The larger specimen of Sinopterus atavismus enters the LPT basal to dsungaripterids

Many pterosaur fossils attributed to Sinopterus
have been described. They vary greatly in size and shape.

Presently four Sinopterus specimens have been added
to the large pterosaur tree (LPT, 253 taxa). They are all sister taxa, but as in Archaeopteryx, no two are alike, one is basal to the others, which are, in turn, basal to large clades within the Tapejaridae.

  1. Sinopterus dongi (the holotype) nests basal to the Tupuxuara clade.
  2. Sinopterus liui nests in the Tupuxuara clade.
  3. Sinopterus jii (aka Huaxiapterus jii) nests basal to the Tapejara clade.
  4. Sinopterus atavisms (Figs. 1-4; Zhang et al. 2019; IVPP V 23388) nests basal to the Dsungaripterus (Fig. 4) clade, outside the Tapejaridae.
Figure 1. Sinopterus atavismus in situ.

Figure 1. Sinopterus atavismus in situ. IVPP V 23388

From the Zhang et al. 2019 abstract:
“Here, we report on a new juvenile specimen of Sinopterus atavismus from the Jiufotang Formation of western Liaoning, China, and revise the diagnosis of this species.”

Zhang et al. note that several elements are unfused including a humeral epiphysis. Several pits and grooves in the distal ends of the long bones are also pitted and grooved. Normally these would be good indicators in archosaurs and mammals, but pterosaurs are lepidosaurs and lepidosaurs follow distinctly different ‘rules’ for growth (Maisano 2002). As an example, some pterosaur embryos have fused elements. Some giant pterosaurs have unfused elements. Here the new specimen (IVPP 23388) is considered an ontogenetic adult as its size is similar to other phylogenetic relatives.

“Sinopterus atavismus does not present a square-like crest. Moreover the feature that groove in the ventral part of the second or third phalanx of manual digit IV is not diagnostic of the species.”

Zhang et al. are comparing the new larger IVPP specimen to the smaller, previously described (Lü et al. 2016) XHPM 1009 specimen (then named Huaxiapterus atavismus), which they considered conspecific. The XHPM specimen has wing phalanx grooves while the IVPP specimen does not. The shapes of the skulls do not match (Fig. 3) and we know that pterosaurs grew isometrically. Thus these two specimens are not conspecific.

“In the new material, the skull preserves a pointed process in the middle part of the dorsal marginof the premaxillary crest, which is different from other Chinese tapejarids. Considering the new specimen is known from a large skeleton that differed from the holotype, this difference may be related to ontogeny, as the premaxillary crest of the holotype is short and does not extend as long as that of the new specimen.”

These two specimens are not conspecific, so ontogenetic comparisons should not be made.

Figure 2. Sinopterus atavismus reconstruction.

Figure 2. Sinopterus atavismus reconstruction.

From the Zhang et al. 2019 discussion:
“Except for D 2525 which represents an adult individual of Sinopterus (Lü et al. 2006b), all Chinese tapejarid pterosaurs known so far were immature individuals at the time of death. The new specimen (IVPP 23388) shares some features with the holotype of Sinopterus atavismus. The wingspan of the new material is about twice as long as that of the holotype of S. atavismus.”

As mentioned above, the IVPP V 23388 specimen is here considered an adult with unfused bone elements. It needs both a new generic and specific name. The XHPM 1009 specimen (Fig. 3) requires further study.

Figure 3. Sinopterus atavismus size comparison

Figure 3. Sinopterus atavismus size and shape comparison.

The present confusion about the ontogenetic status of pterosaurs 
could have been largely resolved with the publication of “The first juvenile Rhamphorhynchus recovered by phylogenetic analysis” and other papers suppressed by pterosaur referees. Sorry, readers, we’ll have to forge ahead with the venues we have.

Figure 3. Sinopterus atavismus skull restored (gray areas).

Figure 4. Sinopterus atavismus skull restored (gray areas).

