Thursday, October 27, 2011

"Bird feathers are analogous to the wing fibers of pterosaurs,"

Here is a reference that shows the internal composition of the pterosaur wing membrane. It is quite astonishing. Check out page 241 and the pages nearby.

Page 243:
The strings cross the fibres at angles between 30° and 90°

It is astonishing, because we can see that the structure and material of feathers is already present as the actinofibrils in the membrane.
"Bird feathers are analogous to the wing fibers of pterosaurs,"

"Wellnhofer [4, 5] and Padian [6, 7], following von Zittel [8],described a system of fine structural fibers investing the wing membrane, in a pattern similar to the orientation of the feather shafts of birds and the wing fingers of bats, both principal structural elements supporting the patagium and responsible for the transmission of aerodynamic force."
The wing membrane was supported and controlled through a system of stiffened, intercalated fibers, which were oriented like the main structural elements in the wings of birds and bats.

From David Unwin's book "The Pterosaurs from Deep Time":
"...[T]he wing fibers were embedded within the patagia [wing membranes] and typically measured a little less than one-tenth of a millimetre in diameter- about twice the thickness of a human hair. In some spots unravelled fibers reveal that they were composite structures composed of at least 20 or 30 very fine strands, wound together in a helical fashion. Each strand was only a few hundredth of a millimeter across and probably made of collagen a material that is common in the skin of vertebrates".
"The actual function of the actinofibrils is unknown, as is the exact material from which they were made. Depending on their exact composition (keratin, muscle, elastic structures, etc.), they may have been stiffening or strengthening agents in the outer part of the wing.[6] The wing membranes also contained a thin layer of muscle, fibrous tissue, and a unique, complex circulatory system of looping blood vessels.[7]"
"Since they [actinofibrils] were external, they were probably epidermal structures composed of keratin as in scales and feathers."
"research has since shown that the wing membranes of pterosaurs were actually highly complex and dynamic structures suited to an active style of flight. First, the outer wings (from the wing to the elbow) were strengthened by closely spaced fibers called actinofibrils.[5] The actinofibrils themselves consisted of three distinct layers in the wing, forming a crisscross pattern when superimposed on one another."
"The brachiopatagium ("arm membrane") was the primary component of the [pterosaur] wing, stretching from the highly elongated fourth finger of the hand to the hind limbs"

"Pennaceous feathers are also known as contour feathers. This type of feather is present in most modern birds and has been shown in some species of maniraptoran dinosaurs. A pennaceous feather has a stalk or quill. Its basal part, called a calamus, is embedded in the skin. The calamus is hollow and has pith formed from the dry remains of the feather pulp, and the calamus opens below by an inferior umbilicus and above by a superior umbilicus. The stalk above the calamus is a solid rachis having an umbilical groove on its underside. Pennaceous feathers have a central shaft (or rachis) with vanes or vaxillum spreading to either side. These vanes are composed of a high number of flattened barbs, that are connected to one another with barbules.
The barbules are tiny strands that criss-cross on the flattened sides of the barbs. This forms a kind of miniature velcro-like mesh that holds all the barbs together, stabilizing the vanes."
Remiges (from the Latin for "oarsman") are located on the posterior side of the [bird] wing. Ligaments attach the long calami, or quills, firmly to the wing bones, and a thick, strong band of tendinous tissue—known as the postpatagium—helps to hold and support the remiges in place.[1]
" In ornithology, the triangular fold of skin, just back of the shoulder-joint, which runs from the side of the body to the upper posterior face of the upper arm."
"Postpatagium is the tough band of tendinous tissue that envelops and supports the quills of all the wing remiges, from elbow to wingtip. The postpatagium provides much of the elastic strength of the wing and keeps the flight feathers properly aligned and firmly attached to the wing skeleton."

This is interesting:
"I`m not sure exactly how feathers developed,but actinofibrils arranged in a pattern similar to flight feather rachis is very suggestive."

Earlier post:


Tuesday, October 25, 2011

Pterosaur to bird - hand development

The pteroid is composed of two fused phalanges.
The radius, ulna and pteroid bones of FHSM VP-2183. The pteroid bone was once considered to be the 'thumb' (e.g. Digit I) in pterosaurs. The two other pieces of bone in the upper left of the photo are the proximal and distal syncarpals (wrist bones) that would connect to metacarpal IV.
"The wings of many diurnal birds of prey have a vestigial claw located at the end of the thumb bone."

The alula (thumb wing) consists of one phalanx (occasionally two, sometimes even with a nail in some bird species). The alula is present in all birds except the penguins, where it is fused to the carpomatacarpus. It is a freely movable digit with a few small feathers attached. The function of the alula is not yet fully understood. Ornithologists suggest that one function among others is in the landing because it can make a change in the airflow and turbulence along the wing edge. The alula articulates to the carpometacarpus near the wrist.
There has been discussion about whether the alula is really a thumb or an index finger remaining after an evolutionary adaptation. Recent genetic research has shown that the alula is a real thumb and the other two the 'index finger' and 'middle finger'. The outer two fingers are lost (Kaiser 2007).

