The Branching Tree

Many existing bird orders trace back to Enantiornithes niche subgroups.

Quote:

http://en.wikipedia.org/wiki/Enantiornithes so that it is possible that enantiornithines may actually represent successive outgroups on the lineage leading to modern birds. AND http://en.wikipedia.org/wiki/Apsaravis This would mean that, rather than a radiation of primitive birds separate from the radiation that led to modern birds, "enantiornithines" would actually be steps along the way to becoming modern birds.

AND

Quote:

http://en.wikipedia.org/wiki/Enantiornithes Enantiornithine fossils appear to include waders, swimmers, fish-catchers, and hook-beaked raptors. And http://en.wikipedia.org/wiki/Bird Enantiornithes occupied a wide array of ecological niches, from sand-probing shorebirds and fish-eaters to tree-dwelling forms and seed-eaters.

Let us say for the sake of simplicity that there are 3 niche groups within enantiornithes (waders, seabirds and landbirds). Think of these as 3 major branches. From each of these major branches, a number of smaller subbranches branch off. For example, the subbranches off the wader branch lead to the variety of modern wader orders. The subbranches off the seabird branch lead to the variety of modern seabird orders. The subbranches off the landbird branch lead to the variety of modern landbird orders.
It is a branching tree. In this picture there is increasing specializations and expansion within the niche and expansion across the globe exploiting that niche..
For example, the wader groups of Enantiornithes developed into a variety of specialized wader bird orders and expanded across the globe in their niche.

Aves 3D

This is a very cool website showing bird structures in 3D:
Here is an ostrich sternum (not keeled):
http://aves3d.org/specimens/129-Struthio-camelus/specimen_elements/342-Sternum

The Basic Picture

The basic picture is that during the Cretaceous, separate primitive bird lines were established, each within its particular niche. And then each line transitioned into the corresponding modern bird orders of that niche.

FLIGHTLESS BIRDS (Ratites)

• A Dromaeosaurid* subgroup --> Ornithomimosaurids  --> Modern ratites (Ostrich (Struthio), Rhea (Rheidae), Cassowary, Emu (Casuariidae), Kiwi (Apteryx))

Dromaeosaurid
http://upload.wikimedia.org/wikipedia/commons/c/cd/Velociraptor_dinoguy2.jpg
Ornithomimid
http://upload.wikimedia.org/wikipedia/commons/thumb/3/39/Ornithomimid.jpg/800px-Ornithomimid.jpg
Ostrich
http://upload.wikimedia.org/wikipedia/commons/thumb/8/87/FlappingOstriches.jpg/643px-FlappingOstriches.jpg
Kiwi
http://0.tqn.com/d/goaustralia/1/0/9/i/kiwi.jpg

SEABIRDS (Ichthyornithes line)

• A Dromaeosaurid* subgroup --> 
• An Enantiornithes seabird subgroup --> 
• An Ichthyornithes subgroup --> Gulls, Skimmers (Charadriiformes/Lari) 
AND
• An Ichthyornithes subgroup --> Petrels (Procellariiformes), Sphenisciformes, Pelecaniformes

Enantiornithes
http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Iberomesornis-model.jpg/250px-Iberomesornis-model.jpg
Ichthyornis
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f2/Ichthyornis_BW.jpg/250px-Ichthyornis_BW.jpg
Gull
http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Black-headed_Gull_-_St_James%27s_Park%2C_London_-_Nov_2006.jpg/250px-Black-headed_Gull_-_St_James%27s_Park%2C_London_-_Nov_2006.jpg


WADERS/SHOREBIRDS

• A Dromaeosaurid* subgroup --> 
• An Enantiornithes shorebird subgroup --> Primitive shorebird (eg. Graculavus) --> Modern shorebirds - eg. plovers, oystercatchers, sandpipers (Charadriiformes/Charadrii)

Enantiornithes
http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Iberomesornis-model.jpg/250px-Iberomesornis-model.jpg
Shorebird
http://upload.wikimedia.org/wikipedia/commons/thumb/0/00/Calidris-pusilla-001.jpg/240px-Calidris-pusilla-001.jpg


AQUATIC BIRDS (Hesperornithes line)

• A Dromaeosaurid* subgroup --> 

• An Enantiornithes aquatic subgroup --> Baptornithidae (Hesperornithes) --> (primarily foot-propelled) WEB FOOT diving bird orders, eg. Cormorants (Phalacrocoracidae), Loons (Gaviidae)).
AND

• An Enantiornithes aquatic subgroup --> Hesperornithidae (Hesperornithes) --> (primarily foot-propelled) LOBE FOOT diving bird orders eg. Grebes (Podicipedidae).

