New opinions ...

“New opinions are always suspected, and usually opposed, without any other reason but because they are not already common."
~John Locke

"In the choice between changing one's mind and proving there's no need to do so, most people get busy on the proof."
~John Kenneth Galbraith

"Our wretched species is so made that those who walk on the well-trodden path always throw stones at those who are showing a new road."
~Voltaire

"You have enemies?  Good.  That means you've stood up for something, sometime in your life."
~Winston Churchill

What is the alternative?

http://www.jstor.org/pss/4085810
According to this reference, for a long time, folks thought that birds evolved from "pseudosuchian archosaurs". Then that fell from favour and was replaced by a purported "direct derivation of birds from theropod dinosaurs". 


When that was shown to be untenable, some folks moved to the idea that birds evolved from crocodile type ancestors. (Yes, crocodiles). 
But then that idea fell from favour and the folks moved to some purported vague dinosaur ancestry. But they do not give any specifics so that it can never be evaluated. 
Perhaps someone could do us all a favour and tell us what the current thinking is about the purported dino to bird lineage.

I have proposed a lineage. What is the alternative? 

Pterosaur teeth are like bird teeth

Pterosaur teeth:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAHLEntit9Gt4iqsjZqcfoT5IHjB8ISKCbqCaIAJ2dy7x8YMypjw1ZzUHBCmP2o4M5N2l2mz0yfn18o2UPg9LWsksWrSycP0h2bXKDVyQXDteu9VeotuTJYb6M-xLtPjYQxPgZrAD3pld9/s400/PterosaurTeeth.jpg

Here is a theropod dinosaur tooth:

http://australianmuseum.net.au/image/Theropod-dinosaur-tooth/
"SEM of theropod dinosaur tooth, showing serrated edge."

http://www.palaeodiversity.org/pdf/03/Palaeodiversity_Bd3_Nesbitt.pdf

The presence of an external mandibular fenestra, along with morphological evidence elsewhere in the body of pterosaurs (serrated teeth, antorbital fossa present, fourth trochanter on the femur present), supports a placement of Pterosauria within Archosauriformes and is consistent with a position within Archosauria.

https://pterosaurheresies.wordpress.com/2011/08/30/the-truth-about-toothless-pterosaurs/

In several pterosaurs the medial or first premaxillary tooth was procumbent
[excessive inclination of the incisor teeth toward the lips]. It angled forward as well as downward. In B St 1967 I 276 (No. 6 of Wellnhofer 1970), the tiniest pterosaur, the anterior premaxillary tooth was procumbent. 

 http://en.wikipedia.org/wiki/Deinonychosauria

The teeth of deinonychosaurs were curved and serrated, but not blade-like except in some advanced species such as Dromaeosaurus albertensis. The serrations on the front edge of deinonychosaur teeth were very small and fine, while the back edge had serrations which were very large and hooked.^[3] 

https://en.wikipedia.org/wiki/Oviraptorosauria

The most primitive members have four pairs of teeth in the premaxillae, such as in Caudipteryx[9] and in Incisivosaurus they are enlarged and form bizarrely prominent bucktoothed [procumbent] incisors.

http://blogs.scientificamerican.com/tetrapod-zoology/yi-qi-is-neat-but-might-not-have-been-the-black-screaming-dino-dragon-of-death/

The scansoriopterygid skull is short-faced and robust, the anterior end of the lower jaw is slightly downturned, and the teeth are procumbent.

http://en.wikipedia.org/wiki/Yi_(dinosaur)

[Yi qi] Like other scansoriopterygids, the head was short and blunt-snouted, with a downturned lower jaw. Its few teeth were present only in the tips of the jaws, with the four upper front teeth per side being the largest and slightly forward-pointing, and the front lower teeth being angled even more strongly forward.^[1] 

https://en.wikipedia.org/wiki/Oviraptorosauria

The most primitive members have four pairs of teeth in the premaxillae, such as in Caudipteryx^[9] and in Incisivosaurus they are enlarged and form bizarrely prominent bucktoothed incisors

