Liaodactylus, a new gnathosaurine pterosaur

Figure 1. Liaodactylus (in color in in situ compared to Gnathosaurus.

Figure 1. Liaodactylus (in color in in situ compared to Gnathosaurus. The portion of the rostrum above the antorbital fenestra remains unknown. A short crest may or may not have been present.

Liaodactylus primus (Zhou et al. 2017) was considered the earliest filter-feeding pterosaur. Here it nests with the Solnhofen specimen of Gnathosaurus. Distinctly, Liaodactylus has short premaxillary teeth and longer dentary teeth than maxillary teeth. The skull was small, only half the length of Gnathosaurus, but with similar proprotions. The jugal was not elevated and so did not shrink the orbit.

FIgure 2. Subset of the large pterosaur cladogram focusing on the clade Dorygnathia and the clade within it, the Ctenochasmatidae.

FIgure 2. Subset of the large pterosaur cladogram focusing on the clade Dorygnathia and the clade within it, the Ctenochasmatidae. Here Liaodactylus nests as a sister to Gnathosaur, a basal ctenochasmatid.

Zhou et al. did not provide
a specimen-based phylogenetic analysis. but used only one taxon for each genus and so missed out on the gradual accumulation of traits that nested Liaodactylus with Gnathosaurus. Instead they nested it with Ctenochasma.

Zhou et al. used the data matrix
of Andres, Clark and Xu 2004, which nested Kryptodrakon as the basalmost pterodactyloid. As we learned earlier, those authors reconstructed the few bits and pieces of Kryptodrakon as a small Pterodactylus-like pterosaur, when it should have been reconstructed as a larger, but very gracile Sericipterus, which was found in the same deposits, but would not have made so many headlines.

References
Andres B, Clark JM and Xu X 2010.A new rhamphorhynchid pterosaur from the Upper Jurassic of Xinjiang, China, and the phylogenetic relationships of basal pterosaurs, Journal of Vertebrate Paleontology 30: (1) 163-187.
Andres B, Clark J and Xu X 2014. The Earliest Pterodactyloid and the Origin of the Group. Current Biology (advance online publication)
DOI: http://dx.doi.org/10.1016/j.cub.2014.03.030
Zhou C-F, Gao K-Q, Yi H, Xue J, Li Q and Fox RC 201. Earliest filter-feeding pterosaur from the Jurassic of China and ecological evolution of Pterodactyloidea. R. Soc. open sci. 4: 160672. http://dx.doi.org/10.1098/rsos.160672

 

You heard it here first: no gender differences detected in pterosaur pelves

A new paper on wukongopterid crests
(Cheng et al. 2017) reports, “We also show that there is no significant variation in the anatomy of the pelvis of crested and crestless specimens. We further revisit the discussion regarding the function of cranial structures in pterosaurs and argue that they cannot be dismissed a priori as a valuable tool for species recognition.”

The subject of gender differences
in pterosaur pelves was examined here, here and here. While the subject of gender differences in pterosaur crests was examined here, here and here in previous posts going back several years (Fig. 1).

Female Pteranodon?

Figure 3. Pteranodon (left) and Nyctosaurus (right) pelves. KUVP 933 (I)  is closer to Nyctosaurus in morphology. It is not a female Pteranodon. It belongs to a big Nyctosaurus. Note the HUGE individual variation presented here among putative congeneric specimens.

Nice to see published work
rejecting the hypotheses by Bennett 1992 that linked crest size to pelvic canal size. Bennett did not realize the large opening pelvis was that of a large nyctosaurid (Fig. 1), as in all specimens of Nyctosaurus. Cheng et al. report, “there is no direct association of the skulls and pelves that could back this hypothesis (e.g., Kellner and Tomida 2000). Re-evaluation of several specimens attributed to Pteranodon has shown that in some cases there are sufficient morphological differences other than the shape and size of the cranial crest, supporting a larger taxonomic diversity within what can be called the Pteranodon-complex (Kellner 2010).” Here (Fig. 2) smaller more primitive Pteranodon specimens have smaller crests, just as smaller more primitive tapejarids do.