Arm section

1. Upper arm - humerus
2. Sesamoid bone - os sesamoides.
3. Ulna - ulna
4. Radius - Radius

Hand section (manus)

5. Wrist - radiale and ulnare
6. Metacarpal - carpometacarpus
7. Thumb - alula
8. Digits - phalanges

Sunday, October 16, 2011


The seriemas are the sole extant members of the small and ancient familyCariamidae, which is also the sole surviving family of the Cariamae. Once believed to be related to cranes, they have been placed by one recent study near the falconsparrots and passerines.[1] There are two species:
  • Red-legged Seriema, or Crested CariamaCariama cristata. This is found from eastern Brazil, to central Argentina. It is bigger and nests on the ground or in a bush or tree up to 3 m (9.8 ft) above the ground.
  • Black-legged SeriemaChunga burmeisteri. This is found in northwest Argentina and Paraguay. It nests in a tree.

The seriemas have an extensible second claw that is raised from the ground. This resembles the "sickle claw" of Velociraptor and its relatives.

Friday, October 14, 2011

Paraphyletic = Ancestral
"As late as 2001, Mark Norell and colleagues analyzed a large survey of coelurosaur [maniraptor] fossils and produced the tentative result that dromaeosaurids were most closely related to birds, with troodontids as a more distant outgroup. They even suggested that Dromaeosauridae could be paraphyletic [ancestral] relative to Avialae."

I am quoting this because it sheds light on the word "paraphyletic".
"Paraphyletic" means ANCESTRAL!

It would be a helpful  exercise to substitute the word "ancestral" whenever we see the word "paraphyletic".

There is certainly nothing wrong with being "paraphyletic" since it simply means ANCESTRAL.

Thursday, October 13, 2011


For reference:
"Other authors have questioned the monophyly of the Palaeognathae on various grounds, suggesting that they could be a hodgepodge of unrelated birds that have come to be grouped together because they are coincidentally flightless. One point is that unrelated birds have developed somewhat ratite-like anatomies multiple times around the world through convergent evolution. McDowell (1948)) asserted that the similarities in the palate anatomy of paleognathes might actually be neoteny, or retained embryonic features. He noted that there were other feature of the skull, such as the retention of sutures into adulthood, that were like those of juvenile birds. Thus, perhaps the characteristic palate was actually a frozen stage that many carinate bird embryos passed through during development. The retention of early developmental stages, then, may have been the mechanism by which various birds became flightless and came to look similar to one another.[19]"

Notice that this relates to not just flightlessness, but also the palate:
"Thus, perhaps the characteristic palate was actually a frozen stage that many carinate bird embryos passed through during development. "

Tuesday, October 11, 2011

Origin of flightlessness

This research requires some changes be made to what I have proposed concerning flightless birds. Flightless birds will have to be integrated into multiple lines. For simplicity I had them in one single line.

"Their molecular dating study suggests that the ancestors of the African ostrich, Australasian emu plus cassowary, South American rheas and New Zealand moa became flightless independently, in close association with the extinction of the dinosaurs about 65 million years ago.

"Many of the world's largest flightless birds, known as ratites, were thought to have shared a common flightless ancestor. We followed up on recent uncertainty surrounding this assumption," said Dr Phillips.

"Our study suggests that the flighted ancestors of ratites appear to have been ground-feeding birds that ran well. So the extinction of the dinosaurs likely lifted predation pressures that had previously selected for flight and its necessary constraint, small size. Lifting of this pressure and more abundant foraging opportunities would then have selected for larger size and consequent loss of flight.

The finding of independent origins of flightlessness also solves a mystery of how these flightless birds dispersed across the world over marine barriers -- their ancestors flew."

Friday, October 7, 2011


“We don’t allow faster-than-light neutrinos in here,” says the bartender.
A neutrino walks into a bar.

Organizing the Material

There is a huge amount of material in this blog and it is a challenge to organize it.

I will organize it by type of bird such as those from my Dec 17, 2010 post (which I have updated a bit recently). I will set up a separate thread for each and then add info to each thread.


I will also set up GENERAL threads on common topics. 