Uniqueness

http://bigcat.fhsu.edu/biology/cbennett/flotsam/Bennett-2008-forelimb-myology.pdf
"...the large size, great length, and unconventional arrangement such that it swung backward in flight position enabled digit IV to spread and support the wing yet fold it out of the way when the animal was not flying.
Such an arrangement of fingers with one swinging away from the others is unique among vertebrates."
Let's consider this "uniqueness".
Whenever an explanation requires a characteristic that is "unique among vertebrates" we have to question whether this explanation is correct. 
After all, if someone says to you - okay here is how it worked. It worked in a way that is found NOWHERE ELSE IN THE VERTEBRATE WORLD. Then you have to think that perhaps that explanation is not correct. 
So I think we can put such an explanation to the side. 

In case people are having trouble visualizing what I am proposing, work with your own hand. 
Hold your hand out, palm down. Your index finger is the wing finger so it is very long. Bend your index finger toward your palm. Now imagine that you could continue bending it in that direction so that the index finger would point back toward the elbow. 
That is what I am suggesting. 
Now the question arises as to how that could be accomplished, given the length of the index finger.
I can see how that could be accomplished but if anyone would like to offer up a suggestion please do.

Here is how it could work:
Begin with the pterosaur on all fours (or standing) with the index finger bent (toward the palm and then toward  the elbow). 
The unfolding of the index finger is a combined motion of lifting the arm, rotating the arm slightly backward (palm back) and unfolding the finger. Then at the top of the arm extension, rotating the arm back again.

What I am saying does not require a vault launch method but it would work with that method as well. 
See video:
http://www.newscientist.com/article/dn19724-did-giant-pterosaurs-vault-aloft-like-vampire-bats.html

A question about the pterosaur wing finger folding

Does this drawing represent the current thinking about how the pterosaur folded its wing finger?

http://pterosaurheresies.files.wordpress.com/2011/10/standing-pteranodon-72.jpg?w=584&h=793

AND

Here is a basic question about the current thinking - that the 4th finger is the wing finger and that it is turned 90 degrees. Is it turned 90 degrees TOWARD the THUMB or 90 degrees AWAY from the THUMB? I have not seen any reference that explicitly answers that question.
Can anyone provide a reference that gives the answer to that question? 

Propatagium

Pterosaur:
http://en.wikipedia.org/wiki/Pterosaur

"The pterosaur wing membrane is divided into three basic units. The first, called the propatagium ("first membrane"), was the forward-most part of the wing and attached between the wrist and shoulder, creating the "leading edge" during flight."


Bird:

http://www.brendanbody.co.uk/flight_tutorial/index.html

"Here is an image of a White Ibis in flight showing full breeding plumage, in this instance the bird is pushing it's wings down and the arm is stretched out. As you can see, we get a good view of where the bones are positioned in the wing, notice that they don't run along the front of the wing. The elbow is set back from the leading edge and the bend in the arm is hidden by the Propatagium, a fold of skin inside the front part of the wing which connects to the shoulder and the wrist."


http://onlinelibrary.wiley.com/doi/10.1002/jmor.1052190209/abstract
"The [bird] propatagium is variably deployed, relative to elbow extension, in flight; support for its cambered shape is maintained by multilayered collagenous and elastic tissue networks suspended between leading edge and dorsal antebrachium." 

Birdman

For fun:
http://www.youtube.com/watch?v=5N9t5qOSzCU&feature=related

Ventilation - pterosaurs are like birds

http://news.sciencemag.org/sciencenow/2009/02/19-02.html

"Modern birds sustain their flight with an efficient ventilation system that keeps air flowing to their muscles. But no one knew how pterosaurs, the first flying vertebrates, powered their wings. A new study in PLoS One concludes that ancient pterosaurs, flying reptiles that lived 220 million to 65 million years ago, did much the same, with a mobile rib cage and a system of air sacs distributed throughout the bones to help move air around."
"The researchers also studied the air spaces in pterosaur bones and concluded that they were associated with air sacs, arranged in patterns similar to those seen in modern birds. The bigger the pterosaur, the more air sacs, just like in modern birds. The air spaces help oxygen circulate and probably also made bones light enough for flight."