Figure 2. The Tanking-Davis specimen compared to other forms. Specimen w and specimen z appear to be the closest to the Tanking-David specimen. Specimen 'w' = Pteranodon sternbergi? USNM 12167 (undescribed). Specimen 'z' = Pteranodon longiceps? Dawndraco? UALVP 24238. Click to enlarge.

Figure 2. The Tanking-Davis specimen compared to other forms. Specimen w and specimen z appear to be the closest to the Tanking-David specimen. Specimen ‘w’ = Pteranodon sternbergi? USNM 12167 (undescribed). Specimen ‘z’ = Pteranodon longiceps? Dawndraco? UALVP 24238. Click to enlarge.

Then there is the Hamipterus association…

According to Cheng et al. “Hamipterus tianshanensis bears a  premaxillary crest that, in similar sized individuals, showed consistently two distinct morphotypes: one with larger and more robust crests, and the second with smaller and more delicate crests. These morphotypes were tentatively regarded as males and females, respectively (Wang et al. 2014a). This occurrence constitute, to our knowledge, the best argument favoring sexual dimorphism expressed by cranial crests.” Of course these could be different ages, alpha and beta individuals (= individual variation leading to rapid phylogenetic changes), tribes (familial clades), or male and female. Pterosaurs have been competing for mating privileges since before they had wings, in Cosesaurus, for instance.

And there is Caiuajara
where Cheng et al. report, “Caiuajara (admittedly very distantly related to the Wukongopteridae), there seems a continuum in the appearance and development of the cranial crest, present in this taxon at a very young ontogenetic stage (Manzig et al. 2014).”

Cheng et al. conclude: “the variation in shapes and sizes of cranial crests that are found in pterosaurs, associated with other morphological features, should not be understated as being a powerful tool for understanding their diversity.”

No images or reconstructions
were offered of the pelves under study (as provided in Fig. 3). Precise measurements in a series of tables were presented. No phylogenetic analysis was attempted by Cheng et al., but you can see the results of such a test here, at the large pterosaur tree where five specimens attributed to Darwinopterus and additional others attributed to other wukongopterids lump and separate without loss of resolution.

As reported earlier
I have not found two Rhamphorhynchus specimens that score the same, except for a juvenile of the largest species. That goes the same for Pterodactylus, Germanodactylus, Pteranodon (Fig. 2), Darwinopterus (Fig. 3) or any other genus represented by a large number of individual specimens. They all nest in phylogenetic order, lumped and split by a variety of traits. Note the HUGE individual variation presented here among putative congeneric specimens.

Figure 1. Click to enlarge. The five specimens of Darwinopterus to scale and in phylogenetic order preceded by six more primitive taxa. The ZMNH 8802 specimen is a female associated with an egg. The others genders shown are guesses by Lü et al. 2011a. Note the skull did not elongate, it actually shrank in the vertical dimension, probably reducing its weight. The female is crestless because it is the most primitive of the five known Darwinopterus specimens. The odds that the remaining four specimens are all males is relatively small.

Figure 3. Click to enlarge. The five specimens of Darwinopterus to scale and in phylogenetic order preceded by six more primitive taxa. The ZMNH 8802 specimen is a female associated with an egg. The others genders shown are guesses by Lü et al. 2011a. Note the skull did not elongate, it actually shrank in the vertical dimension, probably reducing its weight. The female is crestless because it is the most primitive of the five known Darwinopterus specimens. The odds that the remaining four specimens are all males is relatively small.

References
Cheng X, Jiang S-X, Wang X-L and Kellner AWA 2017. Premaxillary crest variation within the Wukongopteridae (Reptilia, Pterosauria) and comments on cranial structures in pterosaurs. Anais da Academia Brasileira de Ciencias. http://dx.doi.org/10.1590/0001-3765201720160742

Hatzegopteryx: one error in cervical identification leads to trouble

Azhdarchid pterosaurs
as we learned earlier, first achieved their slender proportions in small, sand-piper-like taxa similar to n44 and n42 during the Late Jurassic (Fig. 1). Coeval and later taxa grew larger, some attaining stork-like and then giraffe-like sizes while maintaining their slender proportions.

Azhdarchids and Obama

Figure 1. Click to enlarge. Here’s the 6 foot 1 inch former President of the USA alongside several azhdarchids and their predecessors. Most were knee high. The earliest examples were cuff high. The tallest was twice as tall as a human male.

