to you. Okay.
But the world does not revolve around you and what you believe.
I have already said:
If you want to hold onto the idea that no Hesperornithes flew and that you need more evidence then that is your call. Apply that kind of standard to the imaginary dino to bird lineage and see how far you get.
And the idea of common ancestor is tied to cladistics. Just drop the idea of a common ancestor and think in terms of ancestors and descendants. But I am not interested in using up time on this.
Just drop the idea of a common ancestor and think in terms of ancestors and descendants.
"But if you want to hold onto the idea that no Hesperornithes flew and that you need more evidence then that is your call. Apply that kind of standard to the imaginary dino to bird lineage and see how far you get".
ReplyDeleteIt is interesting that you should say that. A few points in that regard:
Consider Potamornis. You are eager to view it as a flying member of Hesperornithines- yet, it poses for you, more or less, the very same problem that Mahakala supposedly poses for the dino to bird theory. It lived in the Maastrichtian, quite later than other, flightless Hesperornithines.
So, in order to accept it as evidence, you will have to adopt the reasoning you previously disputed, and say it is more basal based on its characteristics, not on when it lived.
Also, if a flying Hesperornithine is found and displays less derived characteristics, where will those characteristics point to? The dino-to-bird theory says they will show similaritiy with derived birds, so the wing will have the structure of the bird wing, the feet will have the toe orientation and function of perching bird feet, etc.
Your theory must show a transition from a dormeosaurid group (Microraptor and Rahonavis are the only ones you are able to use ATM), so the basal Hesperornithine must have feet resembling the sickle-clawed feet of dromeosaurs, or wings with bone structure similar to flying dromeosaurids (and not the more derived bird form).
Now THAT would be a compelling evidence for your lineage. But no such evidence exists.
On the other hand, If basal Hesperornithines looked like birds, then we must conclude that dromeosaurs turned to birds FIRST and THEN those birds turned to Hesperornithine birds.
And guess what, that's supporting the conventional theory, save a few details.
look at the wing structure of Hesperornis. Besides the small size, does it look like a dromeosaur limb or a bird limb?
Harry Seeley, you have overlooked that the lineages I am proposing include Enantiornithes.
ReplyDeletePlease rewrite your objection taking that into account.
The fact that you overlooked that, means that you are just mindlessly objecting without actually considering seriously what I am proposing.
I have said this before and I say it again:
You just mindlessly throw up any objection you can and see if something sticks.
That is why I do not take your objections seriously and do not post all your comments. You are wasting my time.
"It is not convincing to you. Okay.
ReplyDeleteBut the world does not revolve around you and what you believe."
Indeed not, but as already stated the evidence is equivocal. It would be best not to make statements about the parallel loss of flight in the two hesperornithine families. I am not "holding on to the idea that no hesperornithine flew" I am saying that most of the ones we know could not, and it has not been conclusively demonstrated in the two where it is considered possible.
"Apply that kind of standard to the imaginary dino to bird lineage and see how far you get."
I have. In this case it is convincing, as there is significantly more evidence. Birds are maniraptorans. Maniraptorans are coelurosaurians. Coelurosaurians are dinosaurs. The evidence comes from studying the morphology at a much deeper level than you have been.
"And the idea of common ancestor is tied to cladistics. Just drop the idea of a common ancestor and think in terms of ancestors and descendants. But I am not interested in using up time on this."
If you think that the concept of the LCA is tied to cladistics then you are very much mistaken. It has been part of evolution since Darwin's time. Humans share a common ancestor with chimps- we are both that animal's descendants.
The LCA is tied up with the concept of ancestors and descendants, as is indicated in the words it stands for "Last Common Ancestor". If two species are descended from a third then that third species is the LCA of its two descendants.
How do you propose dropping this idea is useful unless you consider each species to have a completely independent history back to the origin of all life?
People do not realize that I welcome all serious objections and criticisms. I am putting these ideas forward as a serious, scientific alternative to the dino to bird theory. But I am not interested in wasting my time with mindless objections.
ReplyDeleteAlso I know that people will argue the smallest point till the cows come home.
I have better things to do than waste my time on that.
Nonny Mouse - I am not interested in straightening you out about LCA and cladistics. I would then be in the position of having to straighten people out ONE BY ONE and I have better things to do.
ReplyDeleteI have told you twice to drop the LCA talk and just use ancestors and descendants. If you cannot do that, then there is no basis for discussion.
I have addressed the flying Hesperonithes question.
As I have said people can argue any point till the cows come home.
That means nothing.
Once again we see that people who have been programmed with cladistics no longer have the ability to see beyond it.
ReplyDeleteThey loose the ability to see things as they actually are - ancestors and descendants.
I have told others that they need to just drop the cladistoc thinking.
But they keep trying to shoehorn any idea into their cladistic straight-jacket.
They are so programmed that they do not even realize what the world actually looks like.
Just as an exercise, drop the cladistic thinking and look at the world fresh, as it actually is.
Nonny Mouse posted:
ReplyDelete"In both cladistics and evolutionary phylogenetics the term is accepted and used- .."
When I read that, I thought it was an odd phrase.
What does "evolutionary phylogenetics" mean? Is that "evolutionary systematics"?
It is this sort of slight change that makes me suspicious, having seen this so many times.
Remember :
http://www.kheper.net/evolution/systematics/evolutionary.htm
"Also, unlike Cladistics, with it's reliance on a hypothetical Most Recent Common Ancestor that is never actually described or discovered (a missing link that is always missing), Evolutionary systematics gives illustrations of the actual evolution of one species or higher taxon into another."
The main point of this thread is the bolded part:
ReplyDelete"Cladists decline to identify* the ancestors of these birds (cormorants, loons, grebes, duck, geese and swan). But they are not ruling out that the ancestors may in fact be the ones I just listed. They are just not talking a position on that".
An Anonymous poster confirmed this point earlier:
"Because of how cladograms are drawn they will appear on separate branches even if they're ancestral to each other".
So if opinion changes, that for example some bird lines evolved directly from hesperornithes, people will say that that was always a possibility, that that was always possible and that the cladograms did not rule it out.
*They decline to identify the ancestors of all birds.
"I am not interested in straightening you out about LCA and cladistics. I would then be in the position of having to straighten people out ONE BY ONE and I have better things to do."
ReplyDeleteI think you had better, because everyone, regardless of whether they accept cladistics or not uses and understands the term. I shall continue to do so until you can explain why I should not. Are Baptornis and Hesperornis descended from a single species at any point in their evolutionary history? (Perhaps something like Enaliornis? Perhaps a pterosaur? Perhaps a dromaeosaur?) If they are, then whatever that organism was it was the
Last Common Ancestor of those two taxa. You can reject cladistics and that statement is true.
"I have told you twice to drop the LCA talk and just use ancestors and descendants. If you cannot do that, then there is no basis for discussion."
Why should I do that when I'm specifically discussing the last ancestor shared by two taxonomic groups (the LCA), and am not discussing anything prior to that? Surely by "ancestors and descendants" I am not being precise enough in my words, and am creating greater confusion? Nobody doubts that the Hesperornithiformes had a flying ancestor. The question is where was flight lost? Before the split between the Hesperornis and Baptornis (their LCA)? Perhaps before the split between Enaliornis and the more derived species (the LCA of the whole group)? Or independently in each family after these events? There is no "cladistic thinking" involved in this.
"When I read that, I thought it was an odd phrase.
What does "evolutionary phylogenetics" mean? Is that "evolutionary systematics"?
It is this sort of slight change that makes me suspicious, having seen this so many times."
Indeed. It was supposed to be "evolutionary systematics". I misspoke. There is no need to be suspicious. Evolutionary systematics does make claims about which groups evolved into which other groups, and explicitly uses paraphyletic groupings to illustrate this. It too talks about the last common ancestor of two taxa, and in some cases can attempt to identify it.
"So if opinion changes, that for example some bird lines evolved directly from hesperornithes, people will say that that was always a possibility, that that was always possible and that the cladograms did not rule it out."
Actually the cladograms as currently reconstructed do rule it out. Hesperornithines are monophyletic. Neornithines are monophyletic. No member of the Neornithines is closer to the Hesperornithines than to any other member of the Neornithines. Furthermore Hesperornithines does not contain the Neornithines (or indeed any members of this group). The cladograms currently explicitly rule out the idea that grebes, loons and cormorants belong in the Hesperornithines, and separately acquired their neornithine characters as your ideas would require.
"They decline to identify the ancestors of all birds."
Because, as you have been told multiple times it is impossible to do so. Most potential ancestors are either too late in time, living at the same time as more birdlike species, have unique specialisations that mean they cannot be ancestral (Hesperornithiformes and their tiny arms), and in every case are widely separated by gaps in the geological record where we have no fossils and cannot be sure if species X was ancestral or another species living 300 miles away but which was never fossilised because conditions were not right. All we can say is which species are closer to which other species.
"Indeed. It was supposed to be "evolutionary systematics". I misspoke. There is no need to be suspicious. Evolutionary systematics does make claims about which groups evolved into which other groups, and explicitly uses paraphyletic groupings to illustrate this. It too talks about the last common ancestor of two taxa, and in some cases can attempt to identify it.
ReplyDeletePlease support your assertion (the part in bold) with a link and copy and paste what you think is the relevant material.
You posted:
ReplyDelete"Hesperornithiformes and their tiny arms"
Please support your assertion with a link and copy and paste what you think is the relevant material.
You posted:
ReplyDelete"and separately acquired their neornithine characters as your ideas would require."
What characters are those?
"Harry Seeley, you have overlooked that the lineages I am proposing include Enantiornithes.
ReplyDeletePlease rewrite your objection taking that into account.
The fact that you overlooked that, means that you are just mindlessly objecting without actually considering seriously what I am proposing.
I have said this before and I say it again:
You just mindlessly throw up any objection you can and see if something sticks.
That is why I do not take your objections seriously and do not post all your comments. You are wasting my time".
Actually, I was confused there. I have considered Enantiornithines to be unrelated to the subgroups in your particular lineage. I might have been confused, but that is the only way your direct transition idea about aquatic birds makes any sense IMO. if you consider Enantiornithines as a link from dromeosaurs to more modern birds, with some dromeosaur-like traits (in a lesser degree, like ie. claws on their wings), then what is the point in using the Hesperornithes subgroup in the first place? You are going with assumed ancestors anyway. You have no evidence for a flying dromeosaur with aquatic adaptations, but you assume it's there in the lineage. We have some evidence for aquatic adaptation in Enantiornithines, so why include Hesperornithines in the line? Just to find something about webbed feet and diving? And then ignore the HUGE problem of flightlessness, by assuming more undiscovered flying members?
And if you think that some aquatic features did not exist from the start on the lineage, and need Hesperornithines to stick them in, then how do you justify the pterosaur beginnings of your lineage? What similarities do you consider as stable throughout the lineages? And again, why couldn't those features have appeared in modern bird groups, again making Hesperornithines redundant?
And of course, you still need a flying Herperornithine (Hesperornithidae most certainly were NOT able to fly, and we have no firm evidence on any of the other families).
Now, let me rephrase my previous question to reflect your lineage: Would a basal flying Hesperornithine display traits similar to Enantiornithines? For example, would it have claws on its wings?
Also, what is your problem with a LCA? Take your theory, for example. You consider most dromeosaurid groups to be "secondarily flightless", and also you consider Hesperornis, Baptornis etc. to be secondarily flightless members of Hesperornithines. Now, since those members "developed" within your perspective lineage, don't they also have a common ancestor within your lineage? Doesn't say, Utahraptor and Microraptor share a common ancestor, within your lineage? Doesn't Hesperornis and some undefined flying Hesperornithine also share a common ancestor? If not, what does "secondarily flightless" mean?
BTW, as for why you are not posting my comments, save it. It is evident that you do it when you cannot respond to me.
The main point of this thread is the bolded part:
ReplyDelete"Cladists decline to identify* the ancestors of these birds (cormorants, loons, grebes, duck, geese and swan). But they are not ruling out that the ancestors may in fact be the ones I just listed. They are just not talking a position on that".
If that's the main point, then it's simply false. No scientist claims that Hesperornithines "may" be the ancestors of "cormorants, loons, grebes, duck, geese and swan". Do you have any in mind?
If you do, then please post your references etc.
Not being able to identify a direct ancestor does not mean anything goes.
You posted:
ReplyDelete"You consider most dromeosaurid groups to be "secondarily flightless","
I definitely do not consider most dromeosaurid groups to be "secondarily flightless". SOME became flightless.
Where do you get these ideas? Do you actually read what I have posted. Did you see the set of entries I just posted, that show lineages by habitat. All contain Dromaeosaurids, only one is a flightless lineage.
Harry Seeley, your post is so confused that I wonder if you have even read the posts I have posted. You make it all so confusing and complicated when it is quite simple.
ReplyDeleteFirst you overlook Enantiornithes and then you come up with the most convoluted understanding of what I am proposing.
Do you understand the idea that one taxon can evolve into another?
Or has cladistics so warped your mind that you have lost sight of that basic idea?
""and separately acquired their neornithine characters as your ideas would require."
ReplyDeleteWhat characters are those?"
Surely you should be familiar with the characters that unite the Neornithes? After all, if you are proposing that the characters are parallelisms you should be familiar with the characters?
Be that as it may, http://evolutionwiki.org/wiki/Neornithes lists the following shared derived characters of Neornithes:
a) Premaxilla/maxilla fused
b) Maxilla greatly reduced and primarily restricted to the palatal region
c) Mandibular symphysis fused
d) Dentary and surangular fused
e) Teeth absent
f) Humeral facet of coracoid does not extend laterally beyond the scapular facet of the coracoid
g) Scapular humeral facet is oriented laterally or craniolaterally
h) Humeral facet of coracoid separated slightly or completely from the scapular facet
i) Humeral head large
j) Sulcus for transverse humeral ligament distinct
k) Deltopectoral crest of humerus inflected cranially
l) Pneumotricipital fossa pierced by a pneumatic foramen
Mayr & Clarke 2003 list the following characters:
(1) maxilla without teeth; (91) pelvis with 15–16 vertebrae ankylozed in synsacrum; (100) distal end of tibiotarsus with ossified pons upratendineus; and (107) tarsometatarsus with canalis interosseus distalis
They also find the following characters to support the Neognathae:
(20) vomers mediolaterally narrow; (21) vomers forming a midline, narrow, and dorsoventrally high lamella; (22) os palatinum and os pterygoideum separated; (29) tubae auditivae paired and close to/adjacent on cranial midline or single anterior opening; (32) fronto-parietal suture closed; (61) pygostyle, corpus not perforated at caudoventral end; (79) humerus with distinct fossa musculi brachialis; (81)humerus with well-developed sulcus scapulotricipitalis; (94) pelvis with foramen ilioischiadicum caudally closed;nand (103) tarsometatarsus, hypotarsus with well-developed
cristae/sulci.
Mayr G, Clarke J. Cladistics The deep divergences of neornithine birds : a phylogenetic analysis of morphological characters. Cladistics. 2003;19:527-553.
Livezey & Zusi list the following:
Condylus occipitalis, collum condyli occipi-
talis present, condylus comparatively prominent, and variably subpedicellate or (sub)umbelliform with basis having (often slightly) smaller diameter than condylus proprius, aspect subglobular.
Recessus columellae, shallow, recessus distinct, but fenestra vestibuli
and fenestra cochleae only slightly deep to margo recessi, recessus tympanicus caudalis (if present) with internum exposed
Os metacarpale alulare (I, primus), size
relative to that of os metacarpale II less than one-third of latter
Phalanges digitorum I–III manus, phalanges unguales, length relatively short
Phalanges digitorum I–III manus, phalanges unguales, forma et situs proximodistalis tuberculorum flexoriae present, curvature distinct and tuberculae flexoriae moderately distal
Phalanges digitorum I–III manus, phalanges unguales, bases phalanges, cotylae articulares, margines dorsales, relatively smooth
Ala (pars) preacetabularis ilii, facies dorsalis, margo medialis et crista iliaca dorsalis, bilateral compression, medial proximity, elevation, and synostosis between cranial vertebrae sacrales, cristae spinosae cristae do not articulate, remain straight, but are not elevated and do not approach medially.
Corpus tibiotarsi, facies cranialis, sulcus extensorius, present, presenting continuum of proximal extents, widths, and delimitation.
Digitus II (secundus) pedis, phalanges digiti (including digitus ungualis), present, four
Livezy & Zusi, 2006 Phylogeny of Neornithines, Bulletin of Carnegie Museum of Natural History, 37 : 1-544 2006 pp1-544.
Can you provide a similar level of detail to support your assertions that these characters must be convergent in every group of modern birds that you independently derive from pterosaur ancestors?
You had said:
ReplyDelete"The cladograms currently explicitly rule out the idea that grebes, loons and cormorants belong in the Hesperornithines, and separately acquired their neornithine characters as your ideas would require."
I asked you:
"What characters are those?"
You did not answer my question.
