Alan Feduccia and others have championed the "temporal paradox".
http://en.wikipedia.org/wiki/Temporal_paradox_%28paleontology%29
"The concept of a "temporal paradox" is based on the following facts. The consensus view is that birds evolved from dinosaurs, but the most bird-like dinosaurs, including almost all of the feathered dinosaurs and those believed to be most closely related to birds (the maniraptorans), are known mostly from the Cretaceous, by which time birds had already evolved and diversified. If bird-like dinosaurs are the ancestors of birds they should be older than birds, but Archaeopteryx is 155 million years old, while the very bird-like Deinonychus is 35 million years younger. This idea is sometimes summarized as "you can't be your own grandmother". "
The problem with this criticism of the dino-to-bird idea is that the argument is misguided. It is based on the incorrect idea that the feathered creatures such as the Dromaeosaurs were dinosaurs. As this site has shown, they were not dinosaurs. They were birds.
So the "temporal paradox" argument is neither correct nor incorrect. It is just misguided.
Note: For those interested in an additional supporting reference, see page 6 of this article from Stephen Czerkas:
http://www.dinosaur-museum.org/featheredinosaurs/Are_Birds_Really_Dinosaurs.pdf
"Decades of scientific debates were based on the mistaken identity of regarding dromaeosaurs as dinosaurs instead of the birds that they really are."
Archaeopteryx being before Deinonychus doesn't mean that a dinosaurian origin for birds isn't possible. First; there are many recently (and not so recently) discovered maniraptorans that predate Archaeopteryx (Epidexipteryx, Scansoriopteryx, Anchiornis, Pedopenna, Praeornis), are contemporaneous with it ("the Guimarota Archaeopteryx") or just slightly younger than it (Koparion, Palaeopteryx, "Lori"), as well as many maniraptoran-like teeth from the mid to late Jurassic. Second; ghost lineages exist (Choristoderans, Tardigrades, Coelocanths, Priapulids, Australosphenids(?), etc.), , and they don't disprove anything. As someone interested in pterosaurs, you should know that most organisms, especially small, flying organisms with fragile bones, do not fossilize. Because of this, there are bound to be gaps in the fossil record. Also, when a group isn't particularly diverse or common (usually towards its origin or decline), it isn't likely to be preserved (Signor-Lipps law). There are also pterosaur ghost lineages (Anurognathidae for one). Third, the proposed alternative proto-birds either aren't even archosaurs (Longisquama, Drepanosauridae, etc.), or simply chimeric (Protoavis). To summarize what I have just written, the temporal paradox argument (and the BCF hypothesis) is incorrect and misguided. Fourth: if you define aves as the common ancestor of Archaeopteryx lithographica and Gallus gallus, and if Archaeopteryx is a Deinonychosaur, then domaeosaurs are birds, but that's not really relevant. Fifth; Bakker's definition of Dinosauria is synonymous with avemetatarsalia/ornithodira, which would make pterosaurs dinosaurs, and then, either way you look at it, birds are dinosaurs. Sixth; Stephen Czerkas? Really?
ReplyDeleteThe fact is that there were actual flying birds (eg. dromaeosaurs) at the time of the very earliest dinosaurs. Birds did not and could not have developed from dinosaurs since they co-existed right from the beginning.
ReplyDeletehttp://www.dinosaur-museum.org/featheredinosaurs/Are_Birds_Really_Dinosaurs.pdf
ReplyDelete"The irony here is that if there was one thing scientists agreed on, it was that dromaeosaurs were not birds and were only dinosaurs. Many, if not most, ornithologists thought that the bird-like characteristics found in dromaeosaurs were only convergent, perhaps brought about by similar behavior, but not due to
having a direct ancestry. Opposing this view were paleontologists who believed dromaeosaurs were non-avian dinosaurs that were evolving towards becoming true birds. For either view to be maintained, dromaeosaurs could not be birds because that would essentially nullify the arguments from either side.