Enantiornithes
http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Iberomesornis-model.jpg/250px-Iberomesornis-model.jpg
Hesperonis
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d1/Hesperornis_BW.jpg/220px-Hesperornis_BW.jpg
Loon
http://bwfov.typepad.com/birders_world_field_of_vi/images/2007/07/18/loon_2.jpg


WATERFOWL (Anatidae)

• A Dromaeosaurid* subgroup --> 

• An Enantiornithes waterbird subgroup --> Presbyornithids--> Modern Anseriformes (eg. Duck, Geese , Swan)

Enantiornithes
http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Iberomesornis-model.jpg/250px-Iberomesornis-model.jpg
Presbyornis
http://critters.pixel-shack.com/WebImages/crittersgallery/Presbyornis.jpg
Goose
http://upload.wikimedia.org/wikipedia/commons/thumb/c/c0/Magpie.goose.grooming.arp.750pix.jpg/222px-Magpie.goose.grooming.arp.750pix.jpg

LANDBIRDS (General)

• A Dromaeosaurid* subgroup --> Primitive flying birds (Enantiornithes) --> Modern Land Bird Orders

Enantiornithes
http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Iberomesornis-model.jpg/250px-Iberomesornis-model.jpg
Modern Land Bird 
http://upload.wikimedia.org/wikipedia/commons/thumb/3/32/House_sparrow04.jpg/220px-House_sparrow04.jpg


LANDFOWL

• A Dromaeosaurid* subgroup --> Primitive flying birds (Enantiornithes) --> Modern "Galliformes" (eg. Chicken, Turkey, Pheasant, Quail) and Tinamiformes (Tinamou)

Enantiornithes
http://upload.wikimedia.org/wikipedia/commons/thumb/8/89/Iberomesornis-model.jpg/250px-Iberomesornis-model.jpg
Fowl
http://upload.wikimedia.org/wikipedia/commons/thumb/7/79/Sonnerathuhn.jpg/240px-Sonnerathuhn.jpg
Tinamou
http://leesbirdblog.files.wordpress.com/2010/06/red-winged-tinamou-rhynchotus-rufescens-by-c2a9wiki.jpg


LANDBIRDS (OWL)

• A Dromaeosaurid* subgroup --> 
• Troodontid subgroup --> 
• Primitive owls (eg. The supposed "Cretaceous owls"Bradycneme and Heptasteornis) --> 
• Strigiformes (eg. owls)
AND
• Caprimulgiformes (eg. nighthawks)

Troodontid
http://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Meilong_mmartyniuk_wiki.png/250px-Meilong_mmartyniuk_wiki.png
Owl
http://upload.wikimedia.org/wikipedia/commons/thumb/1/14/Northern_Spotted_Owl.USFWS-thumb.jpg/220px-Northern_Spotted_Owl.USFWS-thumb.jpg


*Dromaeosaurids developed from pterosaurs.

ANALYSIS
So far in the analysis, we have separate primitive bird lines leading to specific modern bird orders.
All the lines trace back to Dromaeosauridae (which then traces back to Pterosauria).
The primitive bird lines are based on:

• Ornithomimosaurids
• Enantiornithes
• Ichthyornithes
• Hesperornithes
• Troodontids
• Presbyornithids

Bird Groupings

Here is one study of how modern birds can be classified.

Hackett et al. cladogram
http://www.owlpages.info/downloads/A_Phylogenomic_Study_of_Birds_Reveals_Their_Evolutionary_History.pdf

Click to enlarge.

Filling in the picture (2)

Consider all the taxa (gold bars) that extend to near the K/T extinction (65 mya). Those are Oviraptorids, Troodontids, Dromaeosaurids, Alvarezsaurids, Euenantiornithes, Hesperornithiforrms and Ichthyornis.
Each of those is a candidate for a euphyletic (ancestral) relationship with corresponding modern bird taxa.
For example the taxa labelled "modern birds" (which should read "Some modern birds") can represent the taxa of modern birds that developed from Ichthyornis.
The other modern birds that developed from the other taxa (eg from Euenantiornithes etc) are simply not shown on this chart.

Filling in the picture (1)

To repeat an important point, consider the time-based cladogram (above) that we saw earlier
Note that the group labeled "Modern birds" at the bottom right should say "Some modern birds" since modern bird taxa developed from the various taxa on the chart, such as Enantiornithes etc.

