Darwin’s finches: Mesozoic style

Originally ‘Darwin’s finches’ =
small birds from the Galápagos Islands west of Ecuador, in the Pacific Ocean.

According to Wikipedia:
The term “Darwin’s finches” was first applied by Percy Lowe in 1936, and popularised in 1947 by David Lack in his book Darwin’s Finches. The most important differences between species are in the size and shape of their beaks, which are highly adapted to different food sources.”

For today’s post, metaphorically speaking, ‘Darwin’s finches’ =
“several variations on a last common ancestor restricted to a small geographic area.”

Similar Mesozoic variations
on a last common ancestor restricted to a small geographic area are also documented in the large reptile tree (LRT) and the large pterosaur tree (LPT). Here (Figs. 1–8), other than Late Cretaceous Pteranodon (Fig. 1), and Middle Jurassic Darwinopterus (Fig. 8), the others (Figs. 2–7), are all known from the Late Jurassic Solnhofen Formation, a lagerstätte representing an archipelago or series of islands, much like today’s Galápagos Islands.

Here
(Figs. 1–8) pictures of closely related taxa tell the story of their own evolution much better than any long-winded explanation. No two are alike. Arrows indicate phylogenetic order.

If you want to know more,
click on each of the images below. When taken to the large image pages at ReptileEvolution.com a small link at the top of each page will take you to one of the species pictured therein. Other links to related taxa are posted on each species’ page.

Pteranodon

Figure 2. The DMNH specimen is in color, nesting between the short crest KS specimen and the long crest AMNH specimen.

Figure 1. The DMNH specimen is in color, nesting between the short crest KS specimen and the long crest AMNH specimen. If you see a female in this diagram, let me know. No two are alike.

Rhamphorhynchus

Figure 2. Rhamphorhynchus specimens to scale. The Lauer Collection specimen would precede the Limhoff specimen on the second row.

Figure 2. Rhamphorhynchus specimens to scale. The Lauer Collection specimen would precede the Limhoff specimen on the second row. No two are alike, but the Vienna specimen is a juvenile of the larger n81 specimen to its right.

Dorygnathus

Figure 8. Click to enlarge. The descendants of Sordes in the Dorygnathus clade and their two clades of pterodactyloid-grade descendants.

Figure 3. Click to enlarge. The descendants of Sordes in the Dorygnathus clade and their two clades of pterodactyloid-grade descendants. No two are alike.

Germanodactylus

Germanodactylus and kin

Figure 4. Click to enlarge. Germanodactylus and kin. No two are alike.

Pterodactylus

The Pterodactylus lineage and mislabeled specimens formerly attributed to this "wastebasket" genus

Figure 5. Click to enlarge. The Pterodactylus lineage (in white) and mislabeled specimens formerly attributed to this “wastebasket” genus (in color boxes). No two are alike.

Scaphognathus

Figure 1. Scaphognathians to scale. Click to enlarge.

Figure 6. Click to enlarge. Only the left three taxa have been identified as Scaphognathus species. Other tiny unnamed specimens are transitional taxa to Pterodactylus or Germanodactylus leading to larger, later taxa. No two are alike.

Archaeopteryx (some of these Solnhofen birds have been renamed)

Figure 3. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale.

Figure 7. Several Solnhofen birds, including Archaeopteryx, compared to Ostromia to scale. No two are alike.

Darwinopterus

Figure 7. Darwinopterus specimens and a few outgroup taxa.

Figure 8. Darwinopterus specimens and a few outgroup taxa. None of these are basal to any pterodactyloid-grade clades. No two are alike. The female (upper right) is associates with an egg.

Unfortunately,
PhDs and other paleo workers who traditionally refuse to trace and reconstruct ‘to scale’ skeletons of taxa under study never get to discover results like these that are only revealed from producing ‘to scale’ graphics like these (Figs. 1–8). Subtleties come through here, en masse, that are lost when looking at individual skeletons in situ one at a time, especially through a microscope, where you don’t get to see ‘the big picture’. Some workers consider such graphics pseudoscience and crankery.

As a result, no other workers
understand or accept the four origins of the pterodactyloid grade arising from phylogenetic miniaturized transitional taxa (Figs. 3, 6) because they omit pertinent tiny and congeneric taxa. Likewise, workers do not yet understand nor accept the radiation of several bird clades having their genesis in Solnhofen basalmost birds. Workers don’t see ‘the big picture’ because of these taxon exclusions.

Rather, too many workers
try to compile a list of specific traits that differentiate one taxon from another. Here we call that, “Pulling a Larry Martin” because it only sometimes leads to greater understanding. The problem is unrelated taxa too often share those same traits by convergence. Here, reconstructions and a confident nesting in the LRT automatically encompass and include ALL the subtle irregularities between taxa that ‘trait seekers’ traditionally overlook.

References

wiki/Darwin’s_finches

Can the LPT identify a pterosaur known only by its palate (and a few cervicals)?