Decades of scientific debates were based on the mistaken identity of regarding dromaeosaurs as dinosaurs instead of the birds that they really are. With the benefit of hindsight it is easy to see that if fossils of the small flying dromaeosaurs from China had only been discovered before the larger flightless dromaeosaurs like Deinonychus or Velociraptor were found, the interpretations of the past three decades on how birds are related to dinosaurs would have been significantly different. If it had already been established that dromaeosaurs were birds that could fly, then the most logical interpretation of larger flightless dromaeosaurs found afterwards would have to be that they represented birds, basically like the prehistoric equivalent of an Ostrich, which had lost their ability to fly.
Only about a year later did reporters finally acknowledge that these dromaeosaurs could fly. The discovery had been verified by yet more fossils of similar dromaeosaurs, called Microraptor, from China. However, instead of acknowledging these dromaeosaurs as birds, scientists now called them “flying dinosaurs.”
This misguiding ploy of semantic double-talk was used to hide the fact that reputations based on the theory of birds evolving from ground dwelling dinosaurs were at stake. Even though dromaeosaurs had previously been vehemently denied as being birds or having flight feathers and the ability to fly, all this
was swept aside as if there was no conflict in now regarding dromaeosaurs as flying dinosaurs. In part, this was made possible because not only did these flying dromaeosaurs have two wings like flying birds, but their hind legs were also equipped with long flight feathers giving the appearance of having four wings. With a complete disregard that these dromaeosaurs were not supposed to have any wings or ability to fly, the surprising hind wings were used to distract from the obvious implications that this still meant scientists were wrong in portraying dromaeosaurs as the ground dwelling non-avian ancestors of birds. Dromaeosaurs were birds, but in order to maintain the theory of how birds supposedly evolved from ground dwelling dinosaurs, no one could admit it."
Yes, Deinonychosaurs could be birds, depending on where they fit cladistically, and what your definition of "bird" (Aves/Avialae, etc.) is, but they still have much more in common with other dinosaurs than pterosaurs. Also, Stephen Czerkas doesn't even have a university degree. I'm not saying that this alone makes him a bad scientist, but the Archaeoraptor scandal, and naming three genera for one animal (Didactylornis, Sapeornis, Omivoropteryx), don't to much to help his reputation either.
ReplyDeleteYou say they "still have much more in common with other dinosaurs than pterosaurs".
ReplyDeleteThis is not correct.
First the maniraptors are not "other dinosaurs" because they are not dinosaurs. You are slipping in your bias.
Second, this entire website shows that maniraptors are more closely related to pterosaurs than they are to dinosaurs.
Third concerning Czerkas, let me say this.
It is a common tactic of the dino to bird theory people to attack the researcher rather than the facts.
I am interested in the facts.
No you are not, you are only interested in promoting your own hypothesis. Also "this is not correct" isn't really a good counterpoint to anything, especially when debating something scientific. You could have at least built on it with some details of anatomy or quoted someone, but you say I am "slipping on my bias" (What?!?!?!), and then cite your very own website, again.
ReplyDeleteSecond; I didn't "attack" Czerkas, I just meant that he's not very good at taxonomy. He's certainly good at other things (curating, administrating, etc.).
You have said:
ReplyDelete"You could have at least built on it with some details of anatomy or quoted someone,"
I have outlined numerous aspects of anatomy and quoted researchers in the field, over the course of hundreds of posts.
Why are you using up your time commenting here if you are not willing to go into the kind of detail I have gone into?
Because this is your blog.
ReplyDeleteTell you what. When you are willing to make an effort I will make an effort to respond.
ReplyDeleteI meant that you, not I, should go into more detail, because nothing on your blog is the least bit convincing.
ReplyDeleteThat is your opinion.
ReplyDeleteWhen you are willing to make an effort I will make an effort to respond.
"The fact is that there were actual flying birds (eg. dromaeosaurs) at the time of the very earliest dinosaurs. Birds did not and could not have developed from dinosaurs since they co-existed right from the beginning."
ReplyDeletethe very earliest dinosaurs appear in the late triassic, while the first unambiguous dromaeosaurs appear in the early cretaceous, and even if the supposed jurassic dromaeosaurs really are dromaeosaurs (and by the way palaeopteryx is a way better candidate for jurassic dromaeosaur than the russian teeth), that still leaves a pretty big gap between the earliest dinosaurs and the earliest dromaeosaurs. Please explain how what you said made any sense.