Additional fossils

Here are some additional fossils.
http://www.oceansofkansas.com/Pteranodon.html
Notice the pteroid bone. In both pictures the pteroid bone is shown pointing back toward the body. It is more likely it pointed away from the body.

The primitive bird 1st metacarpal.

Here is the primitive bird Deinonychus hand:
http://www.pnas.org/content/96/9/5111/F3.large.jpg
http://www.pnas.org/content/96/9/5111.full (figure 3)


Additional diagram of primitive bird hand (left picture):

http://upload.wikimedia.org/wikipedia/commons/thumb/3/39/Archaeo-deinony_hands.svg/220px-Archaeo-deinony_hands.svg.png

Revised total progression

Total progression

2-3-4-4-x Pterosaur
x-2-3-4-x Primitive bird (maniraptors that are not modern birds)


Note:
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."



Concerning the sesamoid:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1560000/?tool=pmcentrez
"We propose instead that the sesamoid in question was originally embedded in the tendon of a pteroid extensor or flexor muscle where it passed over the medial carpal, [actually metacarpal] and that it was pulled into the fovea after death in some specimens as a result of disarticulation of the [meta]carpal–pteroid joint."

Pterosaur wrist (5)

More on the pterosaur wrist.
http://jeb.biologists.org/cgi/content-nw/full/210/10/1663/

Fig. 4. (A) Lateral view of the right medial carpal in articulation with the distal carpal of the Cretaceous pterosaurColoborhynchus robustus. Scale bar, 25 mm. (B) Traditionally recognised articular surfaces of the right carpal-pteroid joint of Coloborhynchus, the medial carpal in distal (anterior) view showing the fovea (fov), and the head of the pteroid in proximal view. Specimen details can be found in Wilkinson et al. (Wilkinson et al., 2006). Scale as in A. (C) Reconstruction of the right wrist of Coloborhynchus in dorsal view according to descriptions provided by Bennett (Bennett, 2001; Bennett, 2006), with a sesamoid bone (ses) within the fovea, and the pteroid articulating on the side of the medial carpal. Note that the medial carpal has been rotated about its long axis by 180° with respect to A and B. The postulated trajectory of the wing-finger metacarpal extensor tendon (ten), in which the sesamoid is embedded, is also shown. Scale bar, 50 mm. (D) Reconstruction of the right wrist in dorsal view according to Wilkinson et al. (Wilkinson et al., 2006), with the pteroid at maximum elevation, and an alternative reconstruction of the sesamoid, which is shown in close association with the carpal-pteroid joint, embedded within a putative pteroid extensor tendon (origin and insertion points unknown). Scale as in C. Abbreviations as in Fig. 1. Broken line indicates a continuation of the extent of the tendon. Additional abbreviations: dc, distal carpal; f, femur; h, humerus; mc, medial carpal; pc, proximal carpal; r, radius; t, tibiotarsus; u, ulna; wf, wing-finger; wm, wing-finger metacarpal. Summary of pictures: PTEROSAURS  http://bigcat.fhsu.edu/biology/cbennett/carpals-Bring.jpg http://jeb.biologists.org/content/210/10/1663.full http://jeb.biologists.org/content/210/10/1663.full.pdf http://www.bioone.org/na101/home/literatum/publisher/bioone/journals/content/vrpa/2007/02724634-27.4/0272-4634%282007%2927%5B881%3Aaafotp%5D2.0.co%3B2/production/images/large/i0272-4634-27-4-881-f05.jpeg FIGURE 5. Photographs of A, the left (above) and right (below) carpal regions of Anhanguera santanae, AMNH 22555, in dorsal view, slightly disarticulated but in situ during preparation; B, the right preaxial carpal, Sesamoid A, and pteroid of Pteranodon sp. indet., YPM 2300, in dorsal or lateral view; and C, non-rticular (left) and articular (right) surfaces, respectively, of Sesamoid A of Pteranodon longiceps, YPM 1175. Abbreviations: art, articular surface for fovea; asp, articular surface for pteroid; ds, distal syncarpal; mciv, metacarpal IV; pc, preaxial carpal; ps, proximal syncarpal; pt, pteroid; r, radius; str, striations for attachment to its tendon; u, ulna; and sesA, Sesamoid A. Photograph of AMNH 22555 courtesy of P. Wellnhofer. http://www.bioone.org/na101/home/literatum/publisher/bioone/journals/content/vrpa/2007/02724634-27.4/0272-4634%282007%2927%5B881%3Aaafotp%5D2.0.co%3B2/production/images/large/i0272-4634-27-4-881-f03.jpeg http://archosaurmusings.files.wordpress.com/2009/04/pterowing1.jpg?w=444&h=358 http://archosaurmusings.wordpress.com/2009/04/13/where-is-the-pterosaurian-5th-finger/ The pterosaur forelimb. Black - humerus, yellow - radius & ulna, orange - pteroid, blue - metacarpals, white - phlanges of digit IV (4th phalanx not shown). http://www.reptileevolution.com/longisquama3.htm http://archosaurmusings.wordpress.com/2010/03/04/why-microraptor-should-never-be-drawn-the-same-way-again/ http://upload.wikimedia.org/wikipedia/commons/thumb/0/01/Darwinopterus.jpg/800px-Darwinopterus.jpg http://www.bioone.org/na101/home/literatum/publisher/bioone/journals/content/vrpa/2007/02724634-27.4/0272-4634%282007%2927%5B881%3Aaafotp%5D2.0.co%3B2/production/images/medium/i0272-4634-27-4-881-f02.gif http://jeb.biologists.org/content/210/10/1663/F3.medium.gif http://jeb.biologists.org/content/210/10/1663.full.pdf http://www.bioone.org/na101/home/literatum/publisher/bioone/journals/content/vrpa/2007/02724634-27.4/0272-4634%282007%2927%5B881%3Aaafotp%5D2.0.co%3B2/production/images/medium/i0272-4634-27-4-881-f01.gif http://archosaurmusings.files.wordpress.com/2009/04/ligament_function_blog.jpg?w=500&h=352 http://archosaurmusings.wordpress.com/2009/04/14/how-did-pterosaurs-extend-their-wing-finger/ DROMAEOSAURID (Maniraptor) Deinonychus antirrhopus: http://img253.imageshack.us/img253/3970/234h.jpg http://www.pnas.org/content/96/9/5111.full Left picture - Deinonychus antirrhopus: http://books.google.gr/books?id=01oUBEC9Nn4C&pg=PA97&lpg=PA97#v=onepage&q&f=false PDF pictures cannot be copied here unfortunately. Deinonychus antirrhopus: Page 97.  Dinosaur hands Page 98 Series of primitive bird hands. http://www.dinosaur-world.com/feathered_dinosaurs/wing_evolution.htm HUMAN HAND http://www.eorthopod.com/images/ContentImages/hand/hand_cmc/hand_cmc_anat02.jpg ALLOSAURUS  (dinosaur) http://www.nps.gov/museum/exhibits/dino/exb/metacarpals_dino11541a_exb.jpg