Summary for those in a hurry:
Once the phylogeny of this specimen was determined (after considering all options in the LPT), the stratigraphic age of this specimen turned out to be the real surprise.

Wang et al. 2008
described a 22cm pterosaur skull exposed in palatal view (Fig. 1) from the Early Cretaceous Jiufotang Formation of Liaoning, China. Hongshanopterus lacustris (IVPP V14582) was considered a subadult individual. The robust, triangular teeth were flattened inside and out like those of other istiodactylids, but unlike other istiodactylids, the tooth row extended beyond the first third of the skull and in having some premaxillary teeth curved like sharp hooks.

Figure 1. Hongshanopterus in situ compared to Darwinopterus and Wukongopterus.

Figure 1. Hongshanopterus in situ compared to Darwinopterus and Wukongopterus. Not an istiodactylid, but a wukongipterid. Here all are shown about half life size.

Witton 2012
nested Hongshanopterus in an unresolved clade with Pteranodon, Coloborhynchus and Haopterus.

Kellner et al. 2019 again
nested Hongshanopterus basal to the clade Istiodactylidae.

By contrast
the large pterosaur tree (LPT, 251 taxa) nested Hongshanopterus between the wukongopterids, Wukongopterus and Kupengopterus, far from any istiodactylids. It takes 5 extra steps to force fit Hongshanopterus in the base of the Istiodactylidae (and that’s using just the few characters visible in Hongshanopterus).

That makes Hongshanopterus the largest and latest surviving
wukongopterid (Fig. 2), a clade otherwise restricted to the Middle to Late Jurassic and a clade famous for having a ‘pterodactyloid’-grade skull with a more primitive long-trailed post-crania.

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 2. 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.

A clade member,
Darwinopterus, was considered a transitional taxon leading to pterodactyloid-grade pterosaurs. Adding more taxa, as in the LPT, does not support that hypothesis. At present Darwinopterus is a terminal taxon leaving no descendants. Hongshanopterus is the only wukongopterid (so far) to make it into the Early Cretaceous… and it has the largest skull.

Figure 2. Click to enlarge. Anurognathids to scale. The adult of the IVPP embryo is 8x the size of the embryo, as in all other tested adult/embryo pairings.

Figure 3. Click to enlarge. Anurognathids to scale. The adult of the IVPP embryo is 8x the size of the embryo, as in all other tested adult/embryo pairings.

Only a few basal pterosaurs survived into the Cretaceous.
The giant anurognathid embryo, IVPP V13758  (Fig. 3) is the only other basal pterosaur known at present to survive into the Cretaceous.


References
Kellner AWA et al. (6 co-authors) 2019. First complete pterosaur from the Afro-Arabian continent: insight into pterodactyloid diversity. Nature.com/ScientificReports 9:17875. PDF
Wang X, de Almeida Campos D, Zhou Z and Kellner AWA 2008. A primitive istiodactylid pterosaur (Pterodactyloidea) from the Jiufotang Formation (Early Cretaceous), northeast China. Zootaxa. 1813: 1–18.
Witton MP 2012. “New Insights into the Skull of Istiodactylus latidens (Ornithocheiroidea, Pterodactyloidea)”. PLoS ONE. 7 (3): e33170.

wiki/Hongshanopterus
wiki/Wukongopteridae

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.

SVP 8 – a new wukongopterid from China

In an SVP abstract
Cheng et al. 2015 describe a new wukongopterid, but have several issues to get over.

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 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.

From the abstract – asterisks have replies below:

The Wukongopteridae comprises a group of long-tailed flying reptiles that combine typical characteristics of basal (non-Pterodactyloidea) and derived pterosaurs (Pterodactyloidea)*. To date, it contains three genera: Wukongopterus, Darwinopterus, and Kunpengopterus**, and potentially also includes Changchengopterus***. Although known from several specimens, there is still a general lack of knowledge about their anatomy, particularly changes during ontogeny.**** Here we report a new specimen (IVPP V17959) that can be referred to the Wukongopteridae based on the presence of a confluent nasoantorbital fenestra, elongated cervical vertebrae and a long tail. The skull and lower jaw are preserved laterally and exposed in left view, lacking the rostral tip. The premaxilla bears a low ossified crest, which is confined to the anterior part of premaxilla and possibly extends to the rostral tip. This differs from Wukongopterus, in which the anterior dorsal margin of the premaxilla is flat, Darwinopterus, which shows a bony premaxillary crest starting anterior to the nasoantorbital fenestra reaching the skull roof*****, and Kunpengopterus, which lacks a cranial crest. The nasal bears a ventral process formed by contralateral fusing elements. Although broken, it is clear that this process almost reaches the ventral margin of the nasoantorbital fenestra. This process differs from the short and inclined nasal process of Darwinopterus and Kunpengopterus. The postcranial skeleton of IVPP V17959 shows signs of an ontogenetically fully mature individual at the time of death, having several elements completely fused such as the scapula and coracoid, the proximal and distal carpal series, and the extensor tendon process of the first wing finger phalanx******. Besides that, opposite prepubes are in close contact with the suture between them partially open suggesting that they are about to fuse. Based on this specimen, it appears that the fusion of the prepubes occurs very late in ontogeny. The new specimen also increases the diversity of the Wukongopteridae and the non-pterodactyloid pterosaurs of the Yanliao Biota, suggesting that it was the most abundant pterosaur group represented in that region during the Jurassic.”