I am not the only one who has proposed a link
ReplyDeletebetween Hesperonithes and modern birds.
http://www.jstor.org/pss/2413412
"A cladistic analysis of the skeletons of loons (Gaviidae), grebes (Podicipedidae), and the Cretaceous diving birds, Hesperornisand Baptornis, supports the hypothesis that they form a monophyletic group (here called the Gaviomorphae) within the class Aves. Two lineages within the gaviomorphs can be delineated: (1) loons + grebes, and (2) Hesperornis + Baptornis. The Early Cretaceous Enaliornis and the Late Cretaceous Neogaeornis are related to the second lineage; the Late Cretaceous Lonchodytes, often placed near loons, is apparently not a gaviomorph but perhaps a charadriiform. Skeletal evidence also suggests that penguins (Spheniscidae) are the sister-group of the Gaviomorphae. Arguments that similarities of gaviomorph taxa represent convergence are not well founded. First, morphological differences among taxa do not constitute valid evidence against their monophyly, as many previous workers have argued. Second, in no case has anyone supporting convergence presented a corroborated alternative phylogenetic hypothesis. A close relationship among gaviomorphs, penguins, and apparently also the Procellariiformes and Pelecaniformes implies that a lineage of aquatic birds was established very early in avian history, presumably in the Early Cretaceous or Late Jurassic." (Joel Cracraft 1982)
"I asked you:
ReplyDelete"What characters are those?"
You did not answer my question."
I just gave you a long list of characters that neornithes possess. You claim that some neornithes "developed" from the Hesperornithiformes. And that some did not. Therefore for every separate origin of a neornithine group those characters must be re-acquired each time. In Ratites, in owls, in "landbirds" in "shorebirds" in the two diving birds that you derive from separate families within the Hesperornithiformes, and in whatever other divisions you choose to make. It very clearly answers your question.
"I definitely do not consider most dromeosaurid groups to be "secondarily flightless". SOME became flightless."
But most dromaeosaur species are flightless. The only ones that appear to have had any flying abilities (no matter how poor) are Microraptor, Rahonavis, and possibly Anchiornis (I don't know how much work has been done on its aerodynamic properties. Not enough I suspect).
"All contain Dromaeosaurids, only one is a flightless lineage."
They all contain the same two dromaeosaurs for which we have evidence of any flying capability. If Microraptor is ancestral to the landbirds it cannot also be ancestral to grebes, as they are descended from a completely different group of pterosaurs. Other than the troodontid-owl link (which you have been informed elsewhere does not stand up) you have not specified which dromaeosaurs are descended from which pterosaurs, and are ancestral to which birds.
""Hesperornithiformes and their tiny arms" Please copy and paste..."
Look at all the images of them that you've been posting so far. Do any of them have robust forelimbs? No, they do not. And in the two species that are the best candidates for having any flight abilities the data is lacking- they almost certainly had bigger arms than their more derived relatives, but were they capable of supporting them in the air? Were they of a comparable size to modern flying cormorants? Or perhaps closer to the flightless Galapagos species, which has small stunted wings, but nothing to compare to the almost complete loss of arms in Baptornis and Hesperornis. So far the evidence is completely absent. The humerus of Enaliornis is unknown. (I have not been able to read the description of Potamornis I'm afraid, so I have no idea which elements are preserved and which are not. One would think there would be more definitive statements about its flight capabilities were the arms preserved.
And Cracraft has since changed his mind as more data has accrued
ReplyDeletehttp://www.tc.umn.edu/~barke042/pdfs/Cracraft.et.al04.pdf
A Nonny Mouse, you say a lot and skirt my question.
ReplyDeleteYou posted:
"The cladograms currently explicitly rule out the idea that grebes, loons and cormorants belong in the Hesperornithines, and separately acquired their neornithine characters as your ideas would require."
I asked about your specific assertion about Hesperornithes - what characters?
I am tired of your hide and seek posts.
Answer my question please. Else what is the point of your posting here if you cannot support the things you say.
Also support your assertions about Hesperornithes arms.
ReplyDeleteWith a link(s) and copy and paste the material you think is relevant.
A Nonny Mouse posted:
ReplyDelete"And Cracraft has since changed his mind as more data has accrued
http://www.tc.umn.edu/~barke042/pdfs/Cracraft.et.al04.pdf"
A Nonny Mouse you are half way there. You have given a link.
Now copy and paste the material that you think is relevant.
"I asked about your specific assertion about Hesperornithes - what characters?
ReplyDeleteI am tired of your hide and seek posts.
Answer my question please. Else what is the point of your posting here if you cannot support the things you say."
I was referring to characters present in grebes, loons, cormorants and all the other neornithine groups, and which are lacking in the Hesperornithiformes. The ones I listed from several different papers.
Those characters I listed are not present in Hesperornithiformes. They are present in neornithines. They must therefore have evolved independently in grebes and cormorants, loons, owls, "landbirds", Galloanserae, Ratites (including or excluding tinamous?), "shorebirds", and "seabirds" if your idea is correct, as the common ancestor of all these groups did not possess any of them.
"Also support your assertions about Hesperornithes arms.
With a link(s) and copy and paste the material you think is relevant."
No. The information is freely available. Read the articles you have cited yourself. Look at the images you have posted yourself. Are you denying that Hesperornis has tiny arms? What is your evidence against an assertion that has been made since Marsh described the specimens? Link to, copy and paste the parts you think are relevant.
We have already dealt with the fact that the humerus is unknown in Enaliornis. It may be robust, it may not. Currently it can tell us nothing. I have not seen the paper describing Potamornis- perhaps you have and can quote their description of its arms- if indeed they were preserved?
""And Cracraft has since changed his mind as more data has accrued"
A Nonny Mouse you are half way there. You have given a link.
Now copy and paste the material that you think is relevant."
The whole paper is relevant. At no point does Cracraft support a closer relationship between grebes and loons and the hesperornithines, than between hesperornithines and any other modern bird group.
I'm sorry if you find my posts confusing. I'll try to make them as simple as possible. I am only try to pose some simple questions, wich I think you should be asking yourself in the first place.
ReplyDeleteFirst of all, you say:
"I definitely do not consider most dromeosaurid groups to be "secondarily flightless". SOME became flightless.
Where do you get these ideas? Do you actually read what I have posted. Did you see the set of entries I just posted, that show lineages by habitat. All contain Dromaeosaurids, only one is a flightless lineage".
I do not think you comprehend the consequences of what you propose. The fact that you use only a part of dromeosaurid groups for your lineages, does not mean that the others don't exist and you needn't account for them.
Here is a list of dromeosaurid groups, from Wikipedia:
Family Dromaeosauridae
Dromaeosauroides
Luanchuanraptor
Mahakala
Pamparaptor[59]
Ornithodesmus
Tianyuraptor
Variraptor (=Pyroraptor?)
Subfamily Microraptorinae
Graciliraptor
Hesperonychus
Microraptor (=Cryptovolans?)
Sinornithosaurus
Subfamily Unenlagiinae[60]
Austroraptor[61]
Buitreraptor
Neuquenraptor
Rahonavis
Shanag?
Unenlagia
Unquillosaurus
Node Eudromaeosauria[9]
Subfamily Dromaeosaurinae
Subfamily Saurornitholestinae
Subfamily Velociraptorinae
So you have five subfamilies, each with its own members, plus a number of unassigned members.
From those subfamilies, you only use two, in each of which there is only one (1) member that has full or partial flying ability.
So it is safe to say that you use SOME members of dromeosaurids, and that you consider MOST other members to be secondarily flightless. At least that's if you work with what we have from the fossil record. You could claim that there were many more flying members in the groups, that we haven't found for some reason, but then you are faced with a distinct lack of evidence for that assumption.
Now, where did those secondarily flightless members come from? They would have to have diverged from flying members at some point. Therefore, that means that they would have to share a common ancestor with flying members within your lineage.
THAT is the concept of LCA.
Otherwise, those flightless dromeosaurids would have to have a completely separate descent, unrelated to your pterosaur--> bird one, and that is not what you propose.
It is the same with flightless Hesperornithines. It doesn't matter if they diverged from flying Hesperornithines, or earlier in your Enantiornithines stage of developement. SINCE they diverged to become "secondarily" flightless, then they have had to have a LCA with members of your lineage from enantiornithines to hesperornitnhines to modern birds.
There is no cladistic reasoning involved. There is only reasoning involved.
Now, back to my question. If we discover a basal flying Herserornithine, would that have to share similarities with Enantiornithines (which were its supposed ancestors)? Like say, claws in the wings or something like that?
What is your prediction? Theories are supposed to make some predictions.
"A Nonny Mouse you are half way there. You have given a link.
ReplyDeleteNow copy and paste the material that you think is relevant".
Just look at table 27.1, for crying out loud. Do you seriously expect others to extract part of a .pdf file as an image, upload it and embed it on your blog, because you're too bored to check it yourself? Seriously?
BTW, Hesperornis wing:
ReplyDeletehttp://www.uua.cn/Aves/UploadFiles/200706/20070601105750607.jpg
http://upload.wikimedia.org/wikipedia/commons/8/85/Hesperornis_regalis_%281%29.jpg
A cpoy-pasted relevant picture is worth a thoushand copy-pasted relevant words.
"BTW, Hesperornis wing:
ReplyDeletehttp://www.uua.cn/Aves/UploadFiles/200706/20070601105750607.jpg
http://upload.wikimedia.org/wikipedia/commons/8/85/Hesperornis_regalis_%281%29.jpg
A cpoy-pasted relevant picture is worth a thoushand copy-pasted relevant words."
Thank you. I am familiar with them.
They show clearly the short arms.
See also my post
http://pterosaurnet.blogspot.com/2011/10/aquatic-birds.html
which shows another example.
Same short arms.
A Nonny Mouse posted:
ReplyDelete"Indeed. It was supposed to be "evolutionary systematics". I misspoke. There is no need to be suspicious. Evolutionary systematics does make claims about which groups evolved into which other groups, and explicitly uses paraphyletic groupings to illustrate this. It too talks about the last common ancestor of two taxa, and in some cases can attempt to identify it."
Please support your assertion (the part in bold) with a link and copy and paste what you think is the relevant material
"A Nonny Mouse, I did a search on the article.
ReplyDeleteThere is no reference to Hesperonis or Hesperornithes. When you have some support for your assertion please let us know."
So you did not read it, like I told you to. Your standard of scholarship leaves much to be desired. If you wish to be taken seriously you must make yourself familiar with the fossil record- skimming papers here and there, and copy-pasting sections of wikipedia is not good enough. You do want to be taken seriously don't you?
Look for the discussion of grebes, loons and cormorants. Look at where they are placed in the various classifcation schemes he discusses. He does not claim they are outside of the neornithines. Nor does he place hesperornithiformes within neornithines (which would be an alternative way of rescuing this hypothesis). In fact he makes no mention of this hypothesis at all. Clear evidence that he does not regard it as being well supported. If he still did would you net expect him to mention it?
"I take any "change of heart" with a big grain of salt."
Even when the as more evidence arrives it demonstrates that someone was wrong, as appears to be the case? This is the whole point of doing good science. To attempt to disprove your hypothesis. Use your idea to make predictions. Test those predictions by looking for observations or experimental results that would disprove it. The most important question you can ask yourself is "how would you know if you were wrong". Frankly I would distrust any scientist who had never changed their mind about any of their ideas when presented with contradictory data. many of course will hold on to their ideas in the face of this evidence (it is human nature after all) but not all will.
What evidence would cause you to reject your ideas? How would you know if you were wrong?
"Thank you. I am familiar with them.
They show clearly the short arms."
Then why did you keep asking me to post references to them? We both accept they have short arms. Why must I provide copy-pasted references for things that neither of us dispute?
Harry Seeley posted:
ReplyDelete"Now, back to my question. If we discover a basal flying Herserornithine, would that have to share similarities with Enantiornithines (which were its supposed ancestors)? Like say, claws in the wings or something like that?
What is your prediction? Theories are supposed to make some predictions."
Here is what I have posted so far in this work in progress:
Pterosaur (Ctenochasmatoidea) eg. Pterodactylus -->
Dromaeosaurid subgroup (eg. Microraptor, Rahonavis) -->
An Enantiornithes aquatic subgroup -->
Baptornithidae (Hesperornithes) -->
(primarily foot-propelled) WEB FOOT diving bird orders, eg. Cormorants (Phalacrocoracidae), Loons (Gaviidae).
AND
Pterosaur (Ctenochasmatoidea) eg. Pterodactylus -->
Dromaeosaurid subgroup (eg. Microraptor, Rahonavis) -->
An Enantiornithes aquatic subgroup -->
Hesperornithidae (Hesperornithes) -->
(primarily foot-propelled) LOBE FOOT diving bird orders eg. Grebes (Podicipedidae).
--------------------------------
So certainly Hesperornithes subgroups share characters with the Enantiornithes aquatic subgroups which I propose to be their ancestor.
Care to work with me on analyzing that in more detail?
Earlier interchange:
ReplyDelete""And Cracraft has since changed his mind as more data has accrued"
"A Nonny Mouse you are half way there. You have given a link.
Now copy and paste the material that you think is relevant."
"The whole paper is relevant. At no point does Cracraft support a closer relationship between grebes and loons and the hesperornithines, than between hesperornithines and any other modern bird group."
A Nonny Mouse, I did a search on the article.
There is no reference to Hesperonis or Hesperornithes. When you have some support for your assertion please let us know.
By the way, on those occasions when someone in the field has the courage to present a new idea, they get so much flack (and they want to keep their job) that they "recant" their heresy. That is life.
I take any "change of heart" with a big grain of salt.
""It too talks about the last common ancestor of two taxa, and in some cases can attempt to identify it."
ReplyDeletePlease support your assertion (the part in bold) with a link and copy and paste what you think is the relevant material"
Since you are too lazy to read the sentence in the Wikipedia article about evolutionary systematics that you have already cited elsewhere:
"The two approaches differ in the use of the word monophyletic. For evolutionary systematicists, monophyletic means only that a group derives from a single common ancestor included in the group, whereas for cladists it also means that the group includes all species descended from that group. The term holophyletic has been proposed for the latter meaning."
http://en.wikipedia.org/wiki/Evolutionary_systematics
Now, about all those characters and their implications for your theory. How do you account for the fact that your theory is massively unparsimonious?
A Nonny Mouse posted:
ReplyDelete"So you did not read it, like I told you to"
I had read it, months ago, when I posted about it. In response to your post I did the search on it for hesperornis and hesperornithes to save time.
If you submit sarcasm and insults like this I will stop posting your comments.
In fact work with this idea - any comment that you submit that contains insults or sarcasm will not be posted.
If you do not like that condition then don't post. Your call.
"Thank you. I am familiar with them.
ReplyDeleteThey show clearly the short arms."
"Then why did you keep asking me to post references to them? We both accept they have short arms. Why must I provide copy-pasted references for things that neither of us dispute?"
So we both agree that it had short arms.
That is a far cry from flightless.
"So we both agree that it had short arms.
ReplyDeleteThat is a far cry from flightless."
Except in this case they clearly were flightless, as every site you have linked to demonstrates.
"“The scapula is long and slender, and has no acromial process. The clavicles are separate, but meet on the median line, as in some very young existing birds. The coracoids are short, and much expanded where they join the sternum. The latter has no distinct manubrium, and is entirely without a keel. The wings were represented by the humerus only, which is long and slender, and without any trace of articulation at its distal end. Its position was close to the ribs, and it was probably nearly or quite concealed beneath the integuments, as in Apteryx. This rendered the rudimentary wings of no possible service in flight or swimming.”"
O.C. Marsh 1877
http://www.oceansofkansas.com/Hesperornis.html
Are you seriously proposing that Hesperornis flew?
"So we both agree that it had short arms.
ReplyDeleteThat is a far cry from flightless."
Except in this case they clearly were flightless, as every site you have linked to demonstrates.
We both agree BY LOOKING AT IT that it had short arms. We both agree on that.
Did you want to retract your agreement?
People can do what I did. Get out your ruler and measure the length of the arms on the fossil. Notice the hand as well.
ReplyDeleteSee how long that is. (Put it in perspective by comparing it with the length of the legs for example.)
Then see how long the arms are on existing flying birds with short wings.)
You will see that birds can fly with that length of arm.
What may throw people off at first is that bird wings seem very long. That is because we are looking at the feathers which extend out well beyond the bones.
Take a look for yourself.
This is an interesting subject and I did the research on it many months ago.
http://oceansofkansas.com/Hesperornis/martin60.jpg
Also:
ReplyDelete"So certainly Hesperornithes subgroups share characters with the Enantiornithes aquatic subgroups which I propose to be their ancestor.
Care to work with me on analyzing that in more detail"?
Thank you. That is what I'm trying to do. Now, what kind of similarities would indicate a direct ancestor-descendant relationship, rather than a close relative group? What evidence in morphology would make us say "it's not just that there is a close morphological relation, implying that those groups had a recent common ancestor, but surely group A was the very ancestor of group B"?
I mentioned claws on the wings. Do you think that would help?
"The two approaches differ in the use of the word monophyletic. For evolutionary systematicists, monophyletic means only that a group derives from a single common ancestor included in the group, whereas for cladists it also means that the group includes all species descended from that group. The term holophyletic has been proposed for the latter meaning."
ReplyDeleteA "single common ancestor" is the opposite of the LCA concept.