Note as always there are dissenting opinions:

"But matching anatomy in pterosaurs to modern animals may be misleading, says Jaap Hillenius, a functional morphologist at the College of Charleston in South Carolina. Pterosaurs left no descendants and are only distantly related to birds. It's possible that the new study is correct, Hillenius says, but he's skeptical. For example, he thinks the model of rib-cage movement doesn't allow enough air for active flight, and that the sternum was not strong enough to support such movement. "Until we find a living pterosaur," there's no way to know for sure—"and that's not going to happen."".

The study itself:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2637988/



https://en.wikipedia.org/wiki/Air_sacs

John Ruben et al. (1997, 1999, 2003, 2004) disputed this and suggested that dinosaurs had a "tidal" respiratory system (in and out) powered by a crocodile-like hepatic piston mechanism – muscles attached mainly to the pubis pull the liver backwards, which makes the lungs expand to inhale; when these muscles relax, the lungs return to their previous size and shape, and the animal exhales. They also presented this as a reason for doubting that birds descended from dinosaurs.[5][6][7][8][9]
Critics have claimed that, without avian air sacs, modest improvements in a few aspects of a modern reptile's circulatory and respiratory systems would enable the reptile to achieve 50% to 70% of the oxygen flow of a mammal of similar size,[10] and that lack of avian air sacs would not prevent the development of endothermy.[11] Very few formal rebuttals have been published in scientific journals of Ruben et al.’s claim that dinosaurs could not have had avian-style air sacs; but one points out that the Sinosauropteryx fossil on which they based much of their argument was severely flattened and therefore it was impossible to tell whether the liver was the right shape to act as part of a hepatic piston mechanism.[12] Some recent papers simply note without further comment that Ruben et al. argued against the presence of air sacs in dinosaurs.[13]

Also see these links:
http://pterosaurnet.blogspot.ca/2010/05/another-thing-to-watch-for.html

http://pterosaurnet.blogspot.ca/2014/04/pneumaticity.html

http://pterosaurnet.blogspot.ca/2013/12/respiratory-cycle-of-bird_16.html

https://en.wikipedia.org/wiki/Pterosaur#Air_sacs_and_respiration

A 2009 study showed that pterosaurs had a lung-air sac system and a precisely controlled skeletal breathing pump, which supports a flow-through pulmonary ventilation model in pterosaurs, analogous to that of birds. The presence of a subcutaneous air sac system in at least some pterodactyloids would have further reduced the density of the living animal.^[18]Like modern crocodilians, pterosaurs appeared to have had a hepatic piston, seeing as their shoulder-pectoral girdles were too inflexible to move the sternum as in birds, and they possessed strong gastralia.^[45] Thus, their respiratory system had characteristics comparable to both modern archosaur clades.

"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.

http://books.google.ca/books?id=8CKYxcylOycC&pg=PA243&lpg=PA243&dq=tenopatagium&source=bl&ots=SopV9CAGec&sig=-gWOltWiFGplrU9tcXV8X8pBPUI&hl=en&ei=vyTjS5aEBoT6lwf_uMC9Ag&sa=X&oi=book_result&ct=result&resnum=6&ved=0CC8Q6AEwBQ#v=onepage&q=tenopatagium&f=false

Page 243:

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

http://archosaurmusings.files.wordpress.com/2008/07/darkwing.jpg?w=764&h=510


It is astonishing, because we can see that the structure and material of feathers is already present as the actinofibrils in the membrane.

http://www.ucmp.berkeley.edu/vertebrates/flight/pter.html
"Bird feathers are analogous to the wing fibers of pterosaurs,"


PTEROSAURS
http://www.springerlink.com/content/v8434087565413kk/fulltext.pdf?page=1
"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." 


http://www.jstor.org/pss/2400656
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": 
https://archive.org/stream/The_Pterosaurs_From_Deep_Time_by_David_M._Unwin/The_Pterosaurs_From_Deep_Time_by_David_M._Unwin_djvu.txt