MODERN BIRD


http://shearwater.nl/seabird-osteology/SHEARWATERS/Wing_Ard-tenuirostris-wing-numbers.jpg
http://www.shearwater.nl/index.php?file=kop126.php

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

Metacarpal to phalanx articulation (hinge joint)
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d0/Gray338.png/250px-Gray338.png

http://upload.wikimedia.org/wikipedia/commons/thumb/6/6e/Gray229.png/250px-Gray229.png

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1696302/pdf/canvetj00433-0015.pdf
Unfortunately the picture from the pdf cannot be copied here. See drawing of bird wing - particularly the alula.


HINGE JOINT

http://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Gelenke_Zeichnung01.jpg/250px-Gelenke_Zeichnung01.jpg

Diagram 4
1: Ball and socket joint; 2: Condyloid joint (Ellipsoid); 3: Saddle joint; 4 Hinge joint; 5:Pivot joint;

PTEROIDS


http://www.oceansofkansas.com/Pteranodon.html
http://www.oceansofkansas.com/Pteranodon/FHSM/FHSM%20VP-2183-3.jpg

http://www.oceansofkansas.com/Pteranodon/FHSM/FHSM%20VP-2072Pteroid1.jpg

http://pds17.egloos.com/pds/201003/22/16/e0091316_4ba63cdbce3d8.jpg

http://bigcat.fhsu.edu/biology/cbennett/pteroid-reconstruction.jpg

http://www.mananatomy.com/body-systems/skeletal-system/metacarpal-bones

Head of Metacarpal Bones:

The head is provided with a surface for articulation with the proximal phalanx. This area curves farther over its anterior aspect than the posterior. It is convex from before backwards and from side to side and is wider anteriorly than posteriorly. It is notched on its anterior aspect and its edges form two prominent tubercles, which are sometimes grooved for the small sesamoid bones.