And in fact this wiki entry about "single common ancestor" does not describe evolutionary systematics correctly.
The ancestor is not in the group. The group evolved FROM the ancestor.
The wiki entry was written by a cladist who still does not understand evolutionary systematics. That is a REAL problem.
People do not understand evolutionary systematics. But they imagine that they understand it.
ReplyDeleteTHAT IS A REAL PROBLEM.
Harry Seeley posted:
ReplyDelete"Thank you. That is what I'm trying to do. Now, what kind of similarities would indicate a direct ancestor-descendant relationship, rather than a close relative group? What evidence in morphology would make us say "it's not just that there is a close morphological relation, implying that those groups had a recent common ancestor, but surely group A was the very ancestor of group B"?"
You keep talking about a recent common ancestor.
How many times do I have to tell you to not try to shoehorn this into cladistic terms.
When you are prepared to look at this in terms of ancestor descendant relationships we can talk.
How on earth do you "measure" the length of the arms in that picture and compare them to the length of the hindlimbs in that picture?
ReplyDeleteAre you seriously suggesting they are comparable?
Here's another picture from that link you provided:
http://oceansofkansas.com/Hesperornis/UNSM20030-Baptornis.jpg
And here's a comparison with a bird skeleton.
http://academic.emporia.edu/sievertl/verstruc/birdbody2.JPG
See the radius and ulna? The carpometacarpals? Are you SERIOUSLY suggesting they are comparable?
Here's a loon stretching its wings:
http://www.wildlifewindow.com/images/istock_flying_common_loon.jpg
http://thumbs.dreamstime.com/thumblarge_532/12823281330W8kd0.jpg
And a loon skeleton:
http://farm1.static.flickr.com/236/3264188052_a87e88778f.jpg
COmpare the size of those wings to your baptornis picture.
Also, from the VERY TEXT accompanying the picture you posted on the link:
"Somewhat more primitive and about half the size of Hesperornis, the 1 m (~3 ft 4 in) Baptornis had LOST the ability to fly (IF it's ancestors had flown?), and possessed only VESTIGIAL wings (upper limbs). However, unlike Hesperornis, all of the wing bones were still present, although GREATLY REDUCED in size".
[Some caps mine]
And here's abetter picture of the upper limb of Hesperornis- bear in mind that, unlike Baptornis, it just has the humerus!!!
http://oceansofkansas.com/Hesperornis/vp2069j.jpg
Accompanying text:
"LEFT: FHSM VP-2293 - Two views of the right humerus - Note that the wing (upper limb) in Hesperornis was very reduced in size and probably non-functional".
So, under the light of all that, I believe it's safe to say:
If you think that Hesperornis or Baptornis could actually fly, then PROVIDE A LINK AND COPY AND PASTE THE RELEVANT MATERIAL.
Just apply to yourself the standards you want others to follow.
"You keep talking about a recent common ancestor.
ReplyDeleteHow many times do I have to tell you to not try to shoehorn this into cladistic terms.
When you are prepared to look at this in terms of ancestor descendant relationships we can talk".
You did not comment my previous point about your theory including common ancestors, so I figured you had understood. Apparently I was wrong.
Let me repeat:
First of all, you say:
"I definitely do not consider most dromeosaurid groups to be "secondarily flightless". SOME became flightless.
Where do you get these ideas? Do you actually read what I have posted. Did you see the set of entries I just posted, that show lineages by habitat. All contain Dromaeosaurids, only one is a flightless lineage".
I do not think you comprehend the consequences of what you propose. The fact that you use only a part of dromeosaurid groups for your lineages, does not mean that the others don't exist and you needn't account for them.
Here is a list of dromeosaurid groups, from Wikipedia:
Family Dromaeosauridae
Dromaeosauroides
Luanchuanraptor
Mahakala
Pamparaptor[59]
Ornithodesmus
Tianyuraptor
Variraptor (=Pyroraptor?)
Subfamily Microraptorinae
Graciliraptor
Hesperonychus
Microraptor (=Cryptovolans?)
Sinornithosaurus
Subfamily Unenlagiinae[60]
Austroraptor[61]
Buitreraptor
Neuquenraptor
Rahonavis
Shanag?
Unenlagia
Unquillosaurus
Node Eudromaeosauria[9]
Subfamily Dromaeosaurinae
Subfamily Saurornitholestinae
Subfamily Velociraptorinae
So you have five subfamilies, each with its own members, plus a number of unassigned members.
From those subfamilies, you only use two, in each of which there is only one (1) member that has full or partial flying ability.
So it is safe to say that you use SOME members of dromeosaurids, and that you consider MOST other members to be secondarily flightless. At least that's if you work with what we have from the fossil record. You could claim that there were many more flying members in the groups, that we haven't found for some reason, but then you are faced with a distinct lack of evidence for that assumption.
Now, where did those secondarily flightless members come from? They would have to have diverged from flying members at some point. Therefore, that means that they would have to share a common ancestor with flying members within your lineage.
THAT is the concept of LCA.
Otherwise, those flightless dromeosaurids would have to have a completely separate descent, unrelated to your pterosaur--> bird one, and that is not what you propose.
It is the same with flightless Hesperornithines. It doesn't matter if they diverged from flying Hesperornithines, or earlier in your Enantiornithines stage of developement. SINCE they diverged to become "secondarily" flightless, then they have had to have a LCA with members of your lineage from enantiornithines to hesperornitnhines to modern birds.
There is no cladistic reasoning involved. There is only reasoning involved.
People cannot see the misconceptions in cladistics. There is no point in trying to explain it - people will refuse to get it. I know from experience that is the case.
ReplyDeleteThat being the case, the only path left is to tell people to not use it.
Just use ancestor descendant relationships.
OK. What is the ancestor-descendant relationship between Utahraptor and Hesperornis?
ReplyDelete"If you think that Hesperornis or Baptornis could actually fly, then PROVIDE A LINK AND COPY AND PASTE THE RELEVANT MATERIAL."
ReplyDeleteThe links you provided demonstrate the feasibility of flight.
What length would they need to be in your opinion to make them feasible for flight? How short of that are the fossil bones?
2 inches too short? 6 inches too short? 1 foot too short? 2 feet too short?
How much too short are those bones in your opinion?
"How on earth do you "measure" the length of the arms in that picture and compare them to the length of the hindlimbs in that picture?
ReplyDeleteAre you seriously suggesting they are comparable?"
This is the last of your posts that contain your use of the word serious or seriously that I will post.
If I was not serious I would not be posting.
Your post is simply insulting and intended to be insulting.
Concerning the idea of comparing it to the length of the leg - that is such a simple and reasonable idea that I see that you are just stuck for something to criticizer. I did not say that they were the same length (but they are close) but just to compare them.
This is what I am getting at. You are simply desperate to find something to misunderstand and criticize.
From this point I will be even more discerning about which of your submissions to post.
You are wasting my time.
"It is the same with flightless Hesperornithines. It doesn't matter if they diverged from flying Hesperornithines, or earlier in your Enantiornithines stage of developement. SINCE they diverged to become "secondarily" flightless, then they have had to have a LCA with members of your lineage from enantiornithines to hesperornitnhines to modern birds."
ReplyDeleteWhen you present your ideas in ancestor descendant terms I will respond.
Anonymous posted:
ReplyDelete"OK. What is the ancestor-descendant relationship between Utahraptor and Hesperornis?"
The link between Dromaeosaurids (eg. Utahraptor*) and Hesperornithes is the Enantiornithes.
This is the second person who has overlooked the Enantiornithes.
AND I MENTIONED THAT ALREADY.
Anonymous please include a made up name in your next post. Thanks.
*It would take more analysis to see if Utahraptor specifically, was on the line to Hesperornithes.
"If you think that Hesperornis or Baptornis could actually fly, then PROVIDE A LINK AND COPY AND PASTE THE RELEVANT MATERIAL."
ReplyDelete"The links you provided demonstrate the feasibility of flight.
What length would they need to be in your opinion to make them feasible for flight? How short of that are the fossil bones?
2 inches too short? 6 inches too short? 1 foot too short? 2 feet too short?
How much too short are those bones in your opinion?"
Anyone can contribute on this question.
Please do.
Harry Seely posted:
ReplyDelete"And here's a better picture of the upper limb of Hesperornis- bear in mind that, unlike Baptornis, it just has the humerus!!!
http://oceansofkansas.com/Hesperornis/vp2069j.jpg"
Are you thinking that the creature only had a humerus or that they did not discover the other parts of the arm?
"A "single common ancestor" is the opposite of the LCA concept."
ReplyDeleteNo it is not. The LCA is the single common ancestor- it is the most recent species that is ancestral to the members of a group.
"And in fact this wiki entry about "single common ancestor" does not describe evolutionary systematics correctly.
The ancestor is not in the group. The group evolved FROM the ancestor."
Wrong. The monophyletic group includes the ancestor. It does not necessarily include all the descendants, and is therefore paraphyletic (whether or not people approve of paraphyletic groups is another matter). That ancestor may be a member of another group, which would then be paraphyletic. But Evolutionary Systematics does accept and use the concept of the LCA.
"You keep talking about a recent common ancestor.
How many times do I have to tell you to not try to shoehorn this into cladistic terms.
When you are prepared to look at this in terms of ancestor descendant relationships we can talk."
If Hesperornis is not directly ancestral to a modern diving bird, but merely a close cousin, then it shares a common ancestor with those birds. That is what Harry Seeley is getting at. Both it, and the modern birds it is most closely related to in your scheme are descended from a third species. Which would be the "last common ancestor" for these two taxa.
Your children are not ancestral to each other, but share a common ancestor.
"You will see that birds can fly with that length of arm.
What may throw people off at first is that bird wings seem very long. That is because we are looking at the feathers which extend out well beyond the bones.
Take a look for yourself. "
No, what is throwing people off is the absence of a keel on the breastbone to anchor the muscles and the vast difference in thickness of the loon's wing and the Baptornis wing. The entire wing in Baptornis is smaller than the shin. It has more robust ribs than its arms. The musculature required for flight is absent.
Compare the loon skeleton with the Hesperornis skeleton
http://farm1.static.flickr.com/236/3264188052_a87e88778f.jpg
http://oceansofkansas.com/Hesperornis/vp2069j.jpg
We see the same problem amplified even further. In this case the humerus is thinner than the sternal ribs, and the whole pectoral girdle is even further reduced.
"Are you thinking that the creature only had a humerus or that they did not discover the other parts of the arm?"
ReplyDeleteIt only has a humerus, as the description from Marsh 1877 that I already posted states:
“The scapula is long and slender, and has no acromial process. The clavicles are separate, but meet on the median line, as in some very young existing birds. The coracoids are short, and much expanded where they join the sternum. The latter has no distinct manubrium, and is entirely without a keel. The wings were represented by the humerus only, which is long and slender, and without any trace of articulation at its distal end. Its position was close to the ribs, and it was probably nearly or quite concealed beneath the integuments, as in Apteryx. This rendered the rudimentary wings of no possible service in flight or swimming.”
Flightlessness has been accepted and demonstrated since the discovery of the bird.
A Nonny Mouse posted:
ReplyDelete"But Evolutionary Systematics does accept and use the concept of the LCA".
You do not understand the philosophical differences between cladistics and evolutionary systematics.
There is no point in discussing this.
Just use ancestor descendant relationships.
"The links you provided demonstrate the feasibility of flight"
ReplyDeleteHow does saying "Baptornis had LOST the ability to fly (IF it's ancestors had flown?)" and "possessed only VESTIGIAL wings (upper limbs" demonstrate the feasibility of flight?
How does saying "Note that the wing (upper limb) in Hesperornis was very reduced in size and probably non-functional". suggest the feasibility of flight?
How can you say something like that, and just expect it to be accepted?
I have provided links and material that clearly and unequivocally, in plain English and word for word, say Hesperornis and Baptornis did NOT have the ability to fly. and you say that they say it *could* fly? In what possible reading can such a contradictory conclusion be assumed?
Also:
"This is the last of your posts that contain your use of the word serious or seriously that I will post.
If I was not serious I would not be posting".
Explain to me how one has to accept that, when a source says that Hesperornis could NOT fly, we should take that as meaning it WAS feasible for it to fly. If you can explain that to me, in a coherent and sound way, I will not dispute you on that part and apologize.
In the meantime, I have done precisely what you asked: Provided links and quoted the relevant material. SO, before I go on about how flying works, and about generating lift, and about the anatomy of the bird wing and its corresponding bones, and basically whether THIS animal
http://images.nationalgeographic.com/wpf/media-live/photos/000/005/cache/hesperornis_572_600x450.jpg
Had the wingspan and power to lift itself off the ground and fly (!!!),
You need to do the same you have demanded from me:
If you think Hesperornis or Baptornis could fly, then please present a link and copy and paste the relevant material.
Or admit you have no such links or material.
Either way, when you have done one or the other, we can examine whether that animal could fly.
Apply to yourself the standards you demand from others.
"Are you thinking that the creature only had a humerus or that they did not discover the other parts of the arm?"
ReplyDeleteIt only has a humerus, as the description from Marsh 1877 that I already posted states.."
That is of course crazy.
A creature with just a humerus? What happened to the rest of the arm?
Have there been any other finds that just include the humerus?
The most parsimonious explanation is that the rest of the arm was not found.
Think about all the other creatures of that type that had all the arm parts.
Are we taking the findings of over 100 years ago as the final word on this?
People do not use their ordinary common sense.
From Marsh:
ReplyDelete“The scapula is long and slender, and has no acromial process. The clavicles are separate, but meet on the median line, as in some very young existing birds.
as in some very young existing birds.
Clearly the fossil they found was of a young Hesperornis. That explains the findings - along with the idea that they did not find the rest of the arm parts.
People - you are allowed to think. To think for yourself when you have the evidence right in front of you.
I am getting tired of using up time showing that members of Hesperornithes could fly.
ReplyDeleteAs I have said - people can argue any point till the cows come home. That means nothing.
"When you present your ideas in ancestor descendant terms I will respond".
ReplyDeleteI AM talking about ancestors and descendants. Forget cladistics and all that. A secondary flightless dromeosaurid had an ancestor, right? Since it was SECONDARILY flightless, then at some point its ancestor was able to fly, right?
Now, was that flying ancestor within one of the members in the lineage leading to enantiornithes? If not, then what lineage was it and which groups were in that lineage? Did they also come from pterosaurs? DIFFERENT groups of pterosaurs?
And so on.
So you see, unless you argue that those (and so many other) parallel groups were separate from the very beginning of life, you actually need a common ancestor at some point. Cladistics has nothing to do with it.
I said:
ReplyDelete"The links you provided demonstrate the feasibility of flight"
The links you provided (that I was referring to) were pictures of fossils.
I was not referring to the interpretations that others made.
Did you not realize that? But you probably did realize that but chose to spin it.
You spin things like that.
I am getting tired of discussing this with you.
Here is a link you provided:
http://images.nationalgeographic.com/wpf/media-live/photos/000/005/cache/hesperornis_572_600x450.jpg
That is a picture drawn by someone. That is not a fossil. That is OF COURSE just an interpretation based on other people's interpretations.
We can see the evidence OURSELVES.
You are allowed to think for yourself.
I will stop this now. You are wasting my time.
Here is the problem underlying all this.
ReplyDeletePeople here refuse to think for themselves.
Their teacher has told them something and that is it. And you accept only what the consensus believes.
You do not allow yourself to have an original idea. Or to have an idea that is contrary to the CURRENT consensus OPINION.
You spend ALL your time adamantly showing that the current opinion is correct. You do that right up to the moment when the consensus changes.
Then you prove that the new consensus opinion is correct. Just as adamantly.
Think for yourself. Give it a try - you may come to enjoy it.
.
"If you think that Hesperornis or Baptornis could actually fly, then PROVIDE A LINK AND COPY AND PASTE THE RELEVANT MATERIAL."
ReplyDelete"The links you provided demonstrate the feasibility of flight.
What length would they need to be in your opinion to make them feasible for flight? How short of that are the fossil bones?
2 inches too short? 6 inches too short? 1 foot too short? 2 feet too short?
How much too short are those bones in your opinion?"
Anyone can contribute on this question.
Please do.
Harry Seeley posted:
ReplyDelete"So you see, unless you argue that those (and so many other) parallel groups were separate from the very beginning of life, you actually need a common ancestor at some point. Cladistics has nothing to do with it."
Just work from the lineages I laid out in the most recent posts. Look at them.
Ask questions about them.
I will be happy to discuss them.
I want to repeat this until someone actually answers:
ReplyDelete"If you think that Hesperornis or Baptornis could actually fly, then PROVIDE A LINK AND COPY AND PASTE THE RELEVANT MATERIAL."
"The links you provided demonstrate the feasibility of flight.
What length would they need to be in your opinion to make them feasible for flight? How short of that are the fossil bones?
2 inches too short? 6 inches too short? 1 foot too short? 2 feet too short?
How much too short are those bones in your opinion?"
Anyone can contribute on this question.
Please do.
"You do not understand the philosophical differences between cladistics and evolutionary systematics.
ReplyDeleteThere is no point in discussing this.
Just use ancestor descendant relationships."