*So do anurognathids (just ask Brian Andres).

** The large pterosaur tree also includes Pterorhynchus, Archaeoistiodactylus and Jianchangnathus in that clade, as more basal members.

***Only the referred specimenPMOL-AP00010, not the much smaller holotype, CYGB-0036. which is closer to Sordes..

**** There should be few to no changes during ontogeny as pterosaurs are known to grow (except for their crests) isometrically, which is why many (hatchlings of the crow-sized and larger pterosaurs) can fly upon hatching.

***** Some Darwinopterus do not have a premaxillary crest.

****** Fusion is more dependent on phylogeny, not ontogeny. Remember, these are lepidosaurs.

It is worthwhile to put all wukongopterid specimens into a phylogenetic analysis. There is phylogenetic variety just in Darwinopterus, for example.

References
Cheng X et al. 2015. 
Description of a new wukongopterid pterosaur with a different type of premaxillary crest from the Jurassic of China and its implications for ontogeny. Journal of Vertebrate Paleontology abstracts.

New Painten “Pro-Pterodactyloid”

A new, excellently preserved and unnamed private specimen has been published by Tischlinger and Frey (2013). It comes from the Latest Kimmeridgian of the Jurassic, just before the last age of the Jurassic, the Tithonian. The specimen is owned by a private research institute headed by Birgit Albersdörfer.

Figure 1. The Painten pterosaur (privately owned) from Frey and Tischlinger 2013. Excellent preservation and preparation here.

Figure 1. The Painten pterosaur (privately owned) from Frey and Tischlinger 2013. Excellent preservation and preparation here.

From their abstract: The new specimen provides evidence of a late stage of a gradual evolution from the basal pterosaur construction (the so-called ‚rhamphorhynchoid‘ grade) to a pterodactyloid one. — The Painten pro-pterodactyloid demonstrates the evolutionary pathway towards a pterodactyloid flight configuration, which is characterized by the reduction of the fifth pedal ray (digit), shortening of the tail and the elongation of metacarpal IV with respect to the humerus to more than 70% of the length of the latter.”

Figure 2. Click to enlarge. Painten pterosaur compared to phylogenetic sister taxa. Ornithocephalus and SMNS 81775 are the basal taxa here. Note that while everything else grows on derived taxa, the metacarpus stays the same size. The large size of the Painten pterosaur, along with the greater length of pedal digit 3 and the brevity of the metacarpus sets it apart in its own clade, of which this the first known representative. Larger than its relatives, this is an unlikely juvenile (contra Hone, see below).

Figure 2. Click to enlarge. Painten pterosaur compared to phylogenetic sister taxa. Ornithocephalus and SMNS 81775 are the basal taxa here. Note that while everything else grows on derived taxa, the metacarpus stays the same size. The large size of the Painten pterosaur, along with the greater length of pedal digit 3 and the brevity of the metacarpus sets it apart in its own clade, of which this the first known representative. Larger than its relatives, this is an unlikely juvenile (contra Hone, see below).

Tischlinger and Frey considered the Painten pterosaur “the last step on the long road from a basal pterosaur to the pterodactyloid.” (translated from the original German). They described it thoroughly.

Unfortunately, no phylogenetic analysis was provided.
So I provide one. Placing the Painten pterosaur into the large pterosaur tree nests it as a very basal Pterodactylus, between the very tiny SMNS 81775 specimen and Ningchengopterus, both basal to all valid Pterodactylus genera and all very much within this particular pterodactyloid-grade clade that began several nodes earlier. So the Painten pterosaur is a transitional specimen of sorts (aren’t they all? except for the terminal taxa) but only transitioning between the tiny Scaphognathus descendants and the genus Pterodactylus. Even so, several autapomorphies are present like the presence of a pedal digit 3 longer than pedal digit 2 and a very short prepubis.

The problem is
There are so many pterosaurs that converge on the morphology of Pterodactylus that aren’t really related to Pterodactylus that this genus has become a wastebasket taxon and is need of a big revision. All problems are solved with phylogenetic analysis, but no one, apparently, is interested in doing this.