Extant storks are stalkers
whether wading or on firmer substrates. That analogy brings us, once again, to the Naish and Witton 2017 concept of azhdarchids as terrestrial stalkers. They revisit the subject  a third time (after Witton and Naish  2008. 2015), but now freshly armed with the evidence of a large short cervical from Hatzegopteryx, a giant pterosaur from Romania.

The big question is: which cervical is it?

In giant derived azhdarchids.
like Quetzalcoatlus and Hatzegopteryx, half the cervicals (1-3 and 8) are not elongate and the other half (4-7) are elongate.

Unfortunately and earlier
Witton and Naish 2008 mistakenly numbered the cervicals of Phosphatodraco 4-9, when they should have labeled them 3-8 (Fig. 2). They saw that neural spine on #7, which they thought was #8.

Cervical number 8 is always short in azhdarchids
and if correctly identified would have allowed the possibility that Hatzegopteryx had a typical azhdarchid neck. Cervical number 5 is always the longest in giant azhdarchids and Phospatodraco, which gives workers a starting point if the bones are scattered or incomplete at the ends.

But Naish and Witton took it the other way
and with their misidentification of a wide cervical number 7 they imagined a wide cervical series for Hatzegopteryx. And with that they thought they had more evidence for terrestrial stalking instead of aquatic wading, as practiced by all ancestors back to the Late Jurassic. I’m not saying azhdarchids didn’t pick up a few tidbits on land. I am saying they and all their ancestors were built like living sandpipers, stilts and herons, which find their diet in the shallows.

Figure 2. Black images are from Naish and Witton 2017. Cervical series is from Witton and Naish 2008. Purple and red are added here. Improper cervical identity in 2008 led to bigger problems in 2017.

Figure 2. Black images are from Naish and Witton 2017. Cervical series is from Witton and Naish 2008. Purple and red are added here. Improper cervical identity in 2008 led to bigger problems in 2017 where the authors switched real for imaginary in their graphic, which makes it look like they had more data than they really did. BTW, none of these belly-flopping pterosaurs could have taken off in this fashion.

As much as Naish and Witton write about azhdarchids,
they should not be making basic mistakes over and over again. Not only do they misidentify a cervical, they illustrate their pterosaurs doing belly flops in a purported take-off configuration that has no chance of succeeding. See here, here and here for details.) And finally they should no longer consider that pterosaurs had nine cervicals. That goes back to S. Christopher Bennett’s PhD thesis in which he considered vertebrae number 9 to be a cervical since it did not contact the sternum. Even so, it bore long ribs and was located inside the thorax.

Pictured here
(Fig. 3) is the Hatzegopteryx cervical in question. Compared to both Phosphatodraco (Fig. 2) and Quetzalcoatlus sp. (Fig. 3) this is cervical #8, the short one, not cervical #7, the long one.

Figure 3. Hatzegopteryx cervical. If it is number 7, as Naish and Witton suggest, then it is very short and likely would be part of a very short neck. But if it is number 8, then the proportions are typical for azhdarchids. This is where Occam's Razor might have been useful.

Figure 3. Hatzegopteryx cervical. If it is number 7, as Naish and Witton suggest, then it is very short and likely would be part of a very short neck. But if it is number 8, then the proportions are typical for azhdarchids. This is where Occam’s Razor might have been useful.

Some azhdarchids and their kin
have a tall neural spine only on cervical #8. Quetzalcoatlus is in this clade. Some, like Zhejiangopterus and Chaoyangopterus, have no tall neural spines. That’s also the case with the tiny basalmost clade members. By contrast, the flightless pterosaur, JME-Sos 2428 has a tall neural spine on cervicals 6-8, which makes me wonder if Phosphatodraco (Fig. 2) is a sister to it, given the present limited amount of data.

The Domino Effect
When Naish and Witton decided that Hatzegopteryx cervical #8 was #7, that mistake unleashed the possibility that they had discovered the first “short neck” azhdarchid! They must have been excited.