Actually I do. Both explicitly accept the idea of common ancestors- indeed the very name evolutionary systematics implies the existence of common ancestors from which families, genera and orders arise. How can I talk about ancestor-descendant relationships when I am discussing how two taxa which are not descended from each other are related? You seem to have missed the point that your children are not descended from each other, but share a common ancestor in yourself. The same is true of species, and is accepted in evolutionary systematics.
"That is of course crazy.
A creature with just a humerus? What happened to the rest of the arm?"
It was lost through evolutionary time as the animal did not fly, and mutations that reduced the arms were not penalised as they would be in a flying bird. Flying is extremely expensive to maintain, and is one of the first things lost as soon as birds no longer need to (for example when they colonise islands). Modern kiwis have arms that are about as reduced as those of Baptornis. Many birds have more robust arm-bones than Baptornis, and they are incapable of flight. Several species of moa have no arm bones at all. Humans have been born with no lower arms.
"Are we taking the findings of over 100 years ago as the final word on this?"
No. Many other discoveries have been made since. No arm bones other than the humerus have been found. Marsh's observation still holds: "The wings were represented by the humerus only, which is long and slender, and without any trace of articulation at its distal end"
That last sentence is important. As is the observation that the humerus is long and slender the animal totally lacked the musculature needed to support itself in the air.
"Clearly the fossil they found was of a young Hesperornis. That explains the findings - along with the idea that they did not find the rest of the arm parts."
No it does not. He is comparing Hesperornis to hatchling birds. How big are you proposing Hesperornis got if a six foot specimen is still a "young bird"? How do you explain the other Hesperornis fossils that also lack the humerus and any trace of a keel on the breastbone? Are they all juveniles? Do they show any other juvenile characters such as unfused long bones? If they do why doesn't Marsh mention this fact?
Marsh directly examined several specimens. The follow-up research that backs up his findings also looked at his specimens, and much more subsequent material. How many specimens have you examined? Of Hesperornis? Or of any fossil species you have mentioned on this blog?
A Nonny Mouse, as much as I enjoy discussing the issue of flying Hesperornithes I am going to move on.
ReplyDeleteThis could go on forever.
Whatever I say you will have something to respond with.
And as far as cladistics goes, it would take too long for me to straighten out your thinking and even then it would turn into another UNENDING argument.
I know that you think you know the issues involved but you do not.
A Nonny Mouse said...
ReplyDeleteIt is not the length that is the issue, but the robustness relative to the length. There is no keel on the breastbone. The entire shoulder girdle is greatly reduced. There is no way it could support itself in the air.
If you think it could you'd better support your thesis. How many species of birds have such reduced arms, relative to the size of the body, but are still capable of flight? Compare the robustness of the forelimbs to the hindlimbs in Baptornis Then do the same for the loon skeleton. Do you see the difference? If anything the wings in the loon are bigger and more robust than its legs. This is very obviously not the case in the hesperornithines under discussion.
The length was the issue earlier. Right?
ReplyDeleteNow it looks like people are seeing that the wings were long enough for flight.
When you come to see I was right about something, you do not acknowledge it. You just bluster on about other things.
There is really no point continuing with this.
"The length was the issue earlier. Right?"
ReplyDeleteNo. I did not just refer to the length. You did. You did not mention how slender the bone is relative to its length- which is the important factor.
"Now it looks like people are seeing that the wings were long enough for flight."
No. The wings are neither long enough NOR robust enough for flight. For one thing there's no hand on Hesperornis- so it could not have flown at all, given how bird wings operate.
"When you come to see I was right about something, you do not acknowledge it."
I do not acknowledge that you are right- because you are NOT right. You are wrong abot the arms of hesperornithines and their flight capabilities, as is amply demonstrated by the fossils. You are wrong about the concept of LCAs and their applicability to evolutionary systematics.
You are going to have to explain exactly why you think you are right. And do so without reference to "cladistic programming" and the rest. How can you explain how two species that are not descended from one another are related together without reference to their common ancestor?
And how many specimens have you examined that leads you to disagree with everyone who has ever published on the hesperornithines? What are your credentials?
No. People are telling you they were not long enough flight.
ReplyDeleteA Nonny Mouse posted:
ReplyDelete"The wings are neither long enough.."
Then here is a question for you:
What length would they need to be in your opinion to make them feasible for flight? How short of that are the fossil bones?
2 inches too short? 6 inches too short? 1 foot too short? 2 feet too short?
How much too short are those bones in your opinion?
Not sure what you mean Abe Froman by:
ReplyDelete"People are telling you they were not long enough flight."
"Harry Seeley posted:
ReplyDelete"So you see, unless you argue that those (and so many other) parallel groups were separate from the very beginning of life, you actually need a common ancestor at some point. Cladistics has nothing to do with it."
Just work from the lineages I laid out in the most recent posts. Look at them.
Ask questions about them.
I will be happy to discuss them".
You seem to do quite the opposite. It appears that you do not want to talk about the fact that a secondary flightless dromeosaurid will have to have a common ancesotr at some point with a flying dromeosaurid.
WHy is that?
It depends on the size of the bird. Hesperornis is six feet long, and heavily built. You'd probably have to have something with arms more robust than a bustard (and they're pretty poor fliers). The arms are thin weedy things.
ReplyDeleteWikipedia states this about the Kori Bustard-
"The male Kori Bustard is 120 to 150 cm (3.9 to 4.9 ft), stands 71–120 cm (2.33–3.9 ft) tall and have a wingspan about 230 to 275 cm (7.5 to 9.02 ft). On average male birds weigh about 10.9–16 kg"
So I'd be expecting to see something with arms nearly a metre long.
Hesperornis has a humerus 15.2cm long, and 0.7cm wide. Ichthyornis, which was very much smaller, and could fly had a humerus 5.8cm long and 1.3cm wide. Far more robust than that of Hesperornis
So 2 feet too short sounds about right, and that's probably an underestimate.
This image shows how tiny the arms are in comparison to the legs.
http://upload.wikimedia.org/wikipedia/commons/8/85/Hesperornis_regalis_%281%29.jpg
Are you still contending that something with arms that thin, spindly and poorly muscled could fly?
I see that there are a number of species of Hesperornis.
ReplyDeleteIs it the case that all of them had only the humerus and all were missing the other parts of the arm?
Hesperonis species
http://en.wikipedia.org/wiki/Hesperornis
H. regalis Marsh, 1872 (type)
H. crassipes (Marsh, 1876) [originally Lestornis]
H. gracilis Marsh, 1876
H. altus (Marsh, 1893) [originally Coniornis]
H. montana Schufeldt, 1915
H. rossicus Nesov & Yarkov, 1993
H. bairdi Martin & Lim, 2002
H. chowi Martin & Lim, 2002
H. macdonaldi Martin & Lim, 2002
H. mengeli Martin & Lim, 2002
Harry Seeley posted:
ReplyDelete"a secondary flightless dromeosaurid will have to have a common ancesotr at some point with a flying dromeosaurid."
The secondarily flightless dromaeosaurids were simply that set of dromaeodaurids that settled on the land and over time lost their flying characteristics.
There is no need for the cladistic idea of last common ancestor.
"This image shows how tiny the arms are in comparison to the legs.
ReplyDeletehttp://upload.wikimedia.org/wikipedia/commons/8/85/Hesperornis_regalis_%281%29.jpg"
The image only includes the humerus. If the rest of the arm were found the arm would be quite long. Certainly long enough for flight.
What rest of the arm?
ReplyDeleteThe rest of the arm - the missing parts of the arm. All they found was the humerus in the one species.
ReplyDeleteTake a look at this:
Hesperonis:
http://oceansofkansas.com/Hesperornis/usnmhesa.jpg
and this:
Baptornis
http://oceansofkansas.com/Hesperornis/martin60.jpg
Notice that the humerus in both are near identical. In the Baptornis the rest of the arm was found.
In the Hesperornis the rest of the arm was not found.
Unless someone wants to make the case that these two members of Hesperornithes were different - with only one just having a humerus and the other having the humerus and the rest of the arm. Sure that could be. But the more parsimonious explanation is that the rest of the arm parts were not found. Like a number of other bones of the creature were not found.
Can you or anyone answer my question about other Hesperornis species? Did all Hesperornis species have a humerus and no other arm parts. Are there fossils supporting that idea?
"The image only includes the humerus. If the rest of the arm were found the arm would be quite long. Certainly long enough for flight."
ReplyDeleteNo it would not be. The humerus in Hesperornis is 15cm long and less than a centimetre wide. In birds the humerus is the longest bone in the wing. You would need a forearm three feet long- utterly different to that seen in any other bird. You still cannot avoid the fact that the arm bone is too slim to anchor the muscles required. Compare it to the same bone in the flying Ichthyornis. They are totally different.
"But the more parsimonious explanation is that the rest of the arm parts were not found. Like a number of other bones of the creature were not found."
Marsh states there is no point for articulation of the forearm on the humerus.
We have many fossils of Hesperornis. We have all the bones. The rest of the arm bones are not there. But it was found in Baptornis. The two species show different levels of reduction of the forearm.
This is a much better picture of Hesperornis' humerus:
http://oceansofkansas.com/Hesperornis/vp22293b.jpg
It appears larger on my screen than it would be in real life. The animal was six feet long.
"Is it the case that all of them had only the humerus and all were missing the other parts of the arm?"
Go and read the papers Wikipedia refers to. The full reference is on the page. Find out and tell us. The descriptions of the species in those papers will tell you.
"The secondarily flightless dromaeosaurids were simply that set of dromaeodaurids that settled on the land and over time lost their flying characteristics.
There is no need for the cladistic idea of last common ancestor."
But these specific dromaeosaurs are not ancestral to any modern flying birds. How do you propose to describe their relationships with these other animals without referring to the fact that they share a common ancestor with them?
"Is it the case that all of them had only the humerus and all were missing the other parts of the arm?"
ReplyDelete"Go and read the papers Wikipedia refers to. The full reference is on the page. Find out and tell us. The descriptions of the species in those papers will tell you."
There is something quite strange here. People here talk as if they knew this topic. They are so confident. But in fact they are simply expressing their opinions.
When it comes to the facts and the evidence they tell me to go and come back and tell them.
For some reason it is important to people here to believe that Hesperornis could not fly.
And your whole argument seems to be based on one bone in one fossil from over 100 years ago that is labelled as a humerus.
It makes no sense.
Especially since the creature in all other aspects is the mirror image of modern diving birds*.
If I ever offered up evidence of that questionable nature nobody here would accept it for a moment.
It has been already said that "some of their small relatives must have been capable of flight,".
Creatures within Hesperornithes could fly.
There is not really not much point in arguing this point.
We are arguing about one bone in one fossil!! It is necessary for me to ask again - what is your alternative?
And on your side you have NOTHING.
Please tell us your suggestion of the ancestor of loons, grebes etc. And we can put it under the microscope and see how it stands up.
Till then you really cannot expect me to take you seriously.
*We have not talked about this, but you have to be claiming that Nature evolved a modern bird - identical to the Hesperornithes COMPLETELY INDEPENDENTLY.
And this evolutionary relay in your thinking applies to both Hesperornis and Baptornis.
When we step back and look at the bigger picture we have to shake our heads and wonder why we are even talking about this.
It is obvious that the most parsimonious explanation is that modern diving birds developed from the almost identical primitive birds in the Hesperornithes. Your position is based on magic. When a simple answer is available.
"The secondarily flightless dromaeosaurids were simply that set of dromaeodaurids that settled on the land and over time lost their flying characteristics.
ReplyDeleteThere is no need for the cladistic idea of last common ancestor."
"But these specific dromaeosaurs are not ancestral to any modern flying birds. How do you propose to describe their relationships with these other animals without referring to the fact that they share a common ancestor with them?"
A subgroup of dromaeosaurids settled on the land.
At that point, the ones that had settled on the ground developed into a set of modern flightless birds AND the rest of the flying dromaeosaurids developed into a set of modern flying birds.
That is what I am suggesting.
What problem (if any) do you have with what I have suggested?
I have been trying to figure out what the disagreement concerning Hesperornis/Hesperornithes is.
ReplyDeleteIs it that Hesperonis regalis could not fly but other members of Hesperornis might have been able to fly?
Is it that the specific Hesperornis genus could not fly but there is an acceptance that other members of Hesperornithes could fly?
What is the disagreement exactly.
"A subgroup of dromaeosaurids settled on the land.
ReplyDeleteAt that point, the ones that had settled on the ground developed into a set of modern flightless birds AND the rest of the flying dromaeosaurids developed into a set of modern flying birds.
That is what I am suggesting.
What problem (if any) do you have with what I have suggested"?
Where did that "subgroup" come from?
If it was a population withing the original group of flying dromeosaurids, then it must have shared common ancestry with it.
If it wasn't, where did it come from? A different subgroup of pterosaurs? And where did THAT come from?
If you extrapolate that logic, you must claim that those groups and their ancestors were distinct from the beginning of life itself.
This is, what, the fourth time someone told you that? Let's see if you finally decide to acknowledge it.
"I have been trying to figure out what the disagreement concerning Hesperornis/Hesperornithes is.
ReplyDeleteIs it that Hesperonis regalis could not fly but other members of Hesperornis might have been able to fly?
Is it that the specific Hesperornis genus could not fly but there is an acceptance that other members of Hesperornithes could fly?
What is the disagreement exactly".
The disagreement is that Hesperornis could NOT fly, Baptornis could NOT fly, and we have no EIVDENCE of any flying Hesperornithes so far. We POSTULATE that some basal members could fly, based on having (guess what?) A COMMON ANCESTOR with flying birds. When that ancestor lived, and whether flight ability was lost within Hesperornithes or sooner, is not yet known.
Simple as that.
Now, where is your evidence that Hesperornis could fly?
please provide references and copy and paste the relevant material. Enough running around.
"There is something quite strange here. People here talk as if they knew this topic. They are so confident. But in fact they are simply expressing their opinions."
ReplyDeleteNo. It is simply that I cannot be bothered to check the descriptions of every fossil referred to each species of Hesperornis The type, and first described species of the genus lack forearms altogether. Baptornis have greatly reduced wings. It is not "opinion" that they were incapable of flight it is a stone cold fact.
"For some reason it is important to people here to believe that Hesperornis could not fly."
It seems important to you that it could. All the evidence is against this position. It is important for us to accept that Hesperornis could not fly because that is what the fossils conclusively show. If we do not accept this then we may as well not bother looking at them and just make things up.
"And your whole argument seems to be based on one bone in one fossil from over 100 years ago that is labelled as a humerus."
No. It is based on multiple fossils collected overa span of over 100 years. It is based on the fact that the bone labelled a humerus is found in exactly the same position all other humeri in all other animals are found. It is further based on the massive reduction of the shoulder girdle associated with this humerus.
How many Hesperornis fossils have you looked at?
"We have not talked about this, but you have to be claiming that Nature evolved a modern bird - identical to the Hesperornithes COMPLETELY INDEPENDENTLY.
And this evolutionary relay in your thinking applies to both Hesperornis and Baptornis."
But grebes, loons and cormorants share features with each other and other birds that are not seen in the hesperornithiformes. The features I listed above. So they are not "completely identical". The convergent evolution in this case only applies to adaptations for diving. And these adaptations (along with others unrelated to ecology) shared between the hesperornithidae and baptonithidae would have been present in the ancestor that gave rise to these two families.
"It is obvious that the most parsimonious explanation is that modern diving birds developed from the almost identical primitive birds in the Hesperornithes. Your position is based on magic. When a simple answer is available."
No it is not. How is it "magic" to think that birds that dive will have similar adaptations to diving (there are diving ducks, which also have some of these adaptations too, but are not descended from hesperornithiformes in your scheme) but not "magic" to think that all those characters unrelated to ecology evolved independently in each bird lineage- and that's just the modern birds, when you look at the characters that identify maniraptorans, avialae, neognathans, and the various other subdivisions of "birds" that you think all have independent ancestry from pterosaurs, then you've clearly given up on any pretence of applying parsimony.
"I have been trying to figure out what the disagreement concerning Hesperornis/Hesperornithes is."
ReplyDeleteYou have claimed that, based on its humerus Hesperornis could fly. Everyone else thinks this is silly.
There is no acceptance that any member of the Heperornithiformes could fly. The arms of Enaliornis are unknown, but it may have been able to fly. Potamornis is equivocal- if it is a member of the hesperornithidae, and could fly then the two families evolved their flightlessness independently. These are the only two genera within the whole group for which there is any indication that flight was possible. If it was possible in any other species do you not think the various websites would mention this?
"A subgroup of dromaeosaurids settled on the land.
ReplyDeleteAt that point, the ones that had settled on the ground developed into a set of modern flightless birds AND the rest of the flying dromaeosaurids developed into a set of modern flying birds.
That is what I am suggesting.
What problem (if any) do you have with what I have suggested?"
Firstly, you have multiple origins for the dromaeosaurs. Some are descended from Azdarchids, some from Ctenochasmids, some from Ornithocheirids, and so on. Not all of these groups have given rise to modern flightless birds. Many species of flightless birds that do occur are nested deep within these taxa. If you want to break taxa up into flying and non-flying members and have them descend from different dromaeosaur ancestors then your problems with parsimony are exponentially increased.