The current dino to bird theory claims that birds evolved from coelurosaur dinosaurs. Coelurosaurs stem from the mid-Jurassic.
ReplyDeleteSee:
http://en.wikipedia.org/wiki/Coelurosauria
Yes, but coelurosaurs are descended from more basal tetanurans, which date back to the early jurassic. Tetanurans are descended from more basal theropods, which date back to the late triassic, etc. What is your point?
ReplyDeleteDjango, think about it.
ReplyDeleteI am not using up my time responding at any length to your pretending not to get what I am saying.
Pretending not to understand what you're saying? Right now, I really have no idea what your point is.
ReplyDelete"The current dino to bird theory claims that birds evolved from coelurosaur dinosaurs. Coelurosaurs stem from the mid-Jurassic."
You've said that members of maniraptoriformes are not dinosaurs. These earliest coelurosaurs are basal tyrannosauroids like proceratosaurus (the earliest known unambiguous coelurosaur), guanlong, and kileskus, as well as haplocheirus, which, as a basal alvarezsauroid, is a member of maniraptoriformes, also, it doesn't have a backwards pointing pubis, like all alvarezsauroids and ornithomimosaurs, as well as the aforementioned taxa. Seriously, what is your point?
The underlying problem is that in cladistics the category "coelurosaur" includes maniraptors.
ReplyDeleteBy coelurosaur I mean the non-maniraptor dinosaurs.
That is why the terminology of Senter (2010)
is so helpful.
Senter:
"Tyrannosaur cluster"
"Birdlike cluster"
Use these categories and restate your question, if you would like me to work with you on this.
Tyrannosaur cluster=Tyrannosauroidea
ReplyDeleteBirdlike cluster=Maniraptoriformes
there are coelurosaurs other than these though (zuolong, etc.), so I don't really see how this is any more helpful than the existing classification of coelurosauria, other than simplifying the names.
Stop evading the question and give a straight answer, what is your point?
You did not restate your earlier post using the Senter categories as I had requested.
ReplyDeleteHere is what you said that needs to be restated using the Senter categories:
"You've said that members of maniraptoriformes are not dinosaurs. These earliest coelurosaurs are basal tyrannosauroids like proceratosaurus (the earliest known unambiguous coelurosaur), guanlong, and kileskus, as well as haplocheirus, which, as a basal alvarezsauroid, is a member of maniraptoriformes, also, it doesn't have a backwards pointing pubis, like all alvarezsauroids and ornithomimosaurs, as well as the aforementioned taxa."
By the way, in order to understand the Senter categories you will need to look at the Senter material. There is a fair amount of it on the site.
ReplyDeleteYou can use the search function to find it.
To begin with, you will need to see exactly which groups are included in those categories.
I just told you, the Tyrannosaur cluster is synonymous with Tyrannosauroidea, and the
ReplyDeleteBirdlike cluster is synonymous with Maniraptoriformes, I haven't read the material, but from what you have said I'm pretty sure that's what he meant, if you could provide a link, that would be great.
These two sister taxa, along with some more basal forms like Zuolong, etc. form
Coelurosauria. Coelurosauria as defined by Sereno, includes all organisms closer to Passer domesicus than they are to Allosaurus fragilis. So if you apply this definition to your "theory", Coelurosauria a junior synonym of Pterosauria, but since your Pterosauria isn't defined using cladistics, it really doesn't matter.
Anyway, here's what I said with the Senter categories added in:
"The current dino to bird theory claims that birds evolved from coelurosaur dinosaurs. Coelurosaurs stem from the mid-Jurassic."
You've said that members of [the birdlike cluster] are not dinosaurs. These earliest coelurosaurs are basal [members of the Tyrannosaur cluster] like proceratosaurus (the earliest known unambiguous coelurosaur), guanlong, and kileskus, as well as haplocheirus, which, as a basal alvarezsauroid, is a member of [the birdlike cluster], also, it doesn't have a backwards pointing pubis, like all alvarezsauroids and ornithomimosaurs, as well as the aforementioned taxa. Seriously, what is your point?