Landbirds (Owl)

Landbirds (Owl)
  • Pterosaur (eg. Pterodactylidae/Dsungaripteroidea)  eg. Nemicolopterus -->
  • Enantiornithes landbird subgroup -->
  • Primitive owls,  (eg. Sophiornithidae?--> 
  • Strigiformes (eg. owls), Caprimulgiformes (eg. nighthawks)


Nemicolopterus also demonstrates clear adaptations of the toes and claws for grasping tree branches. Most pterosaurs are known from marine sediments, meaning that they probably caught fish in the ocean and landed on the adjacent beaches or cliffs. Nemicolopterus, on the other hand, is one of just a few known pterosaurs that lived in the continental interior, and probably hunted insects and roosted in the forest canopy.
Sophiornithidae (literally "Wisdom Birds"), was a family of chicken-sized predatory birds that lived from the Paleocene to the Eocene periods of the Cenozoic, and were found primarily in Europe, and are thought to be primitive owls

This chart shows that owls have their own separate lineage (within the landbird branch) which supports what I have proposed concerning owls:

"I wanted to quickly draw attention to a part of the wing that often gets overlooked…..the hair-like [feather-like?] structures along the trailing edge. Kellner et al. 2009 published a small photograph of this

Combs along the trailing edge of the wing (or turbine when we enter the realm of man-made machines) are known to reduce the noise produced by the animal during flight by collapsing the vortex shed off the wing. There is quite a bit of literature on this subject but its function in biological flight could warrant further attention. Owls are certainly the most famous example where these structures are used to reduce the noise produced by the wings

The examples above show just how similar the trailing edge structures of the wing in Jeholopterus (E) are when compared to those of an owl (A, B) and the obvious differences they have with those of a noisy flier, in this case a pigeon (C, D). While I am in no way trying to compare the functionality of a feather with that of the pterosaur membrane, the presence of trailing edge structures would almost certainly function in a similar way to other noise reduction structures.
Jeholopterus shares a couple of similarities with that of the barn owl: they both use a slow flight while hunting and both were active during times of darkness or at least periods of low light, but there the similarities end. Jeholopterus was almost certainly an insectivore rather than hunting small vertebrates and so it is not immediately apparent how effective a noise reducing structure like this would have been (hearing range of insects anyone?). So could Jeholopterus have used its trailing edge structures to break down the vortex shed off its wing? If so it would have flapped and glided over the darkening Mesozoic landscape using a combination of slow flight speed, high maneouverability and specialised fibres to reduce the noise frequency of the wings, snapping up insects as it went. Certainly some food for thought regardless."
"Here we’ll compare Batrachognathus [Anurognathidae pterosaur] with its modern analogs among birds, the swift (Apus apus, Figs. 2) and the nightjar (Caprimulgus), both members of the Apodiformes.""With their stiff, elliptical-tipped, narrow-chord wings, nighthawks remind me of anurognathids."
Perhaps binocular vision has been ignored by pterosaur workers largely because no others have bothered to accurately reconstruct the skulls of the only pterosaurs with substantial binocular vision, the owl-like anurognathids.
Most owls have relatively large, rounded wings. The wings are broad, with a large surface area relative to the weight of the bird i.e. a low wing loading. This allows them to fly buoyantly and effortlessly, without too much flapping and loss of energy. They can glide easily and fly slowly for long periods of time. Many species use this slow flight to hunt ground-dwelling prey from the air. 

Landbirds (General)

  • Landbirds (General)
    • Pterosaur (eg. Pterodactylidae/Dsungaripteroidea) eg. Nemicolopterus -->
    • Enantiornithes landbird subgroups -->
    • Modern landbird groups  (eg. Passerines, Falconiformes etc)


Modern Land Bird

Nemicolopterus also demonstrates clear adaptations of the toes and claws for grasping tree branches. Most pterosaurs are known from marine sediments, meaning that they probably caught fish in the ocean and landed on the adjacent beaches or cliffs. Nemicolopterus, on the other hand, is one of just a few known pterosaurs that lived in the continental interior, and probably hunted insects and roosted in the forest canopy.


  • Pterosaur (eg.  Dsungaripteroidea)  eg. Nemicolopterus -->-->
  • Enantiornithes landbird subgroup -->
  • Modern "Galliformes"(eg. Chicken, Turkey, Pheasant, Quail) and Tinamiformes (Tinamou)


Nemicolopterus also demonstrates clear adaptations of the toes and claws for grasping tree branches. Most pterosaurs are known from marine sediments, meaning that they probably caught fish in the ocean and landed on the adjacent beaches or cliffs. Nemicolopterus, on the other hand, is one of just a few known pterosaurs that lived in the continental interior, and probably hunted insects and roosted in the forest canopy.