You are claiming that some dromaeosaurs are more closely related to some pterosaurs than they are to other pterosaurs. Which makes dromaeosaurs (and birds) polyphyletic, and not a natural group, and thus rejected by evolutionary systematics, which does use the concept of the LCA despite your protestations to the contrary. The name "dromaeosaur" and "bird" have as much utility in describing a group as "worm" does. You would be best to stop using both, and refer to the species you mean.
Secondly are all flightless dromaeosaurs ancestral to modern flightless birds? Or only some of them? If they evolve into ornithomimids (which then evolve into ratites) then the ones that lived after the appearance of the ornithomimids cannot be ancestral to the ratites, as their earlier relatives have already evolved into this group. They can, however, share a common ancestor with them.
Notably however the troodontid with asymmetric ears is flghtless. So it cannot be ancestral to owls unless you propose that owls lost and regained the power of flight. Angain, it could share a common ancestor, despite not being an ancestor itself. (I shall merely point out that troodontid and owl ear asymmetry is not comparable. The asymmetry in owls is not seen in the skull, but only soft tissue, takes a variety of forms, and is not seen in a large number of species- the genus Bubo contains species with and without ear asymmetry.)
"Creatures within Hesperornithes could fly.
ReplyDeleteThere is not really not much point in arguing this point."
I do not dispute that some members of the hesperornithiformes could fly- they must have done because the group is descended from a flying ancestor. But no member of this group has been demonstrated to actually fly, and for most their flightlessness is very much assured.
"We are arguing about one bone in one fossil!! It is necessary for me to ask again - what is your alternative?"
Actually its not just one bone. It is the whole arm and shoulder girdle in every specimen of Hesperornis and Baptornis which preserves them.
An alternative is that all modern birds are a natural group that is more closely related to Ichthyornis than to the hesperornithiformes.
A further alternative would be that your polyphyletic grouping of "birds" is correct, but that the hesperornithines we have found are not ancestral to grebes, loons, etc, but do share a common ancestor, which has not been found.
"Please tell us your suggestion of the ancestor of loons, grebes etc. And we can put it under the microscope and see how it stands up."
I do not have one. I do not know what it was. There are, I believe, a couple of fossils from the Tertiary which have been assigned to these various groups. But we can't be sure if they're ancestral, or merely close relatives of the modern species. But I can confidently rule out Hesperornis because it possesses none of the characters seen in modern birds that unite them together in a single group.
Your hypothesis has been disproved. It does not matter that there is no alternative that talks about "ancestors and descendants" "in the same level of detail" to replace it.
"If it was a population withing the original group of flying dromeosaurids, then it must have shared common ancestry with it."
ReplyDeleteWhat does that statement mean?
Does it mean something different than what I just said?
"A subgroup of dromaeosaurids settled on the land.
At that point, the ones that had settled on the ground developed into a set of modern flightless birds AND the rest of the flying dromaeosaurids developed into a set of modern flying birds.
I don't know. You tell me. If it does NOT mean something different, then you must also accept that a group diverged into two subgroups, with one "settling on land" and "the rest" keeping to the air. Those two subgroups shred common ancestry by definition, therefore you accept the idea of a common ancestor and your objections were moot.
ReplyDeleteIf it does not mean that, what does it mean?
And another thing I thought about: I have a friend who is distantly related to a famous politician of old. He and the descendants of that politician ACTUALLY share a common ancestor- the old politician.
Do you see that as impossible or just incorrect? Is it "cladistic thinking"?
"We POSTULATE that some basal members could fly, based on having (guess what?) A COMMON ANCESTOR with flying birds. When that ancestor lived, and whether flight ability was lost within Hesperornithes or sooner, is not yet known."
ReplyDeleteSo if we conclude that there were flying members of Hesperornithes, I am proposing that they developed into modern diving birds such as loons, grebes.
Are you in agreement with that idea or are you suggesting that they all went extinct and did not develop into any modern birds?
"I don't know. You tell me. If it does NOT mean something different, then you must also accept that a group diverged into two subgroups, with one "settling on land" and "the rest" keeping to the air. Those two subgroups shred common ancestry by definition, therefore you accept the idea of a common ancestor and your objections were moot."
ReplyDeleteYou say
"Those two subgroups shared common ancestry by definition,"
The flightless birds developed FROM the flying bird group when the subgroup split off and settled on the land.
I cannot make any sense of your phrase that they shared a common ancestor.
Are you saying that in addition to the original flying group (and the subgroup that split off from it), that there is another group?
And that that other group gave rise to both the flying and the flightless birds?
That is clearly not what I am saying.
"Actually its not just one bone. It is the whole arm and shoulder girdle in every specimen of Hesperornis and Baptornis which preserves them."
ReplyDeleteNobody has presented any other Hesperornis fossils with arm parts beyond the particular Hesperornis regalis fossil that we have been looking at. (The one that we have seen the picture of earlier). The particular one described by O.C. Marsh in 1877.
If anyone can present any other Hesperonis with any arm parts please do so.
As far as I can see we have ONLY the humerus arm part of ONE specific Hesperornis fossil.
I hope there is more, but I have never seen any other Hesperornis fossils with ANY arm parts.
So we are, as I said, back to one bone in one particular fossil discovered over 100 years ago labelled as a humerus.
Read the Oceans of Kansas website. Look at the photos of the specimens. The information is there if you choose to look. We have multiple individuals many of which preserve the arms. We have the complete shoulder girdle in multiple individuals. We are not dealing with "only the humerus arm part of one specific Hesperornis fossil". If you do not think it is a humerus what do you think it is? Show your working.
ReplyDeleteNote that we also have the arms of Baptornis- this too is greatly reduced and would be incapable of supporting the bird in the air, although it is not so reduced as Hesperornis
"The flightless birds developed FROM the flying bird group when the subgroup split off and settled on the land."
The flying bird group gave rise to other species, correct? It is these species share a common ancestor with species in the flightless bird group.
"I cannot make any sense of your phrase that they shared a common ancestor."
If you cannot understand the idea of two groups sharing a common ancestor then you will find it very difficult to criticise the mainstream theories.
"So if we conclude that there were flying members of Hesperornithes, I am proposing that they developed into modern diving birds such as loons, grebes."
Which means that the flightless hesperornithines share a common ancestor with the living grebes. (How about the diving ducks? where do they fit in?)
"Are you in agreement with that idea or are you suggesting that they all went extinct and did not develop into any modern birds?"
I would follow the conventional idea that they went extinct and have left no living descendants.
A Nonny Mouse posted:
ReplyDelete"Read the Oceans of Kansas website. Look at the photos of the specimens. The information is there if you choose to look."
I have read it. The information is not there.
If you think it is there, just copy and paste it here.
I am talking about the arm parts of Hesperornis.
A Nonny Mouse posted:
ReplyDelete"The flying bird group gave rise to other species, correct? It is these species share a common ancestor with species in the flightless bird group."
There was a group that gave rise to the flying dromaeosurids.
Later some of the flying birds split off and settled on the land and then lost their flying characteristics. This is classic cladogenesis.
Are you saying that that earlier group is the common ancestor of the flying dromaeosaurids and the subgroup of flying dromeisuarids
One group gave rise to another group which later gave rise to another group.
It seems that in that case you want to call the first group the common ancestor of both the groups that came after.
For example:
1st group ---> 2nd group ---> 3rd group
In this case you want to call group 1 the common ancestor of group 2 and group 3.
Is that right?
I fail to comprehend your confusion. I am not saying that there is a third group; I am saying that a specific population from one group gave rise to another group.
ReplyDeleteThat population was initially part of the same, ONE group. Therefore the new subgroup shared common ancestry with the "rest" of the group.
How can it be otherwise?
Note in the case we are talking about, that the 2nd group continued as a flying group in parallel with the subgroup that split off and settled on the land. Both groups continued to develop on their separate lines.
ReplyDeleteI hope that part is clear.
"Are you in agreement with that idea or are you suggesting that they all went extinct and did not develop into any modern birds?"
ReplyDelete"I would follow the conventional idea that they went extinct and have left no living descendants."
This is the main difference between the consensus mainstream thinking and the "parallel lines" idea I am talking about.
Note:
Remember please that the total idea I am talking about is:
1)that pterosaurs developed into primitive bird groups and
2) the primitive bird groups (lines) developed in parallel lines, into modern birds.
"That population was initially part of the same, ONE group. Therefore the new subgroup shared common ancestry with the "rest" of the group."
ReplyDeleteDoes common ancestry mean that they both have the same ancestor?
If not, what does common ancestry mean?
"A Nonny Mouse posted:
ReplyDelete"Read the Oceans of Kansas website. Look at the photos of the specimens. The information is there if you choose to look."
I have read it. The information is not there.
If you think it is there, just copy and paste it here.
I am talking about the arm parts of Hesperornis".
I copied the reference and the relevant text a few comments ago. You paid no attention to it. I hope you'll do so now. Anyway, here it is again:
http://oceansofkansas.com/hesperornis.html
"The wings were represented by the humerus only, which is long and slender, and without any trace of articulation at its distal end".
"Note that the wing (upper limb) in Hesperornis was very reduced in size and probably non-functional".
Notice that that site alone describes not one, but THREE different specimens, one of which is the one described in 1877.
We will eventually get to the point where we need to distinguish between the concept of "last common ancestor" on the one hand and "common ancestor" on the other hand.
ReplyDeleteAt times it looks like people here use both terms interchangeably.
"Common ancestry" is a standard evolution idea. "Last common ancestor" is a cladistic term that means something else.
But let's just continue to work on what people mean by "common ancestor" to begin with.
"Notice that that site alone describes not one, but THREE different specimens, one of which is the one described in 1877."
ReplyDeleteAnd only that one - which is the one described in 1877 - shows any arm parts at all. It shows just the humerus.
Right?
I am asking about the other Hesperornis fossils.
Did they find arm parts for any of them?
The site gives no info on that question.
"And only that one - which is the one described in 1877 - shows any arm parts at all. It shows just the humerus.
ReplyDeleteRight"?
Apparently you haven't read the accompanying text.
The two colored pictures of the humerus (one on the reconstructed skeleton, one on display) are from two specimens respectively.
It appears that no arm parts were ever found for any Hesperornis other than the one particular one we have been talking about - which is the one described by Marsh in 1877.
ReplyDeleteAnd that we have seen the fossil picture of.
And that one fossil has just one humerus bone (at least that is how they labelled it).
In other words we really know next to nothing about the wings of Hesperornis.
And on the basis of that from over 100 years ago people have concluded that Hesperornis is flightless.
But it is not that I want there to be no other evidence. I dearly would love to see more evidence of Hesperornis arm parts -particularly the humerus.
So if thee is more fossil evidence of any Hesperornis arm parts on any other fossils I really would like to know about it.
It appears that no arm parts were ever found for any Hesperornis other than the one particular one we have been talking about - which is the one described by Marsh in 1877.
ReplyDeleteAnd that we have seen the fossil picture of.
And that one fossil has just one humerus bone (at least that is how they labelled it).
In other words we really know next to nothing about the wings of Hesperornis.
And on the basis of that one fossil, from over 100 years ago, people have concluded that Hesperornis is flightless.
But it is not that I want there to be no other evidence. I dearly would love to see more evidence of Hesperornis arm parts -particularly the humerus.
So if there is more fossil evidence of any Hesperornis arm parts on any other fossils I really would like to know about it.
Harry Seeley posted:
ReplyDelete"Apparently you haven't read the accompanying text.
The two colored pictures of the humerus (one on the reconstructed skeleton, one on display) are from two specimens respectively."
Is this what you are referring to Harry Seeley:
http://www.oceansofkansas.com/Hesperornis.html
LEFT: FHSM VP-2293 - Two views of the right humerus - Note that the wing (upper limb) in Hesperornis was very reduced in size and probably non-functional."
"Dr. Pterosaur said...
ReplyDeleteWe will eventually get to the point where we need to distinguish between the concept of "last common ancestor" on the one hand and "common ancestor" on the other hand.
At times it looks like people here use both terms interchangeably.
"Common ancestry" is a standard evolution idea. "Last common ancestor" is a cladistic term that means something else.
But let's just continue to work on what people mean by "common ancestor" to begin with."
I'm sure why this concept is so hard to understand.
All Last Common Ancestors are Common Ancestors, but not all Common Ancestors are Last Common Ancestors.
For example you and your brother share many common ancestors - grandfathers, great great grandfathers, great great great grandmothers etc. Those are all common ancestors. But the LAST common Ancestor between you and your brother is your father.
In evolutionary scale, all life is united by a common ancestor. Some manner of single celled organism that existed many miilions of years of ago. As you begin to group organisms you move further up the chain so to speak. Chimps and Humans share a much closer LCA than do Humans and Fish.
This is not a cladistic thing. It's just simple relationships between living things.
Hope this helps
Here is a heads-up to people.
ReplyDeleteIf you make an error with your tags, the software does not accept your post. (It does nothing with your post so it just remains on the screen). Unfortunately it does not tell you that you made an error. Check your tags if that happens.
Hello Turnadout.
ReplyDeleteSo you agree that "last common ancestor" and "common ancestor" are not synonymous.
They cannot be used interchangeably.
But they still have different meanings. In cladistics the "last common ancestor" is actually the first creature of the new species.
On the other hand, "common ancestor" refers to the previous creature type FROM WHICH the new species evolved*.
And by the way, all analogies with humans and fathers etc. fail because they are not based on the change from one type of creature to another. Our father and grandfather etc. are still humans.
*Cladistics is not as straightforward as people think and it has a lot of buried assumptions in it.
"Note in the case we are talking about, that the 2nd group continued as a flying group in parallel with the subgroup that split off and settled on the land. Both groups continued to develop on their separate lines."
ReplyDeleteAnd therefore the later members of the second group share a common ancestor with the flightless group that split off from earlier members of the second group.
"But they still have different meanings. In cladistics the "last common ancestor" is actually the first creature of the new species.
On the other hand, "common ancestor" refers to the previous creature type FROM WHICH the new species evolved."
Wrong. Species are often still capable of limited interbreeding after they have diverged. They are usually extremely similar. The LCA is not the first member of the new species, but the last member of the old species that the new species can be traced back to.
"And by the way, all analogies with humans and fathers etc. fail because they are not based on the change from one type of creature to another. Our father and grandfather etc. are still humans."
Wrong again. Two species share a common ancestor. The last common ancestor is the point at which these two lineages diverge. Only after they diverge do the two species start to accrue differences through mutation and natural selection, genetic drift, sexual selection, etc. Only long after these two populations have diverged are they considered different enough to qualify as different "types". (And what is your definition of "type"? Does it correspond to family, genus, species? Or is it as variable as the creationists' definition of "kind"?) The discussion of parents and children is exactly accurate. The LCA of humans and chimps, of birds and pterosaurs, animals and plants, etc was an individual organism that lived and died. It would not be until much later that its descendants would be obviously different "types".
"It appears that no arm parts were ever found for any Hesperornis other than the one particular one we have been talking about - which is the one described by Marsh in 1877."
Wrong. There are others- you can see pictures of them on the website. As Harry notes it mentions three other specimens- and there are more than that.
"Is this what you are referring to Harry Seeley:
http://www.oceansofkansas.com/Hesperornis.html
LEFT: FHSM VP-2293 - Two views of the right humerus"
Not just that. There are other specimens which preserve the humerus and are also illustrated on that page. The mounted skeleton for one.
"But it is not that I want there to be no other evidence. I dearly would love to see more evidence of Hesperornis arm parts -particularly the humerus."
You've been shown the humerus. What is your grounds for claiming it is not a humerus? Why should we believe your claims that it is mislabelled over those of every palaeontologist who has examined the specimen first hand, compared it with other humeri, and produced mounted specimens articulating it precisely in the shoulder girdle (which is also preserved, and coincidentally show that the animals in question could not fly)? Or have they mislabelled the coracoid, scapula and sternum? What are they if they're mislabelled.
"Dr. Pterosaur said...
ReplyDeleteHello Turnadout.
So you agree that "last common ancestor" and "oommon ancestor" are not synonymous.
They cannot be used interchangeably. "
Well yes and no. In discussions like you're having here, it's pretty much assumed when using common ancestor that you are talking about the last common ancestor. As to interchangeability, well you can replace last common ancestor with common ancestor without problem since a last common ancestor is by definition still a common ancestor.
They are interchangeable in the same sense that "sports" and "baseball" are interchangeable. You can say a person playing baseball is playing a sport but you can't necessarily say that a person playing a sport is playing baseball.
"But they still have different meanings. In cladistics the "last common ancestor" is actually the first creature of the new species*.
On the other hand, "common ancestor" refers to the previous creature type FROM WHICH the new species evolved*. "
Could you please provide links and copy and paste the relevant parts supporting this statement? This appears to be a misunderstanding on your part.
"And by the way all analogies with humans and fathers etc. fail because they are not based on the change from one type of creature to another. Our father and grandfather etc. are still humans."
Unless you are a clone of your father then the analogy is apt. Unless you are suggesting that one creature gives birth to a different type of creature, then the analogy is apt.