"...[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". 

http://en.wikipedia.org/wiki/Pterosaur

"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]"

http://books.google.ca/books?id=idta6AVV-tIC&pg=PA20&lpg=PA20&dq=actinofibrils&source=bl&ots=2E-08Z7eLr&sig=rkiJwNwSZCbYJ9MtkYQDfQ9HDE0&hl=en&ei=0ureTJSDKMienAe_3pXtDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCUQ6AEwAg#v=onepage&q=actinofibrils&f=false
"Since they [actinofibrils] were external, they were probably epidermal structures composed of keratin as in scales and feathers."

http://en.wikipedia.org/wiki/Pterosaur
"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."


http://en.wikipedia.org/wiki/Pterosaur
"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"

BIRDS
http://en.wikipedia.org/wiki/Pennaceous_feather
"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."

http://en.wikipedia.org/wiki/Flight_feather
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]

http://www.wordnik.com/words/postpatagium
" 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."

http://www.innvista.com/science/zoology/ornithology/birdtopo.htm
"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:
http://dml.cmnh.org/2001Jan/msg00135.html
"I`m not sure exactly how feathers developed,but actinofibrils arranged in a pattern similar to flight feather rachis is very suggestive."

Earlier post:
http://pterosaurnet.blogspot.ca/2010/05/feathers.html



FOR REFERENCE:
http://www.biology-resources.com/drawing-bird-feather-structure.html

http://www.glogster.com/media/5/34/29/19/34291999.jpg

http://www.ucmp.berkeley.edu/vertebrates/flight/pterosaurwing.gif

http://upload.wikimedia.org/wikipedia/commons/thumb/d/d3/Pterosaur_wing_BW2.jpg/300px-Pterosaur_wing_BW2.jpg

http://www.pterosaur.org.uk/PDB2012/T/Patagium/Patagium08.htm

Pterosaur to bird - hand development

The pteroid is composed of two fused phalanges.
http://www.oceansofkansas.com/Pteranodon/FHSM/FHSM%20VP-2072Pteroid1.jpg

http://www.oceansofkansas.com/Pteranodon.html

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.  

http://www.seaworld.org/animal-info/info-books/raptors/physical-characteristics.htm
"The wings of many diurnal birds of prey have a vestigial claw located at the end of the thumb bone."

http://www.shearwater.nl/index.php?file=kop126.php

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

Seriema

http://en.wikipedia.org/wiki/Seriema

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 falcons, parrots and passerines.^[1] There are two species:

• Red-legged Seriema, or Crested Cariama, Cariama 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 Seriema, Chunga 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.

Paraphyletic = Ancestral

http://en.wikipedia.org/wiki/Dromaeosauridae#Flying_and_gliding
"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.

Neoteny

For reference:
http://en.wikipedia.org/wiki/Palaeognathae
"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. "

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.

http://www.sciencedaily.com/releases/2010/01/100126105429.htm

"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."

Neutrino

“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.

Categories:

• Landbirds (Owl)
• Landbirds (general)
• Landfowl
• Waterfowl (Presbyornithid line)
• Aquatic birds (Hesperornithes line)
• Waders/shorebirds
• Seabirds (Ichthyornithes line)
• Flightless birds

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)

Sophiornithidae
http://en.wikipedia.org/wiki/Sophiornithidae

Owl
http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Northern_Spotted_Owl.USFWS-thumb.jpg/220px-Northern_Spotted_Owl.USFWS-thumb.jpg

http://www.pnas.org/content/105/6/1983.full

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.

http://en.wikipedia.org/wiki/Sophiornithidae
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:

http://dragonsoftheair.wordpress.com/

"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."


http://pterosaurheresies.wordpress.com/2012/01/03/anurognathids-as-apodiform-analogs/

"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."

https://pterosaurheresies.wordpress.com/tag/binocular-vision/

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.

http://www.owlpages.com/articles.php?section=owl+physiology&title=Feathers

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.