What Naish and Witton did not show you…
In lateral view, the Hatzegopteryx cervicals Naish and Witton illustrated actually look normal for an azhdarchid, but in dorsal view the omitted cervicals would have to have been twice as wide as typical and no longer cylinders (Fig. 2). So the “short” neck was really a “wide flat” neck, but that does not have the same headline cache. Such a major departure from the azhdarchid bauplan should have caused Naish and Witton to reconsider that their ‘discovery’ was actually a simple error in identification, now percolating online for the last 8 years.  Hope this helps quell the notion!

References
Naish D and Witton MP 2017. Neck biomechanics indicate that giant Transylvanian azhdarchid pterosaurs were short-necked predators. PeerJ 5:e2908; DOI 10.7717/peerj.2908
Witton MP and Naish D 2008. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLOS ONE 3:e2271 DOI 10.1371/journal.pone.0002271.
Witton MP and Naish D 2015. Azhdarchid pterosaurs: water-trawling pelican mimics or terrestrial stalkers? Acta Palaeontologica Polonica 60:651660 DOI 10.4202/app.00005.2013.

Brian Switek blog
wiki/Hatzegopteryx

New pterosaur website: www.pteros.com

I see some great things
in the new pterosaur website http://www.pteros.com produced by several artists who show pterosaurs in vivo with skin, fur, colors, highlights and shadows (no skeletons). Those known from only a skull or other parts are illustrated as complete, no doubt based on phylogenetic bracketing.

Nine young, male artists
listed here contribute to the website. The pterosaurs are listed alphabetically here. Pterosaur families are listed here. There environments/formations are listed here. They have a newsletter, but I have not yet seen my first one.

Unfortunately,
like most pterosaur workers, these nine artists don’t know what a pterosaur is. They report, “They were not dinosaurs as most assume, instead being flying reptiles and rather close relatives.” That’s a major weakness because we know what pterosaurs are based on a large scale (674 taxa) phylogenetic analysis, the large reptile tree. And they are more closely related to living lizards than to living birds/dinosaurs. And then there’s the literature (Peters 2000), which has been largely ignored by workers in favor of traditional hypotheses unable to provide specific data.

Fortunately
several of the artists have followed the narrow chord wing with hind limbs outstretched like horizontal stabilizers with pedal lateral digit 5 unbound from posterior uropatagia.

Unfortunately,
several others have not. They continue to follow old deep chord paradigms.

Fortunately,
most of these artists know how to bounce light off of surfaces and their use of perspective and camera angle is fascinating.

Unfortunately
several artists do not have good skeletons under those surfaces. It is so important to precise;y follow the fossil data and not make things up.

Fortunately
there are several artists involved here and they should be providing guidance to each other to avoid errors and ‘raise their game. ‘

Unfortunately
some of the text (as in Rhamphorhynchus) mistakes small adults for babies (Prondvai et al. 2012, and we’ll talk about that paper again tomorrow). Although some papers are referred to, no references are provided. I have not looked at every web page. So, the above comments represent my views on a quick run through…

While we’re talking about pterosaur art…
I found this wonderful Zhenyuanopterus online (Fig. 1, NOT at pteros.com). Not sure who the artist is, but it has an excellent morphology with narrow chord wings and horizontal stabilizer-like hind limbs. If you know the artist, send me the name so I can give credit.

Figure 1. Excellent Zhenyuanopterus by an unknown artist. I'd be happy to provide credit once that artist becomes known.

Figure 1. Excellent Zhenyuanopterus by an unknown artist. I’d be happy to provide credit once that artist becomes known.

References
Peters D 2000. A reexamination of four prolacertiforms with implications for pterosaur phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106: 293–336.
Prondvai E, Stein K, Osi A, Sander MP 2012.
Life History of Rhamphorhynchus Inferred from Bone Histology and the Diversity of Pterosaurian Growth Strategies. PLoS ONE 7(2): e31392. doi:10.1371/journal.pone.0031392

 

Another look at the smallest adult pterosaur – AND its hatchling

Earlier we looked at the smallest adult pterosaur, B St 1967 I 276 or No. 6 in the Wellnhofer (1970) catalog. Here (Fig. 1) it is compared to an adult leaf chameleon, Brookesia micro, one of the smallest living lizards and to the Bee hummingbird, one of the smallest living birds. Also shown are their hatchlings and eggs.