Figure 4. Sinopterus atavisms compared to Dsungaripterus to scale.

Figure 5. Sinopterus atavisms compared to Dsungaripterus to scale.

Sinopterus atavismus (Zhang et al. 2019; Early Cretaceous; IVPP V 23388) was originally considered a juvenile member of the Tapejaridae, but here nests as a small adult basal to Dsungaripteridae. The antorbital fenestra is not taller than the orbit. The carpals are not fused. No notarium is present. The antebrachium is robust. The distant pedal phalanges are longer than the proximal pedal phalanges. An internal egg appears to be present (but half-final-size adults were sexually mature according to Chinsamy et al. 2008,)

Sinopterus dongi IVPP V13363 (Wang and Zhou 2003) wingspan 1.2 m, 17 cm skull length, was linked to Tapejara upon its discovery, but is closer to Tupuxuara.

Sinopterus? liui (Meng 2015; IVPP 14188) is represented by a virtually complete and articulated specimen attributed to Sinopterus, but nests here at the base of Tupuxuara longicristatus.

Sinopterus jii (originally Huaxiapterus jii, Lü and Yuan 2005; GMN-03-11-001; Early Cretaceous) is basal to the Tapejara in the LPT, distinct from the other sinopterids basal to Tupuxuara.

Figure 5. Click to enlarge. The Tapejaridae arise from dsungaripterids and germanodactylids.

Figure 5. Click to enlarge. The Tapejaridae arise from dsungaripterids and germanodactylids.

The present LPT hypothesis of interrelationships
appears to be a novel due to taxon inclusion, reconstruction and phylogenetic analysis. If not novel, please let me know so I can promote the prior citation.

Traditional phylogenies falsely link azhdarchids with tapejarids
in an invalid clade ‘Azhdarchoidea‘. The LPT has never supported this clade (also see Peters 2007), which is based on one character: an antorbital fenestra taller than the orbit (that a few sinopterids lack). Pterosaur workers have been “Pulling a Larry Martin” by counting on this one character and by excluding pertinent taxa that would have shown them this is a convergent trait ever since the first cladograms appeared in Kellner 2003 and Unwin 2003.

Figure 1. Gene studies link swifts to hummingbirds. Trait studies link swifts to owlets. Trait studies link hummingbirds to stilts.

Figure x. Gene studies link swifts to hummingbirds. Trait studies link swifts to owlets. Trait studies link hummingbirds to stilts.

Unrelated update:
The stilt, Himantopus (Fig. x) has moved one node over and now nests closer to the hummingbird, Archilochus. Both arise from the Eocene bird, Eocypselus, which also gives rise to the hovering seagull, Chroicocephalus. The long, mud probing beak of the stilt was adapted to probing flowers in the hummingbird. All these taxa nested close together in the LRT earlier.


References
Chinsamy A, Codorniú L and Chiappe LM 2008. Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guinazui. Biology Letters, 4: 282-285.
Kellner AWA 2003. 
Pterosaur phylogeny and comments on the evolutionary history of the group. Geological Society Special Publications 217: 105-137.
Lü J and Yuan C 2005. 
New tapejarid pterosaur from Western Liaoning, China. Acta Geologica Sinica. 79 (4): 453–458.
Maisano JA 2002. The potential utility of postnatal skeletal developmental patterns in squamate phylogenetics. Journal of Vertebrate Paleontology 22:82A.
Maisano JA 2002.
Terminal fusions of skeletal elements as indicators of maturity in squamates. Journal of Vertebrae Paleontology 22: 268–275.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Unwin DM 2003. On the phylogeny and evolutionary history of pterosaurs. Pp. 139-190. in Buffetaut, E. & Mazin, J.-M., (eds.) (2003). Evolution and Palaeobiology of Pterosaurs. Geological Society of London, Special Publications 217, London, 1-347.
Wang X and Zhou Z 2003. A new pterosaur (Pterodactyloidea, Tapejaridae) from the Early Cretaceous Jiufotang Formation of western Liaoning, China and its implications for biostratigraphy. Chinese Science Bulletin 48:16-23.
Zhang X, Jiang S, Cheng X and Wang X 2019. New material of Sinopterus (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota of China. Anais da Academia Brasileira de Ciencias 91(2):e20180756. DOI 10.1590/0001-3765201920180756.

wiki/Sinopterus

From Berkeley: pterosaur origins and whale evograms

Professor Kevin Padian (U of California, Berkeley)
has been a champion for evolution over the past several decades. In the 1980s I became acquainted with him when he was the science expert for my first book, Giants.