It's not really much different. Again, seriously, what is your point?
Use the search function on the site to look up Senter references.
ReplyDeleteI thought you had read the site. But if not, now is a good time to start.
I am not using up my time with you, till you have read what I have taken months to post.
I read the abstract, but it wants me to register to read it in its entirety. First of all, it supports the theory that birds are dinosaurs. Second, it simplifies terms like I already mentioned. How does this support your theory? How is it contradictory to what I said?
ReplyDeleteYou do know that there are plenty of free papers on subjects like these online, right?
You should check this out:
http://home.comcast.net/~theropod-archives/
SENTER (2010):
ReplyDelete"Birdlike cluster" according to Senter:
Dromaeosauridae (dark blue): 25, 26, 27, 28, 29
Troodontidae (light blue): 23, 24
Aves (violet): 31, 32, 33
Protarchaeopteryx + Incisivosaurus (light green): 17
Epidendrosaurus + Epidexipteryx (magenta): 30
And Senter says these are a morphologically continuous group.
Turning to the "Tyrannosaur cluster", Senter includes:
Tyrannosauroidea (pink): 4, 5, 6
Compsognathidae (red): 7, 8, 9
Ornitholestes (orange): 10
And Senter says these are a morphologically continuous group.
For reference:
http://www.tiede.fi/keskustelut/evoluutio-ja-fossiilit-f8/coelurosaurien-baraminologiaa-t47129.html?p=1391425
Django, did you use the search function on the site to look up the Senter references on the site?
ReplyDeleteThere is a search box on the right side of every page.
The point I have made is:
ReplyDeleteThe fact is that there were actual flying birds (eg. flying dromaeosaurs) at the time of the very earliest coelurosaur dinosaurs (THE TYRANNOSAUR CLUSTER). Birds did not and could not have developed from coelurosaur dinosaurs (THE TYRANNOSAUR CLUSTER) since they co-existed right from the beginning.
The significant thing about the Senter clusters is that they are not based on cladistics.
ReplyDeleteThey are based on actual facts about the creatures.
For details see:
ReplyDeletehttp://pterosaurnet.blogspot.com/2010/08/clusters.html
The Senter clusters are based on actual facts about the creatures.
ReplyDeleteIn cladistics, actual facts about the creatures are also used.
But (and it is a big BUT) in cladistics the assumption of phylogeny is built right into the vocabulary and categorization.
For example in cladistics, birds are called coelurosaurs. This is building into the vocabulary the assumption that birds are descended from coelurosaur dinosaurs.
And that is the idea that needs to be challenged - and not built right into the vocabulary!
Yes, but the Senter clusters are (mostly) synonymous with the taxa I already mentioned, even if they aren't based on cladistics. They aren't meant to be real taxa, but morphological groupings, which even he found to be very similar, you seem to have misinterpreted what he said. Compsognathidae may be paraphyletic, and many of them may be Tyrannosauroids (Aristosuchus, Mirischia, Calamosaurus, etc.), the placement of Ornitholestes within Coelurosauria fluctuates, but many recent cladistic analyses place it as a basal member of Maniraptoriformes, along with Scipionyx and most of the remaining Compsognathids (Huaxiagnathus, Sinocalliopteryx, Sinosauropteryx, Compsognathus, and Juravenator, which might be a juvenile Compsognathus). Since Proceratosaurus is a tyrannosauroid, and thus a member of the Tyrannosar cluster, as well as being the earliest known Coelurosaur, the Tyrannosaur cluster predates the Birdlike cluster. Also, the age of these groups isn't incredibly important, as many recent finds (Guanlong, Haplocheirus, Anchiornis, Kileskus, etc.), as well as re-evaluation of previously known taxa like Proceratosaurus have extended these groups that were previously only known from the Cretaceous back to the mid and late Jurassic, making the "temporal paradox" obsolete, since these finds have shown that significant ghost lineages existed in these groups.
ReplyDeleteBirds were only considered Coelurosaurs after cladistic analyses found them to be members of this group, and that idea has been challenged, unsuccessfully.