Figure 1. The smallest of all adult pterosaurs, B St 1967 I 276 or No. 6 in the Wellnhofer (1970) catalog compared to scale with the living leaf chameleon (Brookesia micro) sitting on someone's thumb. Also shown are hypothetical eggs and hatchlings for both. These lepidosaurs had tiny eggs and hatchlings.

Figure 1. The smallest of all adult pterosaurs, B St 1967 I 276 or No. 6 in the Wellnhofer (1970) catalog compared to scale with the living leaf chameleon (Brookesia micro) sitting on someone’s thumb. Also shown are hypothetical eggs and hatchlings for both. These lepidosaurs had tiny eggs and hatchlings, relatively larger in the chameleon, based on pelvis size and average 1/8 size for other pterosaur hatchlings.

 

Traditional paleontologists
don’t buy the argument that No. 6 was an adult, even though it is much larger than the smallest lizard and about the size of the smallest bird. Worse yet, they refused to test it in phylogenetic analysis. So, the  impasse remains.

Figure 2. Smallest known bird, Bee hummingbird, compared to smallest known adult pterosaur, No. 6 (Wellnhofer 1970). Traditional workers consider this a hatchling or juvenile, but in phylogenetic analysis it does not nest with any 8x larger adults.

Figure 2. Smallest known bird, Bee hummingbird, compared to smallest known adult pterosaur, No. 6 (Wellnhofer 1970). Traditional workers consider this a hatchling or juvenile, but in phylogenetic analysis it does not nest with any 8x larger adults. This image is slightly larger than life size at 72dpi. Note the much smaller eggs produced by the tiny pterosaur. 

 

Pictures tell the tale.
You can see for yourself. No. 6 is substantially smaller than other tiny pterosaurs just as the bee hummingbird is substantially smaller than other hummingbirds.The hatchling was substantially smaller than both the leaf chameleon and bee hummingbird hatchlings based on their larger egg size/pelvis opening.

Earlier we looked at isometric growth in several pterosaurs, with hatchlings matching adults in morphology. Earlier we also took note of the danger of desiccation to hatchling pterosaurs until they reached a certain size/volume, so they probably roamed the leaf litter, which is probably when pterosaurs became quadrupeds and developed elongate metacarpals 4x.

References
Hedges SB and Thomas R 2001. At the Lower Size Limit in Amniote Vertebrates: A New Diminutive Lizard from the West Indies. Caribbean Journal of Science 37:168–173.
Wellnhofer P 1970. 
Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Pterodactylus

SVP 21 – a new largely complete istiodactylid pterosaur with a tail!

Rodrigues et al. 2015
describe a new istiodactylid pterosaur (not this one, Fig. 1) with a tail. I have not seen it.

Istiodactylus

Figure 1. This is the Istiodactylus holotype preserved without a tail. I have not seen the pterosaur described in the Rodrigues et al abstract.

From the abstract
“The Istiodactylidae is a clade of Early Cretaceous pterosaurs which possess very distinct teeth, with crowns triangular in shape and strongly compressed labiolingually. A new specimen from this unit is here reported and comprises the most complete istiodactylid found so far. It is an almost complete skeleton of a young animal, with skull, mandible, most of the vertebral column, pectoral and pelvic girdles, most forelimbs and part of the hind limbs. It presents the first information on the tail of the Istiodactylidae and gives a minimum length of 15 caudals. All caudal centra have an elongated cylindrical shape and show no pneumatic foramina. The vertebrae get gradually thinner. The last nine vertebrae show a gradual reduction in length as well. The last caudal is longer than the preceding one but it is the thinnest, with a posterior end a mere 0.3 mm wide. The istiodactylid tail, as expected from pterodactyloids, is short, but it differs from the tail of Pteranodon, which has duplex centra and ends in a caudal rod.”

Actually
that should be paired and parallel caudal rods in Pteranodon and only two specimens preserve a tail. YPM 2462 is represented only by 6 discontinuous caudals and rods. UALVP 24238 (Fig. 2) includes most of the rest of the Pteranodon and the more complete caudals 2-10 of the tail.

Figure 3. The UALVP specimen of Pteranodon. Note the lack of taper in the rostrum along with the small size of the orbit.