The other problem is
Because they have not included multiple specimens from single genera and tiny pterosaurs most pterosaur paleontologists are still stuck in the old paradigm that all pterodactyloid-grade pterosaurs had a single common origin creating a monophyletic clade. Phylogenetic analysis shows this is not true. There were four convergent origins for the pterodactyloid grade. This is why the putative Painten transitional taxon looks so different from the putative Darwinopterus transitional taxon. They are not related to one another, but represent different clades. On the same subject from another point-of-view, Tischlinger and Frey hoped to nest their new pterosaur based on the old “rules” about which traits defined a basal pterosaur and which traits defined a pterodactyloid. You can’t do that. That’s putting the cart before the horse. You have to use a phylogenetic analysis and let the data and the analysis tell you how the traits are ordered. The order of longer and shorter traits may be more complex than the old “rules” indicate. They don’t always proceed in a step forward – step forward progress. You have to take what Nature gives you, and not try to pigeonhole new finds into old clades.

The third problem is
The belief in the mosaic pterosaur, one under modular evolution in which some body parts are advanced while others are not. Again, this is an illusion based on two few taxa in the analysis.

Let’s look at the Painten pterosaur in more detail.

Figure 4. The feet and tail of the Painten pterosaur with colors applied to bones. One loose proximal tail bone (red) is displaced at left. Left manual 4.4 is broken and re-healed in a jagged fashion. The wing tips are large, pulley-like joints. The wing unguals (dark blue) are displaced.

Figure 4. The feet and tail of the Painten pterosaur with colors applied to bones. One loose proximal tail bone (red) is displaced at left. Left manual 4.4 is broken and re-healed in a jagged fashion. The wing tips are large, pulley-like joints. The wing unguals (dark blue) are displaced.

Pedal digit 5 is rarely so wonderfully preserved (Fig. 3). Note the distal tip of p5.2. It has a joint surface, but the next phalanx, the ungual, is not readily observable.

However, if we take a closer look the ungual is there on both feet (Fig. 4), on edge on the left foot and flattened on top of mt5 on the right foot. Along the same lines the wingtips (m4.4) appear to also have joint surfaces, but no unguals. The left ungual has been displaced and now appears at mid phalanx of m4.4. The right ungual is nowhere to be seen, perhaps as a result of the breakage of the phalanx, or simple taphonomy or burial.

Tischlinger and Frey note that pedal digit 5 could be used for “tensioning the tail wing membrane (uropatagium), but to a very limited extent.” Unfortunately only one specimen has been promoted to link pedal digit 5 to the uropatagium, the holotype of Sordes, and that is a misidentification. No pterosaurs link pedal digit 5 to the uropatagium, but Sharovipteryx does.

Figure 3. The wrist of the Painten pterosaur. Here the vestige of manual digit 5 (blue) is clearly visible on the palmar side of the left wrist.

Figure 5. The wrist of the Painten pterosaur. Here the vestige of manual digit 5 (blue) is clearly visible on the palmar side of the left wrist.

Manual digit 5 is usually disturbed during taphonomy.
Here it is (in dark blue) undisturbed, but curled, on an axially rotated metacarpus. The undisturbed pteroid is articulated to the radiale. The extensor tendon process is not coosified to m4.1. The fingers are all rotated into the plane of the substrate. In vivo they would have pointed palmar side down, as in other tetrapods.

Transitional?
Tischlinger and Frey agree with the Darwinopterus transitional hypothesis, which is falsified when more taxa are included in analysis. They consider the Painten pterosaur, with it’s short tail and short pedal digit 5, to be the next step from Darwinopterus toward the pterodactyloid grade. These are traits that Darwinopterus had not acquired.

If you think the consensus is correct on this issue, remind yourself that Tischlinger and Frey merely accepted the findings of others, despite the red flags and oddities. I test issues using established methods, like phylogenetic analysis. I don’t have to make up excuses for data or imagine the evolution of body plans because all that comes from the order of the nodes in the recovered trees.

That’s good Science, right? Repeat the experiment if you don’t agree, then let me know if you come up with something different.

Tischlinger and Frey discuss various ways or paths by which the rhamph body plan evolved to become the pterodac body plan, but this is all simple dreaming without a large phylogenetic analysis of the Pterosauria. This the -only- method by which you can actually trace the appearance and subsequent modification of the various traits in much greater resolution, precision and verifiable validity.

Finally, if Rhamphodactylus, Darwinopterus and the Painten pterosaur were indeed phylogenetic sisters representing closely related steps in the evolution of the pterodactyloid grade, shouldn’t they look more alike (Fig. 5)? Phylogenetic analysis indicates they were not related, only convergent.

Figure 5. The Painten pterosaur, Darwinopterus and "Rhamphodactylus" to scale showing their variety and their transitional status.

Figure 5. Three putative transitional pterosaurs. The Painten pterosaur, Darwinopterus and “Rhamphodactylus” to scale showing their variety and transitional status. These three are not related to one another, but acquired similar traits by convergence.