Django, according to the wikipedia article Proceratosaurus goes back to 165 mya.
ReplyDeletehttp://en.wikipedia.org/wiki/Proceratosaurus
According to th wikipedia article dromaeosarids go back to 167 mya.
http://en.wikipedia.org/wiki/Dromaeosauridae
Why are you still arguing about this?
As I said:
The fact is that there were actual flying birds (eg. flying dromaeosaurs) at the time of the very earliest coelurosaur dinosaurs (THE TYRANNOSAUR CLUSTER). Birds did not and could not have developed from coelurosaur dinosaurs (THE TYRANNOSAUR CLUSTER) since they co-existed right from the beginning.
I know it is hard for you to acknowledge, but those are the facts.
Birds could not have evolved from coelurosaur dinosaurs (ie. they could not have evolved from the tyrannosaur cluster).
When you realize this, you realize you need to look for an alternative. That alternative is pterosaurs.
By the way, if you want to speculate about ghost lineages, then we can also speculate about ghost lineages of flying dromaeosaurs going back to the mid Jurassic.
ReplyDeleteI prefer to work from facts, rather than speculation.
"According to th wikipedia article dromaeosarids go back to 167 mya."
ReplyDeleteAs I have already said, the unnamed unit in which the teeth were found dates back to the late bathonian which would make it about 164 million years old, the wikipedia uses the earliest extent of the bathonian, and the teeth could also be some other kind of paravian.
"By the way, if you want to speculate about ghost lineages, then we can also speculate about ghost lineages of flying dromaeosaurs going back to the mid Jurassic.
I prefer to work from facts, rather than speculation."
That wouldn't be surprising, there are already other paravians known from that time period, what I'm saying are that there aren't any unambiguous dromaeosaur(id) remains dating back to this time period. It also wouldn't be surprising, because the fossil record for dinosaurs in the mid jurassic is very poor, and only recently have many dinosaur clades been discovered to date back to this time period. You prefer to work from facts rather than just speculate? Then what is this?
"'By the early Cretaceous, some other pterosaurs (by the process of cladogenesis), had developed into flying enantiornithes.
And by the late Cretaceous, many of these flying enantiornithes had developed into a variety of modern flying birds (Neognaths).
Concurrently, during the Cretaceous, some of the flying enantiornithes settled on the land/water, and developed (by the process of cladogenesis), into primitive aquatic birds, such as the hesperornithes.
And by the Paleocene, these primitive aquatic birds had developed into modern aquatic birds, such as loons, grebes and penguins.'
All of this follows the same types of processes analyzed earlier, related to dromaeosaurids etc.
Note, that because dromaeosaurids and troodontids developed from pterosaurs by cladogenesis, there were still pterosaurs extant, so the cladogenesis of enantionithes from pterosaurs, could also occur, during the Cretaceous."
How is that not speculation?
"I know it is hard for you to acknowledge, but those are the facts.
Birds could not have evolved from coelurosaur dinosaurs (ie. they could not have evolved from the tyrannosaur cluster).
When you realize this, you realize you need to look for an alternative. That alternative is pterosaurs."
If you look at the actual study, you'd see that Senter means almost the exact opposite of what you mean. Also, there have been so many other crazy alternatives to the currently accepted theory of bird origins; birds evolved from mammals/basal synapsids/mammals are sister group of birds (the haematotherm theory, birds evolved directly from flying fish, birds evolved from "sphenosuchians", birds evolved from basal diapsids/archosauromorphs (things like sharovipteryx, longisquama, melangcosaurus,etc.),etc. How is your theory any better? Even if you were able to disprove that birds evolved from dinosaurs, that wouldn't automatically make your theory, as there are so many equally bad theories. As I have already said this isn't an "if not A then B" kind of deal.
Senter does not mean the opposite, but I am not continuing to argue with you about that.
ReplyDeleteIf you have a better alternative than pterosaurs, please feel free to spend years of study on it, as I have done, and prepare a site outlining it, as I have done.
If you wish to explore the pterosaur idea further with an open mind, I am here.