First metacarpal bone:

The first metacarpal differs from the others in being free at its distal end. Its proximal end possesses only a carpal articular facet and is not articulated with other metacarpal bones. The first metacarpal bone is the shortest and stoutest of the series. Its body is compressed from before backwards. Its head is of large size and is grooved on its anterior aspect for the sesamoid bones. The base is provided with a saddle-shaped surface for articulation with the trapezius.

http://en.wikipedia.org/wiki/Carpal#Evolutionary_variations
The wing of a modern bird, for example, has only two remaining carpals; the radiale (the scaphoid of mammals) and a bone formed from the fusion of four of the distal carpals.^[14]



http://www.eurekalert.org/pub_releases/2002-08/uonc-sso081402.php
Drs. Alan Feduccia and Julie Nowicki of the University of North Carolina at Chapel Hill have done just that. They opened a series of live ostrich eggs at various stages of development and found what they believe is proof that birds could not have descended from dinosaurs. They also discovered the first concrete evidence of a thumb in birds.

"Whatever the ancestor of birds was, it must have had five fingers, not the three-fingered hand of theropod dinosaurs," Feduccia said. "Scientists agree that dinosaurs developed 'hands' with digits one, two and three -- which are the same as the thumb, index and middle fingers of humans -- because digits four and five remain as vestiges or tiny bumps on early dinosaur skeletons. Apparently many dinosaurs developed very specialized, almost unique 'hands' for grasping and raking. "Our studies of ostrich embryos, however, showed conclusively that in birds, only digits two, three and four, which correspond to the human index, middle and ring fingers, develop, and we have pictures to prove it," said Feduccia, professor and former chair of biology at UNC. "This creates a new problem for those who insist that dinosaurs were ancestors of modern birds. How can a bird hand, for example, with digits two, three and four evolve from a dinosaur hand that has only digits one, two and three? That would be almost impossible."
and
If one views a chicken skeleton and a dinosaur skeleton through binoculars they appear similar, but close and detailed examination reveals many differences, Feduccia said. Theropod dinosaurs, for example, had curved, serrated teeth, but the earliest birds had straight, unserrated peg-like teeth. They also had a different method of tooth implantation and replacement.

Pterosaur wrist (4)

http://bigcat.fhsu.edu/biology/cbennett/pteroid-articulation.html


"The medial aspect of the left preaxial carpal is visible (upper right), whereas the right preaxial carpal somewhat below it presents its lateral aspect.The articular surface for the pteroid (asp) is faintly visible.
Abbreviations: art, articular surface for fovea; asp, articular surface for pteroid; ds, distal syncarpal; mciv, metacarpal IV; pc, preaxial carpal; ps, proximal syncarpal; pt, pteroid; r, radius; str, striations for attachment to its tendon; u, ulna; and sesA, Sesamoid A."

Pterosaur wrist (3)

enlarge figure

"FIGURE 2. Skeletal reconstruction of Anhanguera (modified from Wilkinson et al., 2006) showing a medially directed pteroid and traditional propatagium (dashed line), the anteriorly directed pteroid and extensive propatagium advocated by Wilkinson and colleagues (2006; dashed line), and a longer anteriorly directed pteroid 76% ulnar length as in Cycnorhamphus and resulting larger propatagium (dotted line). See text for explanation. Abbreviations: ant-pt, anteriorly directed pteroid; bra, brachiopatagium; cyc, leading edge of larger propatagium; cyc-ant-pt, Cycnorhamphus-length anteriorly directed pteroid; ext, leading edge of extensive propatagium; fem, femur; hum, humerus; mc, metacarpus; med-pt, medially directed pteroid; pc, preaxial carpal; pro, propatagium; r+u, radius and ulna; tib, tibia; trad, leading edge of traditional propatagium; uro, uropatagium; and wp1-4, wing phalanges 1-4."

Pterosaur wrist (2)

Pterosaur wrist (1)

http://jeb.biologists.org/cgi/content/full/210/10/1663/

"Fig. 1. Skeletal reconstruction of the Cretaceous pterosaur Anhanguera santanae in dorsal view, showing the elongated wing-finger (wf) supporting the cheiropatagium (ch), the unique pteroid bone (pt) supporting the propatagium (pro) and the cruropatagium (cr) medial to the leg. Two possible reconstructions of the pteroid are shown, with corresponding outlines of the propatagium: a forward-pointing orientation (solid line), and a medial orientation (broken line). Scale bar, 200 mm. Additional abbreviations: dc, distal carpal; f, femur; h, humerus; mc, medial carpal; pc, proximal carpal; r, radius; t, tibiotarsus; u, ulna; wf, wing-finger; wm, wing-finger metacarpal."