The Painten pterosaur is still very special
The Painten pterosaur is a transitional taxon leading to higher Pterodactylus specimens. It also represents a new clade in the pterosaur bush that had its own traits. Unlike other sister taxa pedal digit 5 is longer than the others. The middle dorsal vertebrae are compressed to be much shorter than the anterior and posterior verts, creating a shorter torso. The prepubis is remarkably tiny. The teeth are more needle-like than those of others.  Pedal digit 5 is more robust than in sister taxa.

Postscript
Dave Hone in his Archosaur Musings Blogpost described the Painten pterosaur as a “small, juvenile animal.” He did not say why, or to which adult it would be most closely associated. Hone may have followed the old paradigm that states a large orbit and unfused extensor tendon process are juvenile traits. He may not be aware that phylogenetic analysis (the large pterosaur tree) demonstrates that both are phylogenetic, rather than ontogenetic in nature.

Hone reported, “The fifth toe also seems to be something of an intermediate – it is not a small nub like the pterodactyloids, but nor is the second phalanx that long and it’s not curved either as in other basal forms.” Evidently he was not aware of the many pterodactyloids with longer lateral toes, often tucked beneath the other four. The relative shortness of metacarpal 4 was noted by both Tischlinger and Frey and Hone which they considered intermediate trait between shorter rhamphs and longer pterodacs. Unfortunately that assumes linear progression in evolution, which is not born out when phylogenetic analysis shows that more basal taxa had relatively longer metacarpals. We have to avoid wishful thinking and rigorously test all such “eyeball” assumptions.

References
Tischlinger H and Frey E 2013.  Ein neuer Pterosaurier mit Mosaikmerkmalen basaler und pterodactyloider Pterosauria aus dem Ober-Kimmeridgium von Painten (Oberpfalz, Deutschland) — A new pterosaur with mosaic characters of basal and pterodactyloid pterosauria from the Upper Kimmeridgian of Painten (Upper Palatinate, Germany) Archaeopteryx 31:1-13.

About that Darwinopterus naris

Some of the Darwinopterus skulls are pretty busted up. This one is nearly pristine: Darwinopterus robustodens (HGM 411HIII-0309A, Lü et al. 2011a). They say the naris is absent or confluent with the antorbital fenestra in this specimen and all wukongopterids.

Let’s see if that’s true.

Figure 1. A careful tracing in color of the skull of Darwinopterus clearly reveals the naris, here with a portion of the broken premaxillary crest having slid behind it.

Figure 1. Click to enlarge. The original tracing (b&w below) did not identify a naris. A careful tracing in color of the skull of Darwinopterus clearly reveals the naris, here with a portion of the broken premaxillary crest having slid behind it. Restoring that part more clearly reveals the naris present. On a side note, the lacrimal is not as large as originally pictured. I’ve never seen a lacrimal roofing the skull, nor have I seen a nasal absent from the skull roof. The quadrate also has some issues. And then you have to ask, what was this clade doing with those giant hyoids? Did it have a giant tongue? or dewlap?

The naris has been overlooked or ignored far too often in many pterosaurs. Here is one more example. And a nice example of how DGS (plus a little experience and reconstructions) can find details that are otherwise overlooked.

Figure 6. Darwinopterus robustodens at the Henan Geological Museum (41HIII-0309A). The teeth tips are described (Lü et al. 2011) as sharper and are swollen between the crown and root. There are nine tooth pairs in the upper and eleven in the lower jaws, which are smaller than in D. modularis.

Figure 2. Darwinopterus robustodens at the Henan Geological Museum (HGM 41HIII-0309A). The naris is clearly present. The reconstruction and phylogenetic analysis are part of the DGS process.

Reference
Lü J, Xu L, Chang H and Zhang X 2011b. A new darwinopterid pterosaur from the Middle Jurassic of Western Liaoning, northeastern China and its ecological implicaitions. Acta Geologica Sinica 85: 507-514.

Darwinopterus: 5 specimens in phylogenetic analysis – part 2

Figure 2. Subset of the large pterosaur tree showing relationships among Darwinopterus and its predecessors among the Wukongopteridae and their predecessors.

Figure 1. Subset of the large pterosaur tree showing relationships among Darwinopterus and its predecessors among the Wukongopteridae and their predecessors.

Yesterday we looked at the phylogenetic ancestors (Fig. 1) of Darwinopterus. Today we’ll take a closer look at the five specimens assigned to this genus.

Lü et al. (2011) noted the alveoli have raised margins, the nasoantorbital fenestra were confluent [not true, if you look closely], inclined quadrate [plesiomorphic], elongate cervical vertebrae with low neural spine and reduced or absent cervical ribs [plesiomorphic], long tail of more than 20 caudals partially enclosed by filiform extensions of the pre- and post-zygopophyses [plesiomorphic] short metacarpus less than 60 percent length of humerus [plesiomorphic] fifth toe with two elongate phalanges [plesiomorphic] and curved second pedal phalanx with the angle of 130 degrees [plesiomorphic].