The following one hour video on YouTube caught my eye.
Professor Padian brilliantly discusses how school districts dealt with invading Creationists. Padian has been leading the charge on many fronts regarding evolution. Unfortunately, he has stayed in his tent sipping tea regarding the origin of flight in pterosaurs (Padian 1985), and the origin of whales, as you’ll see below.

 

From the Berkeley.edu page on pterosaur flight:
“Pterosaurs are thought to be derived from a bipedal, cursorial (running) archosaur similar to Scleromochlus in the late Triassic period (about 225 million years ago). Other phylogenetic hypotheses have been proposed, but not in the context of flight origins. The early history of pterosaurs is not yet fully understood because of their poor fossil record in the Triassic period. We can infer that the origin of flight in pterosaurs fits the “ground up” evolutionary scenario, supported by the fact that pterosaurs had no evident arboreal adaptations. Some researchers have proposed that the first pterosaurs were bipedal or quadrupedal arboreal gliders, but these hypotheses do not incorporate a robust phylogenetic and functional basis. The issue is not yet closed.”

This comes 20 years after Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama (Fig. 1) were added to four previously published phylogenetic analyses and all nested closer to pterosaurs than any tested archosaur (Peters 2000). Aspects of this topic were reviewed here in 2011 and here in 2015.

pterosaur wings

Figure 2. Click to enlarge. The origin of the pterosaur wing from Huehuecuetzpalli (B) to Cosesaurus (C) to Sharovipteryx (D) to Longisquama (E) to the basal pterosaur, Bergamodactylus (F and G).

The same webpage notes:
“Pterosaurs also had a bone unique to their clade. It is called the pteroid bone, and it pointed from the pterosaur’s wrist towards the shoulder, supporting part of the wing membrane. Such a novel structure is rare among vertebrates, and noteworthy; new bones are unusual structures to evolve — evolution usually co-opts bones from old functions and structures to new functions and structures rather than “reinventing the wheel.”

This comes 11 years after Peters 2009 showed the pteroid was not unique, but a centralia that had migratred medially in Cosesaurus (like the panda’s ‘thumb’). Likewise, the not-so-unique pteroid was co-opted from old functions, contra the Berkeley evolution page.

The same webpage notes:
“Pterosaurs had other morphological adaptations for flight, such as a keeled sternum for the attachment of flight muscles, a short and stout humerus (the first arm bone), and hollow but strong limb and skull bones.”

We’ve known since Wild 1993 that what Padian 1985 called a keeled sternum is actually a sternal complex composed of a fused interclavicle + clavicle + single lepidosaur sternum (Fig. 3) after migration over the interclavicle.

Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.

Figure 3. Tritosaur pectoral girdles demonstrating the evolution and migration of the sternal elements to produce a sternal complex.

Backstory…
25 years ago, when I first met Kevin Padian and Chris Bennett, they both impressed upon me, at the same time and during a single conversation, the need for a proper phylogenetic context before making any sort of paleontological hypothesis. That’s when MacClade and PAUP were still ‘newish’. That’s why you might find it ironic that neither Padian nor Bennett have ever tested the addition of the four key taxa in figure 3 to prior published analyses that included pterosaurs, as I did in Peters 2000.