Figure 2. The UALVP specimen of Pteranodon. Note the lack of taper in the rostrum along with the small size of the orbit.

Tails in ornithocheirids
The last caudal of the new istiodactylid, at one-third of a millimeter in width, is remarkable in a pterosaur the size of an istiodactylid. By comparison, the more basal ornithocheirid, Zhenyuanopterus (Fig. 3) has a rather extensive tail of at least 40 caudals terminating in a series of extremely thin bones less than a millimeter in length. The tail is longer than the femur + half the tibia.

In Haopterus, an even more basal ornithocheirid, the tail is about as long as its tibia. Boreopterus has a tail almost as long as its hind limb. JZMP embryo has a tail at least as long as its femur. Yixianopterus has a tibia-length tail. The Anhanguera tail is almost a femur in preserved length. Barbosania preserves just a few continuous causals.

Some of these tail lengths
are much longer than expected in ‘pterodactyloid’-grade pterosaurs. Much of that has to deal with the four origins for ‘pterodactyloid’-grade pterosaurs and the traditional biases that expect certain traits under false assumptions of phylogeny that nest short-tailed Pterodactylus close to the origin of all ‘pterodactyloid’-grade pterosaurs.

Zhenyuanopterus

Figure 3. The orinithocheirid Zhenyuanopterus. Note the tail length.

The large pterosaur tree nests Pteranodon (Fig. 2) far from ornithocheirids (Fig. 3). They share few traits other than a warped deltopectoral crest of distinctive designs. Pteranodon is a giant germanodactylid. Ornithocheirids are giant scaphognathids with cycnorhampids as sister taxa. So comparisons to the tail of Pteranodon are illogical in this abstract.

Finally, 
few ornithocheirids fuse their bones. So the new istiodactylid may not be immature, based on prior studies that consider lack of fusion an ontogenetic character. Phylogenetic studies show that pterosaur bone fusion is largely phylogenetic, following patterns established in lepidosaurs (Maisano 2004), not archosaurs.

References
Rodrigues T et al. 2015.
An almost complete istiodactylid (Pterosauria, Pterodactyloiidea) from the Cretaceous of China provides the first information on the tail of this clade.

 

Data denial you can listen to on a podcast

Dr. Mark Witton

Dr. Mark Witton

Dr. Mark Witton is a paleontologist,
author and illustrator, but based on a Liz Martin interview podcast denies the existence of pterosaur ancestors. Like his friends, Dr. David Hone (another data denier), and Dr. Darren Naish, Dr. Witton believes pterosaurs “appeared fully formed in the fossil record. We don’t have the pterosaur Archaeopteryx.”

Sadly this purposefully ignores 
the published literature (Peters 2000 is now 15 years old) online phylogenetic analyses (now 4 years old) and YouTube videos (just a few weeks old) that all provide a long list of pterosaur ancestors that demonstrate a gradual accumulation of pterosaur traits. Why does Dr. Witton prefers to hide his head in the sand rather than examine, test and/or accept published studies? Could this be academic bigotry? (definition: intolerance toward those who hold different opinions from oneself)

Witton believes pterosaurs “are close relatives of dinosaurs.”
If so, then were are the common ancestors that show a gradual accumulation of character traits? Answer: You can’t find them because they are not there. Other taxa share more traits with pteros and dinos than either does with each other. This is the outmoded “Ornithodira” concept.
Witton says he did not expect
that the Jurassic pterosaur, Dimorphodon would be adept at walking on the ground (despite having digitigrade pedes and fully interned femoral heads). Again, published literature demonstrates just the opposite (Padian 1983). Glad to see that Dr. Witton is getting on board with a more terrestrial Dimorphodon.
Dr. Witton waxed on about Solnhofen juvenile and subadult pterosaurs,
agreeing with Bennett (1995) who lumped Rhamphorhynchus into one species by plotting long bone lengths on a graph. Witton thought different species should have a dramatic difference in wing shape. Not so. He didn’t mention foot shape and overall morphology, which varies quite widely and logically when phylogenetic analysis is employed (Fig. 2).
Figure 3. Bennett 1975 determined that all these Rhamphorhynchus specimens were conspecific and that all differences could be attributed to ontogeny, otherwise known as growth to maturity and old age. Thus only the two largest specimens were adults. O'Sullivan and Martill took the brave step of erecting a new species. The n52 specimen is at the lower right. Click to enlarge.