In the current analysis
the following traits distinguish Darwinopterus from outgroup taxa: Some are equivocal, subject to a change of score by virtue of taphonomic changes and exposure. Only the first two dorsal ribs are robust, not the first three. The humerus shape is straighter. The deltopectoral crest is wider than deep. Manual 1.1 is shorter relative to m2.1. Manual digit 3 is not longer than mt4. The prepubis is putter-shaped. So, really not much. Only 5 steps are added when the outgroup taxa are moved inside the clade.

The most basal taxon
is the female, ZMNH M8802 (Fig. 2) which is crestless, like its ancestors. The mandible tip is bent down.

Figure 2. Darwinoperus ZMNH8802 specimen, the female and most basal member of this genus.

Figure 2. Darwinoperus ZMNH8802 specimen, the female and most basal member of this genus.

On a side note:
The original ischium (Fig. 2a) was misidentified. It is hard to see on top of the right femur (on the left below as seen in ventral view). What was originally identified as a deep left ischium by Lü et al. is instead a second prepubis, identical to the correctly identified prepubis on the opposite side (Fig. 2a, b)

Figure 2a. Original identification by Lü et al. 2011a) of puboischium in Darwinopterus.

Figure 2a. Original identification by Lü et al. 2011a) of puboischium in Darwinopterus.

xx

Figure 2b. Darwinopterus female pelvis (ZMNH 8802) with pelvic bones correctly identified. the ischium is best seen on the left in indigo. The prepubes are red.

Figure 2b. Darwinopterus female pelvis (ZMNH 8802) with pelvic bones correctly identified. the ischium is best seen on the left in indigo. The prepubes are red. The egg has been flattened and deflated, like a balloon. The paired ischia are still deep enough to pass the egg in vivo.

The other four specimens have crests. The other four specimens have a shorter prepubis relative to the pelvis. Again, not much separates them.

The next clade
has two similar members, D. linglongtaensis (Fig. 3) and the YH2000 specimen (Fig. 4). Both are relatively gracile. The orbit is more upright. The mandible is gracile and slightly bent up distally. Some dentary teeth are taller than the mandible. The sacrum is mostly fused. The torso is longer relative to the humerus, separating the elbow from the ilium. The humerus is subequal to the femur. The ulna is longer relative to the humerus. Manual 2.1 and m3.1 are subequal. Manual 3.3 ≥ m3.1 + m3.2. When folded manual 4.1 extends only to the distal ulna, not the half point. Metatarsals 1 and 2 are the longest. Pedal 4.4 is shorter than p4.1.

Figure 3. Darwinopterus YH2000 specimen.

Figure 3. Darwinopterus YH2000 specimen. It has a shorter ilium and a gracile build.

Minor differences, getting into the range of individual variation, separate the YH2000 and IVPP V 16049 specimens. The latter is more robust with a longer ilium and a shorter p5.1.

Figure 4. Darwinopterus linglongtaensis.

Figure 4. Darwinopterus linglongtaensis, IVPP V 16049. This is a robust specimen.

The third clade
has larger members, the Darwinopterus modulars holotype (ZMNH 8782, Fig. 5) and D. robustodens (41HIII-0309A, Fig. 6). The postorbital bar is lower and more robust. The coracoid is less than half the length of the humerus. The humerus is longer relative to the torso. The pubis depth is not shorter than the ischium.

Figure 5. Darwinopterus ZMNH 8782. A taller specimen with a longer neck and larger skull.

Figure 5. Darwinopterus modularis (holotype) ZMNH 8782. A taller specimen with a longer neck and larger skull.

Again, minor differences separate these two, including the length of the neck, distribution of the teeth, a more robust tail in the holotype, and the pelvis shape.

Figure 6. Darwinopterus robustodens at the Henan Geological Museum (41HIII-0309A). The teeth tips are described (Lü et al. 2011) as sharper and are swollen between the crown and root. There are nine tooth pairs in the upper and eleven in the lower jaws, which are smaller than in D. modularis.

Figure 6. Darwinopterus robustodens at the Henan Geological Museum (41HIII-0309A). The teeth tips are described (Lü et al. 2011) as sharper and are swollen between the crown and root. There are nine tooth pairs in the upper and eleven in the lower jaws, which are smaller than in D. modulars. Tomorrow we’ll take a closer look at the naris.

If we concentrate only the feet
We find a gradual evolution and a resulting variety in the pes of the included taxa (Fig. 7). Note the variation in p5.1 vs. mt4, the longest toe from the heel, the variety in metatarsal lengths and the relative lengths of metatarsus to digits.

Figure 6. Darwinopterus feet. If the gracile forms were female, would they have phylogenetically different feet? Or is it more parsimonious to consider the morphologically different forms a clade?

Figure 7. Darwinopterus feet. If the gracile forms were female, would they have phylogenetically different feet? Or is it more parsimonious to consider the morphologically different forms a clade?