On the second topic of whale evolution:
Padian’s ‘evogram’ (evolution diagram) simply lacks a few key taxa. Odontocetes don’t arise from hippos. Only mysticetes do. Here (Fig. 4) a few missing transitional taxa are added to the existing evogram. Likewise the outgroup for Pakicetus and Indohyus now include overlooked tenrecs and leptictids. They look more like Indohyus than the hippo because microevolution becomes more apparent when pertinent taxa are added. Otherwise it’s a big morphological jump from hippos to Indohyus. Adding taxa makes ‘the jump’ much smaller as the LRT has demonstrated dozens of times. No one should be afraid to simply add taxa.

Figure w. Whale evogram from Berkeley website and what happens when you add taxa based on the LRT.

Figure 4. Whale evogram from Berkeley website and what happens when you add taxa based on the LRT. Two frames change every 5 seconds. It’s not good that the outgroup to the slender Indohyus is the massive Hippopotamus. Frame two repairs that inconsistency with a little microevolution.

As you can see,
the University of California at Berkeley no longer stands at the vanguard of paleontology. Rather it has been promoting traditional myths on its website for the last twenty years.

According to Padian’s online talk (above):
“Just because you have  a degree in science does not mean you’re a scientist. Scientists are people who do research, publish peer-reviewed research as a main part of their living.”

That’s good to know. Of course, it doesn’t help if one suffers from the curse of Cassandra. On that point, I’m not asking anyone to ‘believe the LRT’, but to simply add taxa to your own favorite cladograms, as Peters 2000 did to four different previously published studies that each had their own taxon and character lists. That’s what the large reptile tree has continued to do over the last 9 years. Others who have added taxa and recovered results confirming those recovered by the LRT are listed here. The pair of PhDs who decided those results should be erased are listed here.

Ingroup scientists who attempt to exclude outgroup scientists is a common thread in human history. Here’s a YouTube video trailer for an upcoming Marie Curie biography. I’m sure you all know the story of her pioneering work in radioactive elements.

References
Padian K 1985. The origins and aerodynamics of flight in extinct vertebrates. Palaeontology 28(3):413–433.
Peters D 1989. Giants of Land, Sea and Air — Past and Present. Alfred A. Knopf/Sierra Club Books
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2009.
A reinterpretation of pteroid articulation in pterosaurs.
Journal of Vertebrate Paleontology 29: 1327-133.
Wild R 1993. A juvenile specimen of Eudimorphodon ranzii Zambelli (Reptilia, Pterosauria) from the upper Triassic (Norian) of Bergamo. Rivisita Museo Civico di Scienze Naturali “E. Caffi” Bergamo 16: 95–120.

https://pterosaurheresies.wordpress.com/2011/09/09/the-origin-of-the-pterosaur-sternal-complex/

https://www.researchgate.net/publication/328388746_The_triple_origin_of_whales

https://evolution.berkeley.edu/evolibrary/article/evograms_02

https://evolution.berkeley.edu/evolibrary/article/evograms_03

https://evolution.berkeley.edu/evolibrary/article/evograms_04

https://evolution.berkeley.edu/evolibrary/article/evograms_05

https://evolution.berkeley.edu/evolibrary/article/evograms_06

https://evolution.berkeley.edu/evolibrary/article/evograms_07

https://ucmp.berkeley.edu/vertebrates/flight/pter.html

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

SVP abstracts – the Skye pterosaur

Martin-Silverstone, Unwin and Barrett  2019 bring us
news of a new Middle Jurrasic Scottish pterosaur: the Skye pterosaur.

From the abstract
“The Middle Jurassic was a critical time in pterosaur evolution – a series of major morphological innovations underpinned radiations by, successively, rhamphorhynchids, basal monofenestratans, and pterodactyloids. Frustratingly, however, this interval is also one of the most sparsely sampled parts of the pterosaur fossil record, consisting almost exclusively of isolated fragmentary remains.”

…other than all the many complete Jianchangnathus, Changchengopeterus, Pterorhynchus, Darwinopterus, and Dorygnathus specimens, that is. Why are these three pterosaur experts pretending these wonderfully preserved taxa don’t exist?