Regardless it's just a simple analogy. It works just as well using Humans, chimps and fish or any other organisms you like. Humans, chimps and fish share a last common ancestor. However, the last common ancestor between humans and chimps is much closer to them than the LCA uniting all 3.
http://en.wikipedia.org/wiki/Most_recent_common_ancestor
ReplyDelete"In genetics, the most recent common ancestor (MRCA) of any set of organisms is the most recent individual from which all organisms in the group are directly descended. The term is often applied to human genealogy.
The MRCA of a set of individuals can sometimes be determined by referring to an established pedigree. However, in general, it is impossible to identify the specific MRCA of a large set of individuals, but an estimate of the time at which the MRCA lived can often be given. Such time to MRCA (TMRCA) estimates can be given based on DNA test results and established mutation rates as practiced in genetic genealogy, or by reference to a non-genetic, mathematical model or computer simulation.
The term MRCA is usually used to describe a common ancestor of individuals within a species. It can also be used to describe a common ancestor between species. To avoid confusion, last common ancestor (LCA) or the equivalent term concestor is sometimes used in place of MRCA when discussing ancestry between species.
Yes.
ReplyDelete"the most recent common ancestor (MRCA) of any set of organisms is the most recent individual from which all organisms in the group are directly descended. "
What is the problem? This is exactly what people have been telling you
"Is this what you are referring to Harry Seeley:
ReplyDeletehttp://www.oceansofkansas.com/Hesperornis.html
LEFT: FHSM VP-2293 - Two views of the right humerus"
"Not just that. There are other specimens which preserve the humerus and are also illustrated on that page. The mounted skeleton for one."
That is two views of the same humerus.
There is only one humerus in one fossil.
Turnadout said...
ReplyDeleteYes.
"the most recent common ancestor (MRCA) of any set of organisms is the most recent individual from which all organisms in the group are directly descended. "
What is the problem? This is exactly what people have been telling you
Do you understand the difference between the creatures of the previous species and the first creature of the new species? Those are not the same thing.
That is the difference I am talking about.
The "common ancestor" refers to the previous species.
The "last common ancestor" idea (even though it uses some of the same words) refers to the new species.
That is how one species evolves into another.
Actually it is more complicated than that, but this is a place to begin.
Cladistics is not straightforward and includes a number of buried assumptions.
But I am being sucked into an argument about cladistics and I know from lots of experience that cladists cannot understand the simplest thing if it contradicts the ideas they think are correct.
They will pretend to not get the simplest thing.
My mistake. It looks like both FHSM VP-2069 and FHSM VP-2293 show one humerus each.
ReplyDeleteAnd neither shows a second humerus for that creature nor any other arm parts. So the evidence is all the way up to two partial arm parts from incomplete specimens over 100 years ago.
And I had asked before about all the other Hesperornis species that have been found since. There does not seem to be any info about arm parts available for any of them. But perhaps there is - I would be very interested.
http://en.wikipedia.org/wiki/Hesperornis
H. regalis Marsh, 1872 (type)
H. crassipes (Marsh, 1876) [originally Lestornis]
H. gracilis Marsh, 1876
H. altus (Marsh, 1893) [originally Coniornis]
H. montana Schufeldt, 1915
H. rossicus Nesov & Yarkov, 1993
H. bairdi Martin & Lim, 2002
H. chowi Martin & Lim, 2002
H. macdonaldi Martin & Lim, 2002
H. mengeli Martin & Lim, 2002
"That is two views of the same humerus.
ReplyDeleteThere is only one humerus in one fossil".
No. Did you even try to read the text?
The two pictures, of the reconstructed skeleton and the standalone display, are two different specimens: FHSM VP-2069 and FHSM VP-2293.
Both are different than the old 1877 specimen (YPM 1206).
That makes three.
Check again.
One group gave rise to another group which later gave rise to another group.
ReplyDeleteIt seems that in that case you want to call the first group the common ancestor of both the groups that came after.
For example:
1st group ---> 2nd group ---> 3rd group
In this case you want to call group 1 the common ancestor of group 2 and group 3.
Is that right?
Is the 1st group a last common ancestor? If so of what?
Is the 2nd group a last common ancestor? If so of what?
What you described about secondarily flightless dromeosaurids, specifically, was not "One group gave rise to another group which later gave rise to another group".
ReplyDeleteSome memebrs of the group "settled on land" and developed to flightless forms, while "the rest" went on to develop to primitive flying birds (enantiornithes group).
So we have
Flying dromeosaurids----> Enantiornithe group
|
'-------------> Flightless dromeosaurids
Or
1st group--------> 3rd group
|
'-------> 2nd group
"Do you understand the difference between the creatures of the previous species and the first creature of the new species? Those are not the same thing.
ReplyDeleteThat is the difference I am talking about."
Speciation is not an instant process. The members of each successive generation can breed with the one before, and the one after. Its only when you compare individuals hundreds or thousands of generations apart that you see that speciation has occurred.
"One group gave rise to another group which later gave rise to another group.
It seems that in that case you want to call the first group the common ancestor of both the groups that came after."
No. One group gave rise to another group. The first group then either persists to this day or gives rise to a third independently from the second.
Group 1 contains the last common ancestor of group 2, and group 2 contains the last common ancestor of group 3. If group 1 is a species and group 2 an entire family then group 1 is indeed the LCA of group 2. But the species in a family don't all give rise to other families. Only a single species within that family with be ancestral to the third family, and would be its LCA.
As for Hesperornis, surely if the wing bones were as robust as they would need to be to support a bird of its size in the air why are they never found? Why do the articulated specimens have a tiny splint of bone that exactly corresponds to the position of the humerus in all other birds, and articulates with the shoulder joint as in all other birds? Why is there no evidence of an articulation point at the end for the forearm and hand? Why are you ignoring this crucial point that shows your contention to be wrong? It would not matter if we only had a single humerus. It articulates with the greatly reduced shoulder girdle. It can be nothing other than a humerus.
You are also ignoring the fact that much of the arm is known in the related Baptornis. (Specimen KUVP 2290) It that species the humerus is 10cm long, and the radius and ulna 2cm long. A wing of about six inches is not enough to lift a heavy three-foot long bird off the ground.
The other species are unlikely to help you much I'm afraid. Most are almost certainly from far poorer remains that Hesperornis regalis
"Speciation is not an instant process. The members of each successive generation can breed with the one before, and the one after. Its only when you compare individuals hundreds or thousands of generations apart that you see that speciation has occurred."
ReplyDeleteThat is one of the assumptions built into cladistics.
Right?
And yet more current research is leaning towards saltation.
So that means that one of the buried assumptions of cladistics may be wrong.
That is significant.
My major point is not that saltation is significant (even though it is) but to point out the buried assumption in cladistics.
"As for Hesperornis, surely if the wing bones were as robust as they would need to be to support a bird of its size in the air why are they never found?"
ReplyDeleteWhat makes you say that the humerus is not sufficient? It is certainly long enough. All that is missing are the other parts of the arm.
You are basing the total of your conclusion on these two bones from over 100 years ago (that may have even been mislabelled).
My argument is not that they have been mislabeled. But I expect someone to try to spin the argument that way. Someone already did try.
"That is one of the assumptions built into cladistics.
ReplyDeleteRight? "
No that is what the evidence shows with regards to evolutionary theory as a whole.
"And yet more current research is leaning towards saltation.
So that means that one of the buried assumptions of cladistics may be wrong.
That is significant.
My major point is not that saltation is significant (even though it is) but to point out the buried assumption in cladistics."
Are you suggesting that one species of creature gives birth to an entirely new species of creature? Because unless you are then...
"Speciation is not an instant process. The members of each successive generation can breed with the one before, and the one after. Its only when you compare individuals hundreds or thousands of generations apart that you see that speciation has occurred."
"You are basing the total of your conclusion on these two bones from over 100 years ago (that may have even been mislabelled)."
ReplyDeleteWhy does it matter when the bones were found? People today do all kinds of research from bones found that long ago.
And for what it's worth, just because the bones were found then, doesn't mean that's when they were labelled. For instance that OceansofKansas page was last updated 08/17/2011.
"What makes you say that the humerus is not sufficient? It is certainly long enough. All that is missing are the other parts of the arm. "
What missing parts of the arm? Can you please provide links and copy and paste the relevant parts that support that there is more to the arm?
"You are also ignoring the fact that much of the arm is known in the related Baptornis. (Specimen KUVP 2290) It that species the humerus is 10cm long, and the radius and ulna 2cm long. A wing of about six inches is not enough to lift a heavy three-foot long bird off the ground."
ReplyDeleteThey found the other parts of the wing for at least one Baptornis.
Is your point that its close relative Hesperonis only had a humerus?
"Why does it matter when the bones were found? People today do all kinds of research from bones found that long ago."
ReplyDeleteMy point is that a number of other members of Hesperonis have been found (some fairly recently). I listed them twice*.
Does anyone know if any arm parts have been found for any of them?
* http://en.wikipedia.org/wiki/Hesperornis
H. regalis Marsh, 1872 (type)
H. crassipes (Marsh, 1876) [originally Lestornis]
H. gracilis Marsh, 1876
H. altus (Marsh, 1893) [originally Coniornis]
H. montana Schufeldt, 1915
H. rossicus Nesov & Yarkov, 1993
H. bairdi Martin & Lim, 2002
H. chowi Martin & Lim, 2002
H. macdonaldi Martin & Lim, 2002
H. mengeli Martin & Lim, 2002
This is turning into an unpleasant argument - much like political arguments.
ReplyDeleteThat is often the case.
I will stop shortly.
It looks like Hesperornis flew. If not other Hesperornithes did*.
But the more important point from my perspective is that the Hesperonithes developed into the modern diving birds.
That is part of the "parallel lines" idea that I have been proposing - based on parallel evolution.
You can see all the lines that I have proposed summarized in my most recent posts.
Since nobody has given an alternative I am content to move on.
When someone offers an alternative we can evaluate it.
*"The Hesperornithidae are obviously derived from flying birds, and thus, contrary to the sweeping generalizations about the flightlessness of all hesperornithiform birds (Martin, 1983), some of their small relatives must have been capable of flight,
"The two pictures, of the reconstructed skeleton and the standalone display, are two different specimens: FHSM VP-2069 and FHSM VP-2293.
ReplyDeleteBoth are different than the old 1877 specimen (YPM 1206).
That makes three."
You may be right but I do not see that.
I see mention of 1206 but no mention of any humerus.
Can you copy and paste what you are seeing that makes you think that 1206 had a humerus?
"some of their small relatives must have been capable of flight,"
ReplyDeleteWhich would those be? Could you name them please?
Turnadout you need to research current thinking about saltation*.
ReplyDeleteMy point is that cladistics includes a set of assumptions that are not correct.
* You might find this interesting:
http://www.allbusiness.com/science-technology/life-forms-mammals-primates/14093863-1.html
" "It isn't the accumulation of events that causes a speciation, it's single, rare events falling out of the sky, so to speak. Speciation becomes an arbitrary, happy accident when one of these events happens to you.""
But I am not interested in along argument.
Ta Dah said...
ReplyDelete"some of their small relatives must have been capable of flight,"
Which would those be? Could you name them please?"
I do not know them.
But the important point from my point of view is that flying Hesperornithes are the ancestors of flying modern diving birds like loons, grebes. That is what I am proposing
That is part of the parallel lines idea I am proposing.
What is your alternative? That ALL modern birds came from one line?
But perhaps you can help me, because this diagram seems to indicate that even establishment consensus thinking believes there were multiple lines. I am just proposing more of them. Your help would be appreciated on this.
http://upload.wikimedia.org/wikipedia/commons/f/f3/Neornithes.jpg
"But I am not interested in along argument."
ReplyDeleteOf course not. Because you did not understand what the article was saying.
Here's a hint:
"The key point emerging from the statistical evidence, Pagel stresses, is that the trigger for speciation must be some single, sharp kick of fate that is, in an evolutionary sense, unpredictable. "We're not saying that natural selection is wrong, that Darwin got it wrong," Pagel adds. Once one species has split into two, natural selection will presumably adapt each to the particular conditions it experiences. The point is that this adaptation follows as a consequence of speciation, rather than contributing as a cause. "I think what our paper points to - and it would be disingenuous for very many other people to say they had ever written about it - is what could be, quite frequently, the utter arbitrariness of speciation. It removes speciation from the gradual tug of natural selection drawing you into a new niche," he says."
"Ta Dah said...
ReplyDelete"some of their small relatives must have been capable of flight,"
Which would those be? Could you name them please?"
I do not know them. "
So some unnamed, unknown creature?
Hmmm... isn't this an issue for you?
Harry Seeley posted:
ReplyDeleteOr
1st group--------> 3rd group
|
'-------> 2nd group
That is not comparable to what I was saying. In what I posted the 3rd group evolved from the 2nd group.
This would be more like what I am saying:
1st group------> a 2nd group --> a 3rd group
|
'-------> a 2nd group --> a 3rd group
So some unnamed, unknown creature?
ReplyDeleteHmmm... isn't this an issue for you?
I wondered if you were slyly going down that road. The difference is that I am saying that those creatures are directly on the line.
Cladists do not do that.
They do not specify the creatures on the line(s).
Do you see what I mean?
Turnadout I have already had a long unpleasant discussion about Pagel's study with people who like you wanted to pretend that the study is not saying what it obviously is saying.
ReplyDeleteI am not interested in another argument.
My point is that cladistics includes some buried assumptions.
Anyone can respond to this:
ReplyDeleteBut perhaps you can help me, because this diagram seems to indicate that even establishment consensus thinking believes there were multiple lines. I am just proposing more of them. Your help would be appreciated on this.
http://upload.wikimedia.org/wikipedia/commons/f/f3/Neornithes.jpg
For example, you can see from this diagram that anseriformes and galliformes are branches that run "parallel" to the other lines up to the current time.
ReplyDeleteThose are like two of the lines I am talking about.
You can also see that the diagram includes presbyornithidae and ichthyornithiformes but has them ending at 66 mya. I am proposing that like the other "parallel lines" those lines continued to modern bird lines.
There is more to it than that but this diagram shows how current thinking accepts parallel lines and with almost no change, it is what I am proposing.
"That is one of the assumptions built into cladistics.
ReplyDeleteRight?"
Wrong. This has been part of evolutionary theory since Darwin. It is not part of cladistics at all.
"This would be more like what I am saying:
1st group------> a 2nd group --> a 3rd group
|
'-------> a 2nd group --> a 3rd group"
This is a polyphyletic group. Neither evolutionary systematics nor cladistics accepts these groups as natural. And your "evidence" that birds are polyphyletic is utterly shredded when you look at the characters shared between all of them- characters I have listed above and you have ignored.
"I wondered if you were slyly going down that road. The difference is that I am saying that those creatures are directly on the line.
Cladists do not do that.
They do not specify the creatures on the line(s)."
As you well know no-one else proposes that specific species are "on the lines" because there is no method for establishing ancestor-descendant relationships based on such sparse remains. As you have been told multiple times.
"Turnadout I have already had a long unpleasant discussion about Pagel's study with people who like you wanted to pretend that the study is not saying what it obviously is saying."
It is not saying that speciation is instant nor that diversification is if that's what you're thinking.
"There is more to it than that but this diagram shows how current thinking accepts parallel lines and with almost no change, it is what I am proposing."
You are reading it wrong. Look at how the lines join up. The galliformes and the anseriformes are closer to each other than to the other lineages. You are proposing breaking up the Neoaves into its constituent parts and scattering them liberally about the place. You are proposing birds evolved each and every character unique to birds independently. The parallel evolution required for this is multiple orders of magnitude higher than the alternative- that webbed feet and similar adaptations evolved more than once. A position that you accept anyway s you have not removed the diving ducks from the rest of the ducks.
"What makes you say that the humerus is not sufficient? It is certainly long enough. All that is missing are the other parts of the arm."
Wrong again. The humerus is six inches long. Bird humeri are the longest bone in the wing. There is no way an animal can fly with a wing that small. You are also ignoring the fact that it is nowhere near as robust as is required for flight. Many flightless birds have significantly bigger wings relative to their size than the Hesperornithines.
"They found the other parts of the wing for at least one Baptornis.
Is your point that its close relative Hesperonis only had a humerus?"
No. My point is that Baptornis also had a six inch wing. Which was also not strong enough to support a three foot long bird in the air. Hesperornis' wing was comparable in size. On bird twice as big.
"It looks like Hesperornis flew. If not other Hesperornithes did"
No. Hesperornis did not fly. It does not look like that at all. No-one disagrees with the second sentence, but we do not have conclusive evidence either way of any flying hesperornithiform.
"That is not comparable to what I was saying. In what I posted the 3rd group evolved from the 2nd group.
ReplyDeleteThis would be more like what I am saying:
1st group------> a 2nd group --> a 3rd group
|
'-------> a 2nd group --> a 3rd group"
Your diagram has "2nd group" and "3rd group" twice. Are they the same group? If so, your disgram makes no sense in relation to flightless dromeosaurids. If it's not the same group, then how is it different to what I am proposing? See below.
Let's use initial so avoid confusion, and also expand the lineages a bit.