The wukongopterids were an interesting clade, evolving some pterodactyloid-grade traits, but not others. The multiple origin of the pterodactyloid-grade is a subject we handled earlier here. If you want to see all the wukongopterids together to scale, click here

References
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.)
Lü J, Unwin DM, Deeming DC, Jin X, Liu Y and Ji Q 2011a. An egg-adult association, gender, and reproduction in pterosaurs. Science, 331(6015): 321-324. doi:10.1126/science.1197323
Lü J, Xu L, Chang H and Zhang X 2011b. A new darwinopterid pterosaur from the Middle Jurassic of Western Liaoning, northeastern China and its ecological implicaitions. Acta Geologica Sinica 85: 507-514.
Lü J-C and Fucha X-H 2010. A new pterosaur (Pterosauria) from Middle Jurassic Tiaojishan Formation of western Liaoning, China. Global Geology 13 (3/4): 113–118. doi:10.3969/j.issn.1673-9736.2010.03/04.01.
Martill DM and Etches E 2012. A new monofenestratan pterosaur from the Kimmeridge Clay Formation (Upper Jurassic, Kimmeridgian) of Dorset, England. Acta Palaeontologica Polonica. in press. doi:10.4202/app.2011.0071.
Wang X, Kellner AWA, Jiang S-X, Cheng X, Meng Xi & Rodrigues T 2010. New long-tailed pterosaurs (Wukongopteridae) from western Liaoning, China. Anais da Academia Brasileira de Ciências 82 (4): 1045–1062.
Wang X-L, Kellner AWA, Jiang S-S, Cheng X, Meng X and Rodriques T 2014. New long-tailed pterosaurs (Wukongopteridae) from western Liaoning, China. Anais da Academia Brasileira de Ciências (2010) 82(4): 1045-1062.
Zhou C-F and Schoch RR 2011. New material of the non-pterodactyloid pterosaur Changchengopterus pani LÜ, 2009 from the Late Jurassic Tiaojishan Formation of western Liaoning. N. Jb. Geol. Paläont. Abh. 260/3, 265–275 published online March 2011.

wiki/Kunpengopterus
wiki/Darwinopterus

Darwinopterus: 5 specimens in phylogenetic analysis – part 1

Earlier we looked at Darwinopterus, of which several specimens (Figs. 1,2) are now known. When the female with the associated egg was found (Lü et al. 2011a) they proposed that some of the differences (pelvis shape, rostral crest, size) could be attributed to gender.

We learned earlier that this would be a unique situation among pterosaurs as all other such candidates for this difference do not indicate gender, but phylogeny when placed under analysis (small crests are derived from no crests and small crests give rise to large crests, for instance). What Lü et al. considered a deep ischium in the female was found to be a deep prepubis here.

Like Pteranodon, Rhamphorhynchus, Pterodactylus, Germanodactylus and other genera, I added the five specimens attributed to Darwinopterus (Fig. 1) to the large pterosaur tree to see how they might be related to one another in a first ever phylogenetic analysis of this genus (Fig. 2).

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 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. The odd throat sac of Pterorhynchus may represent a normal throat ripped away from its base.

Figure 2. Subset of the large pterosaur tree showing relationships among Darwinopterus and its predecessors among the Wukongopteridae and their predecessors.

Figure 2. Subset of the large pterosaur tree showing relationships among Darwinopterus and its predecessors among the Wukongopteridae and their predecessors.

To give some perspective
Jianchangnathus, at the base of this subset of the large pterosaur tree, also nested between basal Dorygnathus and Scaphognathus. No taxa succeed Darwinopterus. It was a sterile lineage, not a transitional taxon.

Note the very small naris and relatively large skull on Jianchangnathus. More derived taxa, including Darwinopterus, had a skull that was just as long, just not as tall, thereby reducing its weight. So this clade did not have a longer skull than sister taxa.

All more derived taxa, including Darwinopterus, also had a reduced to absent naris. So this is the genesis of that trait.

The long neck of wukongopterids also had its genesis in more basal taxa, like the PMOL specimen attributed to Changchengopterus by Zhou and Shoch 2011.

Earlier we noted the relationship of Pterorhynchus to the wukongopterids. And recently we noted that the new specimen referred to Changchengopterus (Zhou and Schoch 2011) actually nests at the base of the Wukonopteridae, far from the the holotype Changchengopterus, which is half the size.

Kunpengopterus now has a sister taxon in Archaeoistiodactylus (Lü and Fucha 2010) which Martill and Etches (2012) correctly referred to this clade.

Tomorrow we’ll look at the five specimens of Darwinopterus a little more closely.