Figure 2 Bennett 1975 determined that all these Rhamphorhynchus specimens were conspecific and that all differences could be attributed to ontogeny, otherwise known as growth to maturity and old age. Thus only the two largest specimens here were adults. Witton agrees that all these are conspecific. Do you agree with Witton? Decide for yourself. Click to enlarge.

Witton follows the Lü et al. (2009) analysis
that nested Darwinopterus as a transitional fossil combination of pterodactyloid skull and basal pterosaur post crania. Other analyses ( Wang et al 2009, Andres 2013, Peters online) do not support that hypothesis. Only Peters online (based on Peters 2007) includes a large selection of sparrow-sized Solnhofen pterosaurs, keys to the origin of all later clades. Along the same lines, Witton believes in Modular Evolution, which is falsified in phylogenetic analysis and apparently occurs only in their vision of Darwinopterus.
Witton reports that some azhdarchids had short necks.
Not sure which azhdarchids he is talking about. Evidently that is sneak preview on unpublished papers. The large pterosaur tree indicates that going back to the Late Jurassic, all azhdarchids and their ancestors had very long necks, even as hand-sized taxa (Fig. 3).
The Azhdarchidae.

Figure 3. The Azhdarchidae. Click to enlarge. No short necks here, except way down toward the left. Not saying they could not evolve. Just saying I haven’t seen them yet. 

Witton reports there are small birds but no small pterosaurs
from the Upper Cretaceous — but no small dinosaurs either — so suggests there may be a preservational bias in the lack of small pterosaurs… but no such bias for small birds. Actually there are small bird fossils from the Late Cretaceous, and they ARE dinosaurs, and no small pterosaurs. Lacking tiny pteros in the Late Cretaceous spelled their doom. Only small and tiny pterosaurs survived the Latest Jurassic extinction event and only these were basal to later giants. So no darwinopterids had descendants in the Cretaceous. Because there were no tiny Late Cretaceous pterosaurs, none survived the Late Cretaceous extinction event.
Can we blame this on a bad mentor?
Dr. Witton has accumulated a great deal of pterosaur knowledge and expresses it wonderfully in his many paintings. Unfortunately, like Hone and Naish, he was ‘raised’ by wrong-minded mentors and continues his false beliefs (= he has not tested his or competing hypotheses in phylogenetic analyses) to this day. Earlier we looked at the many problems in Dr. Witton’s book on pterosaurs.
Dr. Don Prothero

Dr. Don Prothero

Some insight into that sort of thinking…
it’s not that uncommon.
Dr. Don Prothero in a YouTube Video provides great insights into the Creationist mindset that finds strong parallels in the current thinking of Dr. Mark Witton, Dr. David Hone and Dr. Darren Naish.

Notes from the Prothero video
  1. Humans are not rational machines
  2. We all employ motivated (emotional, wants and needs) reasoning, not logical reasoning
  3. We are all belief engines and we all create a world view or core belief
  4. Because of that we don’t like to hear anything that does not fit our world view
  5. AND we use reason to do what we want data to do, not what its telling us. We use ANY tricks to make the evidence of the world fit our beliefs, or twist it to fit, or deny it or ignore it. Michael Shermer, founder of the Skeptics Society and author of “The Believing Brain” writes, “We all support the world we already have.”

Bottom line:
Witton, Hone and Naish don’t like ReptileEvolution.com because it doesn’t support the paleo world they already have. Like Creationists they display the following traits raised by Prothero:

  1. Reduction of cognitive dissonance (= the state of having inconsistent thoughts, beliefs, or attitudes, especially as relating to behavioral decisions and attitude change) when presented with evidence that works against that belief, the new evidence cannot be accepted.
  2. Tribalism = we learn our world from whoever we were raised by. And all three professors are friends of one another.
  3. Deep innate psychological tendencies are genetic = there are some people who readily accept new ideas and there are some people who do not. Unfortunately, all three appear to have the same gene.
  4. Confirmation bias (= the tendency to interpret new evidence as confirmation of one’s existing beliefs or theories.) Thus when Hone and Benton (2007, 2009) come out with the worst paper I have reviewed, Naish and Witton support it anyway.
  5. Cherry picking (= remembering the hits, forgetting the misses). Hone, Witton and Naish like to pick on poor Longisquama, which was difficult, but not impossible to interpret and all three like to ignore the whole point of ReptileEvolution.com, the cladograms, both the large reptile tree and the large pterosaur tree. Note that no other pterosaur worker has produced competing interpretations of Longisquama of equal detail nor competing cladograms that include tiny pterosaurs. In this regard these pterosaur workers are exactly like Dr. Feduccia and the late Dr. Martin (who deny the theropod-bird link and never employ phylogenetic analysis) and also like extant Creationists, who likewise never employ phylogenetic analysis. Remember when Hone and Benton first deleted the taxa that Peters 2000 proposed, then deleted Peters 2000 from the competition? This was cherry picking at its best.
  6. Qiuote mining (= in this case finding images and hypotheses that have been long ago trashed in order to undermine the site. These are essentially ad hominem (directed against a person rather than the position they are maintaining) attacks as they blackwash my methods (which they practice too) and the entire website while they could have gotten specific about one problem or another.
  7. Missing the forest for the trees (= The big picture) is the large reptile tree cladogram. This is created by a huge mass of data and becomes strengthened with every additional taxon – all of which affect every other taxon. In such an analysis you can remove data, remove taxa, remove characters and nothing falls apart. The subsets are just as strong as the dataset itself. But Hone, Naish and Witton refuse to acknowledge that, preferring to continue their thinking that pterosaurs appeared suddenly in the fossil record, like on the fourth day of Creation. Phylogenetic analysis would solve their quandary, if only they would give it a chance.

Dr. Prothero asks: Why is science different?
Prothero answers his own question in this fashion:

  1. Science (like ReptileEvolution.com) is always testing with falsification, prove things wrong, correcting mistakes. Presently I’ve made over 50,000 corrections in drawings and scores and look forward to many more. Getting it right is important.
  2. Science (like ReptileEvolution.com) is always tentative, no claim to final truth. I am always looking for a competing hypothesis. Witton, Hone, Naish, Bennett and other referees are making sure my papers are not getting published. They don’t like it when their claims are disputed here at PterosaurHeresies.
  3. Science (like ReptileEvolution.com) works! It provides answers that make sense, can be replicated, and can provide predictions.
  4. In Science peer review cancels individual biases. Sadly the current pterosaur referees, Hone, Witton, Naish and others, are all from the same school of thought. Every day I hope to change that, to open them up to accept more valid hypotheses that work!
  5. In Science, if you’re not pssing people off, you’re not doing it right. Well, I must be doing something right, because Witton and Naish are never praising my work. It would be great if we could argue about it. I guess we’re doing that here.

Prothero finished with a cartoon
of a professor who was showing his cognitive dissonance: “If P is false, I will be sad. I do not wish to to be sad. Therefore, P is true.”

This is human nature.
We all have it. We all get jealous, ambitious. disappointed. As scientists we have to get over our human nature and let testing and experimentation rise above human nature. We have to be like Galileo, not Aristotle.

References
Bennett SC 1995. A statistical study of Rhamphorhynchus from the Solnhofen limestone of Germany: year classes of a single large species. Journal of Paleontology 69, 569–580.
Lü J, Unwin DM, Jin X, Liu Y and Ji Q 2009. Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull. Proceedings of the Royal Society London B  (DOI 10.1098/rspb.2009.1603.)
Padian K 1983. Osteology and functional morphology of Dimorphodon macronyx (Buckland) (Pterosauria: Rhamphorhynchoidea) based on new material in the Yale Peabody Museum, Postilla, 189: 1-44.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. The origin and radiation of the Pterosauria. Flugsaurier. The Wellnhofer Pterosaur Meeting, Munich 27
Wang X, Kellner AWA, Jiang S, Meng X. 2009. An unusual long-tailed pterosaur with elongated neck from western Liaoning of China. Anais da Academia Brasileira de Ciências 81 (4): 793–812.