We start with a group of flying dromeosaurids (FD). Some members of the group "settle on land", and then develop to flightless dromeosaurids (!FD). 'The rest' maintain flight, and eventually develop to flying enantiornithes (FE). Flightless dromeosaurids develop into (also flightless) ornithomimosaurids (!FO).
So we have:
FD--->FE
|
'-->!FD-->!FO
Now let's expand to include the aquatic lineage. A *subgroup* of flying enantiornithes develops aquatic characteristics (the characteristics have to appear at that point, since you do not propose a different, 'aquatic' group of dromeosaurids for your lineage, but use Microraptor and Rahonavis in both lineages as an example).
Those flying aquatic enantiornithes (FAE) develop to (also flying) hesperornithes (FH). So we have:
,--->FE (other flying hesperornithes)
|
FD--->FE--->FAE--->FH
|
'-->!FD-->!FO
Looks like those parallel lines seem more and more like a tree. But it goes on. From those flying hesperormithes, SOME* (like Hesperornis) also become secondarily flightless (!FH), while the rest develop to modern aquatic birds (MAB):
,--->FE(other flying hesperornithes)
|
FD--->FE--->FAE--->FH------->MAB
| |
| '--->!FH
|
'--->!FD--->!FO
And if we include the development of modern flightless birds (!FMB), and all the other lineages of modern birds, we have:
,--->FE(other)-------->MB(other)
|
FD--->FE--->FAE--->FH-------->MAB
| |
| '--->!FH
|
'--->!FD--->!FO------------->!FMB
Is this correct so far? If not, where exactly and how am I diverging from your proposed lineages?
(*) Please don't tell me that Hesperornis could fly, and that we have no evidence for flightless hesperornithes. We've beat that one to death and, after all, as you have repeatedly shown, you were content with SOME members of hesperornithes -not ALL- being able to fly.
This would be more like what I am saying:
ReplyDelete1st group------> a 2nd group --> a 3rd group
|
'-------> a 2nd group --> a 3rd group
I should make it clear that the 2nd group in the top line is not the same type of creatures as the 2nd group in the bottom line.
And the 3rd group in the top line is not the same type of creatures as the 3rd group in the bottom line.
For example, take the 1st group as flying dromaeosaurs, the top 2nd group as primitive flying birds and the top 3rd group as modern flying birds.
And take the bottom 2nd group as primitive flightless birds and the bottom 3rd group as modern flightless birds.
"You may be right but I do not see that.
ReplyDeleteI see mention of 1206 but no mention of any humerus.
Can you copy and paste what you are seeing that makes you think that 1206 had a humerus"?
First of all, you can see the humerus in the restoration (black and white photo). Also, the first description we quoted to you is a diagnosis of features included in specimen YBM 1206. Marsh states
"The most perfect specimen of this species yet discovered (number 1206) was obtained by Mr. T.H. Russell and the writer in October, 1872 [EDIT: that is the 1206 specimen, as noted previously in the text]. This skeleton was nearly complete when found, the skull, lower jaws, and pelvis being especially well preserved. The locality was near that of the type specimen. Another important skeleton (number 1207) was found in July, 1875, by Prof. B. F. Mudge, who was then in charge of one of the writer's exploring parties."
I can also check and quote a fossil database when I get to work, and confirm that 1206 had a humerus. Will that suffice?
"We start with a group of flying dromeosaurids (FD). Some members of the group "settle on land", and then develop to flightless dromeosaurids (!FD). 'The rest' maintain flight, and eventually develop to flying enantiornithes (FE). Flightless dromeosaurids develop into (also flightless) ornithomimosaurids (!FO)."
ReplyDeleteI am not proposing that dromaeosaurids evolved into flightless dromaeosaurids. If you look at my chart you see that the flying dromaeosaurids that settled on the land developed into flightless ornithomimosaurids.
In other words there is no separate taxon of flightless dromaeosaurids.
Is that clear?
There is an aspect of the diving Hesperornis that we have not thought of.
ReplyDeleteIf the humerus is too weak for flight then when the bird was "flying" under the water it would break.
Something does not add up here.
Anyone can respond to this:
ReplyDeleteBut perhaps you can help me, because this diagram seems to indicate that even establishment consensus thinking believes there were multiple lines. I am just proposing more of them. Your help would be appreciated on this.
http://upload.wikimedia.org/wikipedia/commons/f/f3/Neornithes.jpg
I want to relate everything we are talking about to this diagram.
Also note that this diagram is missing Hesperornithes. It should be on there.
Could someone please indicate where they think Hesperornithes should be placed? In other words where it would start and where (in current thinking) it would end.
That would be very helpful.
No-one suggests that hesperorntihines "flew" under water either. They are foot propelled divers, as you keep saying. Their wings were vestigial.
ReplyDelete"I am not proposing that dromaeosaurids evolved into flightless dromaeosaurids. If you look at my chart you see that the flying dromaeosaurids that settled on the land developed into flightless ornithomimosaurids."
What about the fact that the majority of dromaeosaurs were flightless? Where do they go? Did the flying dromaeosaurs "develop" straight into flightless ornithomimids? Or was there an intermediate form?
(And we shall leave aside the fact that the arms of ornithomimids have less in common with any modern bird than the arms of dromaeosaurids- another set of unparsimonious reversals that your theory necessitates)
"But perhaps you can help me, because this diagram seems to indicate that even establishment consensus thinking believes there were multiple lines. I am just proposing more of them. Your help would be appreciated on this."
ReplyDeleteDo you see how all the lines join up? And some meet up and continue as a single line before meeting others. Once the lines separate they do not meet again. But when they meet they meet in a single species that was the last common ancestor of the two groups. No-one proposes that these species evolved their birdlike characters independently of each other, as you do, but inherited them from their ancestor.
"Also note that this diagram is missing Hesperornithes. It should be on there."
Hesperornithines are not Neornithines. They would join below the point where ichthyornithiformes meet. Your ideas involve taking things out of neoaves and moving them around. It means Neoaves is not a natural group as recognised by any taxonomic methodology.
"I am not proposing that dromaeosaurids evolved into flightless dromaeosaurids. If you look at my chart you see that the flying dromaeosaurids that settled on the land developed into flightless ornithomimosaurids.
ReplyDeleteIn other words there is no separate taxon of flightless dromaeosaurids.
Is that clear"?
No, I'm afraid. We most certainly DO have flightless dromeosaurids. Not Ornithomimids, but families of dromeosaurids that could not fly. In fact, most families of dromeosaurids seem to have no flying members, while only two seem to ahva one flying member each.
Where did those flightless dromeosaurids come from? Creatures like Deinonyx, Achillobator and Utaraptor?
And what about Mahakala? A while ago, you insisted that it was "secondarily flightless". It most certainly was a dromeosaurid.
So flightless dromeosaurids do exist, and you need to account for them.
Now, perhaps you do not think that flying dromeosaurids are part of the development of flightless birds, and ornithomimids developed separately from flying dromeosaurids. But that only complicates your lineage further:
. ,--->FE(other)-------->MB(other)
|
FD--->FE--->FAE--->FH-------->MAB
|| |
|| '--->!FH
||
|'--->!FO------------->!FMB
|
'-------->!FD
Because from flying fromeosaurids we have both "secondarily flightless" dromeosaurids, AND flightless ornithomimids.
"There is an aspect of the diving Hesperornis that we have not thought of.
ReplyDeleteIf the humerus is too weak for flight then when the bird was "flying" under the water it would break.
Something does not add up here".
Hesperornis was not "flying" under the water. It was foot-propelled, not wing propelled.
Here's another chart, taking into account your position that some flying dromeosaurids "settled on land" and developed into ornithomimids (flightless):
ReplyDelete,--->!FD
|
| ,--->FE(other)--->FMB(other)
| |
| |
FD--->FE--->FAE--->FH--->FMAB
| |
| |
| |
| '--->!FH
'--->!FO--->!FMB
FD = Flying Dromeosaurids
!FD = Flightless Dromeosaurids
!FO = Ornithomimids (flightless)
FE = Esperornithes (flying)
FAE = Aquatic Esperornithes (flying)
FH = Hesperornithes (flying)
!FH = Flightless Hesperornithes
FMAB = Flying Modern Aquatic Birds
!FMB = Flightless Modern Birds
FE(other) = Other members of flying hesperornithes (other bird lineages)
MB(other) = Other members of modern flying birds (other bird lineages)
A few notes:
-Now your theory requires both ornithomimids AND flightless dromeosaurids diverging from flying dromeosaurids (flightless dromeosaurids most definitely exist- see most families of dromeosaurids, and remember your claims about Mahakala)
-Aquatic characters in the aquatic bird line need to appear in the enantiornithes stage, creating another divergence (aquatic morphology cannot appear sooner in the flying dromeosaurid stage, since you have the same examples -Microraptor and Rahonavis) at the start for both aquatic and flightless lineages)
-Whether some of hesperornithes could fly or not, since SOME hesperornithes definitely WERE flightless, you have another divergence to secondary flightlessness at a later stage.
Again: am I representing your lineages wrong, and if so, where and how exactly?
Harry Seeley posted:
ReplyDelete"Hesperornis was not "flying" under the water. It was foot-propelled, not wing propelled."
I get a kick out of someone who can with such confidence say something that he has no idea if it is actually true or not.
And do not forget that foot propelled modern birds use their wings.
The fact that Hesperornis was foot propelled simply adds to the conclusion that like modern birds they also used their wings.
I have put a few links on this post of underwater birds.
http://pterosaurnet.blogspot.com/2011/10/aquatic-birds.html
Take note of this:
ReplyDeletehttp://oceansofkansas.com/hesperornis.html
"LEFT: FHSM VP-2293 - Two views of the right humerus - Note that the wing (upper limb) in Hesperornis was very reduced in size and probably non-functional."
If in the opinion of these folks the wing was "probably non-functional" then they are also saying that POSSIBLY it was functional.
It is wrong for people here to make definitive statements that Hesperonis could not fly.
And as I have pointed out the evidence points to the idea that it could fly.
"Hesperornithines are not Neornithines. They would join below the point where ichthyornithiformes meet. Your ideas involve taking things out of neoaves and moving them around. It means Neoaves is not a natural group as recognised by any taxonomic methodology."
ReplyDeleteIt means very little to me for you to say that Neoaves is "not a natural group as recognised by any taxonomic methodology" since I am pointing out that Neoaves is not correct.
At best, Neoaves is a wastebasket taxon.
Instead of one line called Neoaves, we need a few separate lines. One line for landbirds, one line for seabirds etc.
Just as we have separate lines for Anseriformes and Galliformes etc.
"Do you see how all the lines join up? And some meet up and continue as a single line before meeting others. Once the lines separate they do not meet again. But when they meet they meet in a single species that was the last common ancestor of the two groups. No-one proposes that these species evolved their birdlike characters independently of each other, as you do, but inherited them from their ancestor."
ReplyDeleteBut when they meet they meet in a single species that was the last common ancestor of the two groups."
Can you point out one of those single species please?
I don't see species on that chart at all.
It does not name the species. No individual species is listed. It is looking at the higher level phylogeny. But it is implicit in the diagram and all like it. Galliformes and Anseriformes diverged from a single species. Unless you think that a whole series of species of the early Galloanseriformes (before the two groups diverged) all simultaneously "developed" into one or the other group then the alternative is the conventional idea that there was a single species that all these animals can independently trace their descent to. You would do well to read Richard Dawkins' "The Ancestor's Tale" for an excellent illustration of this.
ReplyDelete"At best, Neoaves is a wastebasket taxon.
Instead of one line called Neoaves, we need a few separate lines. One line for landbirds, one line for seabirds etc.
Just as we have separate lines for Anseriformes and Galliformes etc."
You are proposing that the whole of Aves is a wastebasket taxon. You claim every feature which uniquely identifies an animal as being a bird was independently evolved five or six times. And then you claim your idea is more parsimonious. This is demonstrably not the case. You even agree that the characters you use to identify your "parallel lines" can evolve in parallel- you claim diving ducks are ducks, and not members of the wing (or foot)-propelled line (depending on the species of duck). You're not even applying your methodology consistently.
"The fact that Hesperornis was foot propelled simply adds to the conclusion that like modern birds they also used their wings."
No it doesn't. Not all foot-propelled divers use their wings. Some do. But not all. And they all have wings considerably bigger than those of Hesperornis. The videos you show of birds underwater are all of wing-propelled divers, NOT foot-propelled ones. They are not comparable to Hesperornis.
"If in the opinion of these folks the wing was "probably non-functional" then they are also saying that POSSIBLY it was functional.
It is wrong for people here to make definitive statements that Hesperonis could not fly."
It was six feet tall, and many of its bones were solid. Its arm was six inches long. How in the name of God do you think it managed to fly? Compare its shoulder girdle and arms to that of a loon. There is no way it could have got off the ground.
"And as I have pointed out the evidence points to the idea that it could fly."
Nonsense. Re-read everything we've posted about its arms.
"Now, perhaps you do not think that flying dromeosaurids are part of the development of flightless birds, and ornithomimids developed separately from flying dromeosaurids"
ReplyDeleteI do not see this as being so comlpicated as you are imagining.
There were flying dromaeosaurids.
Some of them began spending more and more time on the ground and found that they could make a living that way.
They were still "flying" dromaeosaurids but they just did not fly that much any more. They found they did not need to do so. Then perhaps over time they slowly lost some of their flying characteristics.
Then some of those creatures developed into ornithomimids and the rest died off.
It seems simple to me.
Your thoughts?
Reposting my chart, hoping it will show up correctly this time::
ReplyDelete,--->!FD..........................
|.................................
|......,--->FE(other)--->FMB(other)
|......|..........................
|......|..........................
FD--->FE--->FAE--->FH-------->FMAB
|..................|..............
|..................|..............
|..................|..............
|..................'--->!FH.......
'--->!FO--------------------->!FMB
FD = Flying Dromeosaurids
!FD = Flightless Dromeosaurids
!FO = Ornithomimids (flightless)
FE = Esperornithes (flying)
FAE = Aquatic Esperornithes (flying)
FH = Hesperornithes (flying)
!FH = Flightless Hesperornithes
FMAB = Flying Modern Aquatic Birds
!FMB = Flightless Modern Birds
FE(other) = Other members of flying hesperornithes (other bird lineages)
MB(other) = Other members of modern flying birds (other bird lineages)
A few notes:
-Now your theory requires both ornithomimids AND flightless dromeosaurids diverging from flying dromeosaurids (flightless dromeosaurids most definitely exist- see most families of dromeosaurids, and remember your claims about Mahakala)
-Aquatic characters in the aquatic bird line need to appear in the enantiornithes stage, creating another divergence (aquatic morphology cannot appear sooner in the flying dromeosaurid stage, since you have the same examples -Microraptor and Rahonavis) at the start for both aquatic and flightless lineages)
-Whether some of hesperornithes could fly or not, since SOME hesperornithes definitely WERE flightless, you have another divergence to secondary flightlessness at a later stage.
Again: am I representing your lineages wrong, and if so, where and how exactly?
A Nonny Mouse posted:
ReplyDelete"It does not name the species. No individual species is listed. It is looking at the higher level phylogeny. But it is implicit in the diagram and all like it."
So for example, looking at the diagram you are saying that at around 104 mya there was a single species of creature that had all the characteristics of modern birds.
Is that right?
http://upload.wikimedia.org/wikipedia/commons/f/f3/Neornithes.jpg
Harry Seeley posted:
ReplyDelete"Hesperornis was not "flying" under the water. It was foot-propelled, not wing propelled."
I get a kick out of someone who can with such confidence say something that he has no idea if it is actually true or not.
And do not forget that foot propelled modern birds use their wings.
The fact that Hesperornis was foot propelled simply adds to the conclusion that like modern birds they also used their wings".
I get a kick out of someone who realizes he was wrong, and tries to patch it up by backpedaling and attacking his opponents.
You wondered, not how Hesperornis "used its wings", but how it could "FLY UNDER THE WATER".
You were wrong. Hesperornis did not "fly" under the water. Only wing-propelled birds do that.
Going off on a tangent about how "foot-propelled birds use wings too" is pointless: Of course they use them, for FLYING. But foot-propelled birds usually keep their wings close to their body when diving, to maintain a hydrodynamic shape.
Here are some pictures of Grebes, loons and cormorants diving:
http://www.youtube.com/watch?v=iQya_S0oFx8
http://www.youtube.com/watch?v=ZIOTp8b1b2U
www.youtube.com/watch?v=FQme1IrGlEU
www.youtube.com/watch?v=QOXMfe2SAWA
www.youtube.com/watch?v=vDG_e2IgrFc
Do you see them using their wings to "fly underwater"?
You were wrong about that. Accept it and move on.