* Comparing dinos to birds

Many people think that birds evolved from dinosaurs.
To be more precise their claim is that birds evolved from non-maniraptoran coelurosaurs.
And yet when they compare a "dinosaur" to a bird, they do not take a drawing of a non-maniraptor coelurosaurian, (eg. tyrannosaur) but they take a drawing of a non-neornithine Aves (eg. Ichthyornithes) creature and compare it with a modern bird.
This of course is irrelevant.
The issue is NOT WITHIN AVES but between non-maniraptor coelurosaurs and maniraptors.

Here are some non-maniraptor coelurosaurs.
Tyrannosaur:

Compsognathid:

These are believed to be sister taxa to the non-maniraptor coelurosaur ancestor of birds. But as we all know, the dino to bird theory enthusiasts never present any pictorial representation of any purported non-maniraptor coelurosaur, bird ancestor.
So who knows what it looks like.

But certainly if we want to understand what the dino to bird theory is actually claiming, we need to compare the non-maniraptor coelurosaurs to modern birds and not non-neornithine Aves creatures to modern birds.

Pterosaur Hand

Here is a great drawing of a pterosaur

It shows the "pteroid bone" which is a neomorph. It shows the other fingers including the extended 4th finger.
It shows that the pterosaurs bent their wings at the junction of the metacarpals and the fingers.
This is different than their descendant modern birds that have fused the hand so they no longer bend at the junction of the metacarpals and the fingers. Instead modern birds bend at the wrist.

Primitive to Modern Birds

Here is a first cut at the development of primitive bird groups to modern bird groups.

See the updated version here:
http://pterosaurnet.blogspot.com/2012/02/overview-of-basic-ideas.html

Prow Beaks

I have been analyzing the pterosaurs to see if they actually had beaks as we use the term "beak". Rhamphorhynchoid stands for "prow beaks". This kind of "beak" is not the extending kind of beak that we associate with the word "beak".
When the pterosaurs evolved into primitive birds, it may well be that the most basal primitive "beakless" birds had snouts, like prow-beaked pterosaurs.
And "beaks", as we use the word, evolved within the primitive birds.
This idea is in line with the fossil record.
This idea requires more analysis but it seems right to me at this point.

Protofeathers on the wing membrane

Here is a reference to the "pycnofibres"  - even as early as the Rhamphorhynchus.
If they are  related to feathers they correspond to downy feathers and not pennaceous (contour) feathers. 


http://en.wikipedia.org/wiki/Pterodactylus
"The wings were long, and the wing membranes appear to have lacked the furry covering of pycnofibres present in some other pterosaurs (such as Pterorhynchus and Jeholopterus)."

http://en.wikipedia.org/wiki/Pterorhynchus
"This type specimen consists of an articulated, nearly-complete skeleton with remains of the integument. These included the wing membrane, hair-like structures, a long version of the vane found at the end of "rhamphorhynchoid" tails, and a head crest with both a low bony base and a large keratin extension"

http://en.wikipedia.org/wiki/Jeholopterus
"The specimen is crushed into a slab and counterslab pair, so that parts of the specimen are preserved on one side of a split stone and some on the other. This includes exquisite preservation of carbonized skin fibers and, arguably, "hair" or "protofeathers." The fibers are preserved around the body of the specimen in a "halo." Wing tissue is preserved, though its extent is debatable, including the exact points of attachment to the legs (or if it attached to the legs at all). In 2009 Alexander Kellner published a study reporting the presence of three layers of fibres [actinofibrils] in the wing, allowing the animal to precisely adapt the wing profile.[3]"

Painten Pelican

Here is a reference to a very interesting picture:
http://pterosaur-net.blogspot.com/20...-throwing.html
"An unusual pterosaur skull, nicknamed the Painten Pelican, has caused a lot of discussion amongst pterosaur palaeontologists because it is, superficially at least, so danged weird (see image, above). The specimen comprised a complete skull, mandible and cervical vertebra and, if you’re around in Southern Germany, you can see it for yourself: it’s on display in the Solnhofen Museum. A cast and UV photographs of the specimen were making quite a buzz at the 2007 Flugsaurier Meeting, and, apparently, the specimen is very slowly being written up."