References
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.)
Lü J, Unwin DM, Deeming DC, Jin X, Liu Y and Ji Q 2011a. An egg-adult association, gender, and reproduction in pterosaurs. Science, 331(6015): 321-324. doi:10.1126/science.1197323
Lü J, Xu L, Chang H and Zhang X 2011b. A new darwinopterid pterosaur from the Middle Jurassic of Western Liaoning, northeastern China and its ecological implicaitions. Acta Geologica Sinica 85: 507-514.
Lü J-C and Fucha X-H 2010. A new pterosaur (Pterosauria) from Middle Jurassic Tiaojishan Formation of western Liaoning, China. Global Geology 13 (3/4): 113–118. doi:10.3969/j.issn.1673-9736.2010.03/04.01.
Martill DM and Etches E 2012. A new monofenestratan pterosaur from the Kimmeridge Clay Formation (Upper Jurassic, Kimmeridgian) of Dorset, England. Acta Palaeontologica Polonica. in press. doi:10.4202/app.2011.0071.
Wang X, Kellner AWA, Jiang S-X, Cheng X, Meng Xi & Rodrigues T 2010. New long-tailed pterosaurs (Wukongopteridae) from western Liaoning, China. Anais da Academia Brasileira de Ciências 82 (4): 1045–1062.
Wang X-L, Kellner AWA, Jiang S-S, Cheng X, Meng X and Rodriques T 2014. New long-tailed pterosaurs (Wukongopteridae) from western Liaoning, China. Anais da Academia Brasileira de Ciências (2010) 82(4): 1045-1062.
Zhou C-F and Schoch RR 2011. New material of the non-pterodactyloid pterosaur Changchengopterus pani LÜ, 2009 from the Late Jurassic Tiaojishan Formation of western Liaoning. N. Jb. Geol. Paläont. Abh. 260/3, 265–275 published online March 2011.

wiki/Kunpengopterus
wiki/Darwinopterus

Revision to earlier mistake on Darwinopterus pelvis

Earlier I misinterpreted the pelvis and prepubis of Darwinopterus robustodens (since revised). Here (Figs. 1-5) I want to take you through the DGS process that more accurately identifies the elements present. Here (Fig. 1) is the in situ fossil. The original reconstruction, you might recall (Fig. 5) found a very deep pubis and a very shallow ischium opening, hardly enough to squirt out a turd, let along an egg!

Figure 1. The pelvic area of Darwinopterus robustodens in situ.

Figure 1. The pelvic area of Darwinopterus robustodens in situ. The ilium is easy to see. The ventral pelvis can be confusing at first glance. Here’s where DGS really shines.

First we’ll colorized the sacral verts (Fig. 2).

Figure 2. Darwinopterus robustodens sacral vertebrae in red.

Figure 2. Darwinopterus robustodens sacral vertebrae in red.

Then we’ll find the left and right pelvic and prepubic elements (Fig. 3). Note how the rear prepubis provides the illusion of a continuous ventral pelvic rim. The left pubis is folded back onto the medial left ischium, thickening it. Compared to other Darwinopterus specimens, the prepubes are flipped here.

Figure 3. Darwinopterus robustodens pelvic and prepubis elements. Note the left pubis is folded back on top of the left ischium. The rear prepubis fills a nice gap that makes the elements look like a single element.

Figure 3. Darwinopterus robustodens pelvic and prepubis elements. Note the left pubis is folded back on top of the left ischium. The rear prepubis fills a nice gap that makes the elements look like a single element.

Finally, we’ll colorize the two femora.

Figure 4. The two femurs of Darwinopterus robustodens

Figure 4. The two femurs of Darwinopterus robustodens

Pulling the elements out of the tracings (Fig. 5) provides a more plesiomorphic pelvis with an ischial opening large enough to pass a Darwinopterus-size egg.

Figure 5. Darwinopterus robustodens pelvis as originally reconstructed (gray scale) and as recovered using DGS (color).

Figure 5. Darwinopterus robustodens pelvis as originally reconstructed (gray scale) and as recovered using DGS (color). I wonder whether the present orientation of the prepubis is correct. but it seems to fit better both here and to match with sister taxa when flipped like this.

Cleaning up mistakes is the process of Science.

References
Hyder ES, Witton MP and Martill DM 201X. Evolution of the pterosaur pelvis. Acta Palaeontologica Polonica 5X (X): xxx-xxx. http://dx.doi.org/10.4202/app.2011.1109

Wukongopterus – with a broken leg

Pterosaur fossils can get pretty messed up over 150 million years. Most of that happens during their lifetime or shortly thereafter as they sink into sediments.

Wukongopterus (IVPP V15113 , Wang et al. 2009) is a not-quite complete specimen that preserves a broken leg (Fig. 1). The Daohugou Bed of the Tiaojishan Formation was originally described as Early Cretaceous, but is now dated to the Middle/Late Jurassic boundary. This makes more sense with regard to phylogenetic order.

Figure 1. Wukongopterus with a broken tibia (in pink).

Figure 1. Wukongopterus with a broken tibia (in pink). It looks like the tibia was kept in place by tendons and dermis after the break, whether before or after death. Compare the broken tibia to the unbroken one. Even the foot was twisted medial to lateral.

References

Wang X, Kellner AWA, Jiang S and 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.

wiki/Wukongopterus