BTW, YBM 1206 has a humerus indeed:
ReplyDeletehttp://home.comcast.net/~eoraptor/Ornithuromorpha.htm
"(YPM 1206) skull (257 mm), mandible (257 mm), teeth, third cervical vertebra (24 mm), fourth cervical vertebra (26 mm), fifth cervical vertebra (28 mm), sixth cervical vertebra (31 mm), seventh cervical vertebra (32 mm), eighth cervical vertebra (33 mm), ninth cervical vertebra (32.5 mm), tenth cervical vertebra (32 mm), three cervicals ribs (37, 83 mm), fourth dorsal vertebra, sixth dorsal vertebra (25.5 mm), six dorsal ribs (145, 172, 190, 209 mm), six uncinate processes (25, 54, 52, 55, 50, 30 mm), synsacrum (320 mm- first sacral 21 mm), first caudal vertebra (19 mm), second caudal vertebra (15 mm), scapula, coracoid (54 mm), clavicle (78 mm), sternum (~200 mm), five incomplete sternal ribs (110 mm), HUMERUS (152 mm), ilium (380 mm), pubis (330 mm), ischium (260 mm), femur (96 mm), tarsometatarsus (132 mm), proximal phalanx II-1, phalanx IV-1 (42.5 mm), phalanx IV-2 (40 mm), phalanx IV-3 (41 mm) (Marsh, 1875)"
Caps mine. Happy now?
Thank you, Harry Seeley. You are right.
ReplyDeleteI have posted all your videos on the site here:
http://pterosaurnet.blogspot.com/2011/10/aquatic-birds.html
They are good videos.
Thank you Harry Seely for the link:
ReplyDeletehttp://home.comcast.net/~eoraptor/Ornithuromorpha.htm
That is exactly what I was looking for.
So that shows that of the Hesperornis that have been found, that 3 have a bone labeled humerus. It looks like one bone labeled humerus per fossil.
And the 3 fossils are from over 100 years ago.
There is still something wrong with this picture.
But it is not essential for my proposed lineage from Hesperornithes to modern birds to prove that Hesperornis flew.
A Nonny Mouse posted:
ReplyDelete"But when they meet they meet in a single species that was the last common ancestor of the two groups."
"It does not name the species. No individual species is listed. It is looking at the higher level phylogeny. But it is implicit in the diagram and all like it."
So for example, looking at the diagram you are saying that at around 104 mya there was a single species of creature that had all the characteristics of modern birds.
Is that right?
http://upload.wikimedia.org/wikipedia/commons/f/f3/Neornithes.jpg
Anyone can contribute on this question.
"So for example, looking at the diagram you are saying that at around 104 mya there was a single species of creature that had all the characteristics of modern birds.
ReplyDeleteIs that right?"
I do not know where that diagram sources its dates from. It may not be entirely accurate. However, whenever it turns out this date should be, I expect there were several species that had all the characteristics of Neornithes, and Neognathae. Characters such as those that I list above. I do not think that you would have been able to place any of them within any particular lineage within the neornithines however. Only one of these would be ancestral to the living Neognathae.
I'm not aware of any fossils that we can point to as filling this gap in our knowledge. But then bird fossils are pretty rare. Given how small and fragile Hesperornis' humerus was compared to its legs or vertebrae its gratifying to see that three are known. (And of course you only need one side of an animal like that anyway- birds are bilaterally symmetrical.)
"So that shows that of the Hesperornis that have been found, that 3 have a bone labeled humerus. It looks like one bone labeled humerus per fossil.
And the 3 fossils are from over 100 years ago."
So? Archaeopteryx has just celebrated its 150th birthday. They're still discovering things about it as new techniques are invented.
"But it is not essential for my proposed lineage from Hesperornithes to modern birds to prove that Hesperornis flew."
Then why are you so insistent that it did? Could it be that it would mean that it was a sister taxon of grebes rather than an ancestor?
"However, whenever it turns out this date should be, I expect there were several species that had all the characteristics of Neornithes, and Neognathae."
ReplyDeleteDo you mean that there were several through convergent evolution?
I thought the idea was that it was a SINGLE species.
Are you backing off the single species idea and going to convergent evolution?
No. There's a difference between the Last Common Ancestor of the living Neognathae, and the point at which characters that define the neognathans appear. Neognathae is usually defined as being the LCA of ducks and doves and all of its descendants (I know you hate cladistics, but bear with me, it is probably the easiest way of explaining things. I'm not aware of any Evolutionary systematics definition that disagrees with this, if you are cite it please). This LCA will share an LCA with the Palagnathae (ratites & tinamous). Between the LCA of Palaeognathae and Neognathae and the LCA of the Neognathae subgroups there will be the "stem neognathans" species closer to living neognaths than to palaeognaths, but which cannot be placed into any living group. As you look at the lineage you will see it evolve the unique characters that today define the neognaths. You'll also see species that left no living descendants split off. At some point you'll have a bird which has all the characters we only see in the neognathans. If you were basing your definition of Neognathae on the first appearance of a suite of characters this would be the first neognathan. But it is not necessarily the LCA of the living ones- it will give rise to more species, most of which will die out without leaving any living ancestors. Some may give rise to a lineage which could persist for a long time afterwards, but ultimately dying out. (Mahakala would be an example of a "basal" member of a group surviving for a long time- and you could cite almost any other "living fossil" as an example). One species did not, and its descendants proliferated.
ReplyDeleteAt the point at which the deep splits in modern birds occurred I expect there were several species that all looked very similar any one of which could have been the LCA of all living birds, but only one of which was. All of these species had those characters previously mentioned. This family then shared a common ancestor which lived a little earlier and would also have had all the characters seen in Neognathans. This ancestor would have been descended from another animal which would have had some but not all of the characters that diagnose the Neognathae. It would have had the descendant which eventually gave rise to the neognathans, but would have had descendants which did not, and, even if we were able to recognise ancestor-descendant relationships in the fossil record, would appear as successive sister taxa to neognathans.
"Turnadout I have already had a long unpleasant discussion about Pagel's study with people who like you wanted to pretend that the study is not saying what it obviously is saying.
ReplyDeleteI am not interested in another argument.
My point is that cladistics includes some buried assumption"
You have grossly misread my paper and seemingly do not understand what my study states. If you would like to discuss this further, please feel free me to email me at the address I have provided.
I am wary of the kind of chicanery that people routinely use - pretending to be someone they are not.
ReplyDeleteI have posted the post but I am leaving it at that.
If the poster presenting himself as Mr. Pagel wishes to enter into discussion here you are certainly invited.
For what it is worth this phrase "grossly misread" is a favorite of the scammers.
ReplyDelete"I know you hate cladistics, but bear with me, it is probably the easiest way of explaining things.".
ReplyDeleteIt is not a matter of "hate".
Cladistics is misconceived.
If you cannot present your position in straightforward ancestor descendant terms then you have already admitted that your argument only stands up under one particular way of looking at it.
And that it cannot stand up under ordinary ancestor descendant concepts.
Is there anyone here who wants to claim that their purported bird lineage depends on all the bird characteristics appearing in ONE SINGLE species - and then all modern birds stemming from that one species.
ReplyDeleteIf so explain to us how that one bird came to have all the characteristics using basic ancestor, descendant terms.
And is there any evidence at all, anywhere of that COMPLETELY MODERN BIRD species (with all the modern bird characteristics) being around 104 mya.
ReplyDelete"Cladistics is misconceived."
ReplyDeleteThere is nothing "misconcieved" about cladistics. It defines groups according to descent and common ancestry. It merely does not allow you to put an official name to a group that does not arbitrarily remove certain descendants of a clade comprised of two taxa their LCA and all of its descendants, or of a similar clade comprised of everything that is more closely related to taxon X than taxon Y. Regardless of how different in physical appearance they may be. Ancestry and descent are deeply involved in cladistics when applied to living animals.
But you can apply cladistics to inanimate objects too.
"If you cannot present your position in straightforward ancestor descendant terms then you have already admitted that your argument only stands up under one particular way of looking at it."
Wrong. My point was that I was using a cladistic definition of "Neognathae". And I did present my arguments in "straightforward ancestor descendant terms". However the fossil record is not straightforward. We have no way of recognising such relationships in the fossil record when we are dealing with tiny sample sizes spread over large periods of time and space, and where there may have been many very similar species all inhabiting an area. One of them may be preserved. Perhaps none of the others were. How do you know that this species was ancestral, and another near-identical one was not? Or indeed if neither was and a third species that we have no record of was the ancestor?
"There is a problem for those who want to claim that their purported bird lineage depends on all the bird characteristics appearing in ONE SINGLE species - and then all modern birds stemming from that one species."
Wrong again. Did you read what I wrote? I emphatically did not say that. The characters gradually accumulate through time in whole series of different species each one descended from the last. Re-read what I wrote.
"It merely does not allow you to put an official name to a group that does not arbitrarily remove certain descendants of a clade comprised of two taxa their LCA and all of its descendants, or of a similar clade comprised of everything that is more closely related to taxon X than taxon Y."
ReplyDeleteYou do not understand the philosophical differences between cladistics and evolutionary systematics.
You have memorized the standard misconceived conception that it is about arbitrarily removing certain descendants of a CLADE comprised of two taxa their LCA and all of its descendants.
Even notice that your criticism itself includes the concept of a clade. As if you can criticize evolutionary systematics using a cladistics idea.
But I have said that there is no point in me trying to straighten you out about this.
Just use standard ancestor descendant evolution ideas. We can both agree on that as being a valid way to analyze this.
I do not know how I can put this in a more fair and straightforward way.
ReplyDeleteIf we do not agree on the use of cladistics, then let us just use basic evolution ideas such as ancestor descendant that we do agree on.
What could possibly be more fair?
Or perhaps you no longer accept the idea of ancestor and descendant. And I do not mean that sarcastically.
ReplyDeleteDo you accept the evolution idea of ancestor and descendant?
That one taxon can evolve into another taxon.
Actually that may be the problem right there.
You no longer accept the idea of one taxon evolving into another.
Again I do not mean that sarcastically.
Molecular clock evidence places the divergence of the Neognathae at 104mya.
ReplyDeleteFossil evidence doesn't entirely support this placing the radiation of modern birds in the Late Cetaceous/Early Eocene. But just because the radiation took place then, doesn't mean that some of the lineages weren't around earlier- the diagram doesn't give any indication of what is happening within the Neoaves. That could be a single family for most of the Cretaceous, or it could have started diversifying at the same time as the ducks and geese split. There is not nearly enough data to say very much.
I am not aware of any fossils of that age. The earliest Neornithine Wikipedia lists is Gallornis which is Hauterivian (140-130mya). Its not entirely clear what Gallornis is- the remains are somewhat scanty. That would indicate that while the splits in the Neornithines may match the molecular evidence the neornithine lineage was distinct further back than that. As Gallornis is not known from much material it is quite possible that while it possessed the modern features seen in the remains known, it didn't have many others and represents a point in the lineage where not all of the Neornithine characters had evolved.
The earliest definite member of the Ornithurae (Neornithes + Ichthyornithiformes + Hesperornithiformes) is Gansus which lived between 115-105mya, and known from excellent material. So while we don't have a completely modern bird, we have something not far off it at this time.
http://en.wikipedia.org/wiki/List_of_fossil_birds#Neornithes
So there are birds that can be tentatively assigned to modern groups (and pretty definitely assigned to Neognathae) 30 million years after the molecular divergence date for Galloanserae and Neoaves. And there are birds that are members of the Neornithes + Ichthyornithiformes + Hesperornithiformes clade 15-20 million years before that, and 40 million years before Hesperornis and co.
By the way, I completely accept the idea of allopatric speciation, peripatric speciation, parapatric speciation and sympatric speciation. So we can talk in those basic evolution terms as well as ancestor and descendant.
ReplyDeletehttp://en.wikipedia.org/wiki/Speciation
"And there are birds that are members of the Neornithes + Ichthyornithiformes + Hesperornithiformes clade 15-20 million years before that, and 40 million years before Hesperornis and co."
ReplyDeleteAgain you have used the idea of a "clade".
Since I consider cladistics to be misguided you have made a statement that is not valid or meaningful.
Can you make your point using standard evolution terms such as ancestor and descendant etc?
Give it a try.
If you cannot present it that way, then there must be a problem with what you are proposing.
And is there any evidence at all, anywhere of that COMPLETELY MODERN BIRD species (with all the modern bird characteristics) being around 104 mya?
ReplyDeleteAnd by the way, for it to be the ancestor of all birds then there would have been HUGE HUGE NUMBERS of this species all over the world. Instead we find a large number of other fossils but we do not find even one of this purported single species.
This just does not pass the most basic test.
I am certainly interested in what A Nonny Mouse has to say about this, but I am also VERY interested in what others have to say about it as well.
ReplyDelete"You do not understand the philosophical differences between cladistics and evolutionary systematics.
ReplyDeleteYou have memorized the standard misconceived conception that it is about arbitrarily removing certain descendants of a CLADE comprised of two taxa their LCA and all of its descendants."
It is arbitrary. You make a decision based on how different you think something is and then remove the group from the other group based on that. That doesn't mean that paraphyletic groups aren't necessarily useful. But they don't describe ancestor descendant relationships very well as you are deliberately removing some of the descendants!
Cladistics also accepts that a group can evolve from another group. But because you're defining a group by its ancestry it does stop being a member of the group that it evolved from just because it looks a bit different.
"Even notice that your criticism itself includes the concept of a clade. As if you can criticize evolutionary systematics using a cladistics idea."
Evolutionary systematics also uses the concept of clades. It just allows them to be paraphyletic. As you know, a clade becomes paraphyletic when you take all the species you decide are different enough, their LCA and all its descendants and remove it from the clade it is a subset of. For the sake of the illustration I was giving above there is no difference between the two classification systems- Neognathans are not a paraphyletic group in any generally accepted classification scheme. Now perhaps you should deal with the actual argument made in that post?
"If we do not agree on the use of cladistics, then let us just use basic evolution ideas such as ancestor descendant that we do agree on."
But evolution is not a straightforward line. It is a branching process. Sooner or later you'll have species that aren't part of an ancestor descendant lineage, but are a sister-taxon to the lineage that continues.
And of course, as repeatedly stated you cannot identify ancestor-descendant relationships in the fossil record. The closest you can get is to say if a species is more closely related to one species than another. You can however refute them- Hesperornis cannot be the ancestor of grebes because it is too specialised.
Do you think that all the species in one family can evolve into another family? Because this is certainly not conventional evolutionary theory.
"Do you accept the evolution idea of ancestor and descendant?
That one taxon can evolve into another taxon."
Yes of course. But this doesn't happen instantly as you seem to think. When one species evolves into another there is a continuum and you cannot say when it has stopped being the old species and started being the new one. You can tell when its definitely happened, but there's a long period where there's a grey area, where hybrids gradually become less and less fertile. Only after this genetic isolation (and much longer periods of time) do you get higher level taxa forming as more and more differences accrue.
If you cannot make your case using standard evolution terms then there is no point in discussion. If you cannot present your ideas in basic evolution terms then there is no way anyone ought to accept it. That is the most basic test.
ReplyDeleteBy the way your idea of the one species giving rise to two new species and so on - I have never read anyone suggesting that.
Is that your own unique idea?
And even more importantly is there any evidence at all of the idea you are presenting?
Why not admit it. There is no way that the lack of fossils can be explained.
There would be HUGE HUGE numbers of this single species.
But I am very used to people not wishing to acknowledge the most obvious thing staring them in the face. The idea of evolution from one single species, that had all the bird characteristics, does not pass the most basic test.
"By the way your idea of the one species giving rise to two new species and so on - I have never read anyone suggesting that."
ReplyDeleteIts basic speciation. You have one species. It splits. You now have two. They diverge. They split again. And so on. Perhaps I have explained myself poorly?
"And even more importantly is there any evidence at all of the idea you are presenting?"
Google for examples of speciation. You'll find many.
"Why not admit it. There is no way that the lack of fossils can be explained.
There would be HUGE HUGE numbers of this single species."
Not at all. If an ameobae splits into two daughter cells and they each split, and so on the number of descendants it have will keep doubling each generation. And yet it started with one individual. One common ancestor. It would be exactly the same with this bird. Each species of modern bird does not evolve from this one single species at the same time. It is the common ancestor of all species.
"But I am very used to people not wishing to acknowledge the most obvious thing staring them in the face. The idea of evolution from one single species, that had all the bird characteristics, does not pass the most basic test."
Actually the most obvious thing staring me in the face is that you've misunderstood what's being said to you.
There was one species of "proto neornithine" it had the characteristics that all later neornithines share. It did not have characteristics that only some neornithines have that means we can say they're parrots rather than pelicans for example. This species gave rise to a lineage, a whole family of species much like it, all but one of which died out and left no living relatives. The species that did leave living relatives split into two. One branch eventually gave rise to the Neognathans, the other the Paleognathans. This species was the LCA of all living birds. Its immediate descendants would have been very similar to each other, and not had all the characters that mean we can distinguish Neognaths from Palaeognaths (apart from ones that are primitive to all birds and have been modified in one or other of these lineages).
The branches also produce new species, and gradually the lineage accumulates the characters that allow us to identify one as being proto-neognaths and one as proto-palaeognaths. All the time species are splitting off, adapting in their own way, giving rise to new species and eventually dying out. At some point on the neognathan line we reach the point where both the branches lead to species that are alive today- one is the ancestor of the Galloanserae, the other the Neoaves. And so it keeps on going, a continuous branching pattern of diversification, evolution and extinction.
Given your fixation on "parallel lines" I am not surprised you have difficulty understanding this concept. You do not understand the philosophical differences between these two worldviews. Perhaps there is no point in me trying to straighten you out about this?