WATERFOWL (Presbyornithid line)
  • Pterosaur (eg. Pterodactylidae/Ctenochasmatidae ) --->
  • Presbyornithid subgroup--> 
  • Modern Anseriformes (eg. Duck, Geese , Swan)
  • Pterosaur (Ctenochasmatidae) Pterodaustro   --->
  • Presbyornithid subgroup--> 
  • Primitive bird, Palaelodidae (Phoenicopteriformes)  --> 
  • Flamingo (Phoenicopteriformes)
    Presbyornithidae were a family of waterbirds with an apparently global distribution that lived until the Earliest Oligocene, but are now extinct. Initially, they were believed to present a mix of characters shown by waterbirds,shorebirds and flamingos and were used to argue for an evolutionary relationship between these groups (Feduccia 1976), but they are now generally accepted to be "wading ducks", the sister taxon [actually the ancestor] of the Anatidae, and thus essentially modern waterbirds. They were generally long-legged, long-necked birds, standing around one meter high, with the body of a duck, feet similar to a wader but webbed, and a flat duck-like bill adapted for filter feeding.  Apparently, at least some species were very social birds that lived in large flocks and nested in colonies.

    As the "wading duck" moniker implies, they were waterfowl whose elongated legs enabled them to live a lifestyle similar to the "proto-flamingos" (e.g., Palaelodus) - which were not really ancestors of the modern flamingos, but a group that evolved in parallel with them and in fact seems to have taken over part of the presbyornithid's ecological niche after the latter became extinct. Thus, while probably somewhat capable of swimming, they would have preferred to strain the shallow waters of their habitat for food and were also able to snatch up insects and small crustaceans on dry land, just like some species of modern ducks, e.g., the Laysan Duck, hunt for brine flies.

    Temporal range: Late Cretaceous? - Oligocene
    Presbyornis is an extinct genus of anseriform bird. It contains two unequivocally accepted species; the well-known P. pervetus and the much lesser-known P. isoniP. pervetus was approximately the size and shape of a goose, but with longer legs; P. isoni, known from a few bones, was much larger, more than swan-sized. Other fossils, more doubtfully assigned to this genus, are also known.
    Judging from numerous fossil findings, Presbyornis is presumed to have lived in colonies around shallow lakes. Its broad, flat bill was used to filter food (small plants and animals) from the water, in the manner of today's dabbling ducks.[3]
    "Fowl were the first neognath lineages to evolve. From the limitedfossils that have to date been recovered, the conclusion that they were already widespread - the predominant group of modern birds - by end of the Cretaceous is generally accepted nowadays.Fossils such as Vegavis indicate that essentially modern waterfowl - albeit belonging to a nowadays extinctlineage - were contemporaries of the (non-avian)dinosaurs.

    It says "albeit belonging to a nowadays extinct lineage". It should say that the Vegavis developed into modern waterfowl.

     is a genus of extinct bird that lived during the Late Cretaceous (Maastrichtian stage) of Antarctica, some 65 mya. It belonged to the clade Anseriformes
    Among modern birds,Vegavis is most closely related to ducks and geese (Anatidae), but it is not considered to be a direct ancestor of them." [However it possibly should be considered a direct ancestor of them].
    The discovery of the type speciesVegavis iaai, demonstrates that the major groups of bird alive today had already diversified in the Cretaceous. This supports the longstanding phylogenetic inferences of paleornithologists.[citation needed] It has been hailed as the first definitive physical proof that representatives of some of the groups of modern birds lived in theMesozoic.[1]"
    "We have more data than ever to propose at least the beginnings of the radiation of all living birds in the Cretaceous," Clarke says. "We now know that duck and chicken relatives coexisted with non-avian dinosaurs. This does not mean that today's chicken and duck species lived with non-avian dinosaurs, but that the evolutionary lineages leading to today's chicken and duck species did." (Julia A. Clarke1,2, Claudia P. Tambussi3, Jorge I. Noriega4,
    Gregory M. Erickson5,6,7 & Richard A. Ketcham8)

    Relationships to the waterfowl were considered as well,[3] especially as flamingos and waterfowl are parasitized by feather lice of the genus Anaticola, which are otherwise exclusively found on ducks and geese.[4]

    Pterosaurs lasted till late Cretaceous
    Presbyornithids spanned from late Cretaceous? to Early Oligocene
    Palaelodidae spanned from early Oligocene to Middle Pleistocene
    Modern flamingos span from 30 mya to the present day
    There is evidence to indicate the Flamingo evolved at least 30 million years ago, perhaps longer. 

    "Our investigation of skeletal and ontogenetic variation in Pterodaustro gives insights into the
    developmental growth dynamics of this unusual ctenochasmatid pterodactyloid from early
    ontogeny through to adulthood and also pro vides information pertaining to histological variability within and between bones of individuals. This study also documents the presence of what appears to be medullary bone tissue within the medullary cavity of a large femur of Pterodaustro. This  suggests that,  like  birds,  reproductively  active female  pterosaurs  may have deposited a special bone tissue (medullary bone) to cope with  the demand of  calcium  during  eggshelling."