Figure 1. Skye pterosaur from traced from in situ specimens found online.

Figure 1. Skye pterosaur in ventral view traced from in situ specimen photos found online with limbs duplicated graphically. This preliminary data was enough to nest it in the LPT better than three PhDs with a set of µCT scans hampered by their much smaller unresolved pterosaur cladogram.

Martin-Silverstone et al. continue:
“Here we report on the most complete individual found to date, a three-dimensionally
 preserved, partial pterosaur skeleton recovered in 2006 from the Bathonian-aged Kilmaluag Formation, near Elgol, Isle of Skye, Scotland. Micro-CT scanning, segmentation, and 3D-reconstruction using Avizo has revealed multiple elements of the axial column, fore-, and hind limbs, many of which were fully embedded within the matrix and inaccessible via traditional preparation and imaging techniques.”

“Unique features of the coracoid distinguish the Skye pterosaur from all other species, indicating that it represents a new taxon.”
“The new specimen was included in phylogenetic analysis that was conducted using maximum parsimony in PAUP on a data matrix consisting of 61 taxa scored for 136 morphological characters. This analysis generated 544,320 MPTs.
OMG!!! What a confession!! That is a sign of a  lousy cladogram!!
“The 50% majority rule tree places the Skye taxon as a basal monofenestratan in a clade with Darwinopterus, Wukongopterus, and, for the first time, Allkaruen, which was previously identified as non-monofenestratan.
The LPT confirms the nesting of the Skye pterosaur with Darwinopterus, but closer to Jianchangnathus and Pterorhynchus (Fig. 2). In the LPT, Alkaruen nested basal to the ctenochasmatid, Pterodaustro. Details on that here.
Figure 3. Subset of the LPT showing the nesting of the Skye pterosaur from available data (Fig. 1).

Figure 2. Subset of the LPT showing the nesting of the Skye pterosaur from available data (Fig. 1). This is a terminal clade with no known descendants, contra Martin-Silverstone, Unwin and Barrett.

The Skye pterosaur, one of the earliest, most complete records for Monofenestrata, provides critical new insights into pterosaur evolution.”
The large pterosaur tree (LPT, 241 taxa; subset Fig. 2) once again finds no evidence for a monophyletic Monofenestrata and the entire LPT is resolved. If the Martin-Silverstone, Unwin and Barrett team added 180 taxa they would also find no evidence for a monophyletic Monofenestrata and their resolution would increase.
“The distal end of the Skye pterosaur’s scapula is expanded and articulated with the vertebral column, a feature shared with other basal mononfenestratans. Comparisons across Pterosauria show that this type of bracing was far more widespread than previously realized and seemingly present in many clades, with the exception of basal-most (Late Triassic) forms. The development of a notarium, providing additional stability and support, is confined to derived and often large and giant species and forms only part of the complex evolutionary history of the scapulo-vertebral contact.”
They could have simply said, a notarium is present. Instead they took a paragraph to do so, omitting many other traits that could have been mentioned. When scientific data is published, the authors of that data open their work for criticism and assistance. In that way errors are corrected and omissions are included.
Googling ‘Skye pterosaur’ results in several hits
including this classified ad from a year ago seeking a paleo student to work with a set of pterosaur expert PhDs. Hope it was a fulfilling experience for that student.
“Closing in January 2019: We seek a student with experience in studying and describing fossil and/or living animal specimens, comparative vertebrate anatomy, a broad background in biological and/or geological sciences, and experience or a willingness to learn statistical and CT techniques. As the student will be working with a large team, teamwork skills and a collaborative mindset are essential.” palass.org/careers

References
Martin-Silverstone E, Unwin DM and Barrett PM  2019. A new, three-dimensionally preserved monofenestratan pterosaur form the Middle Jurassic of Scotland and the complex evolutionary history of the scapulo-vertebrael articulation. Journal of Vertebrate Paleontology abstracts.

Geographic cladogram of pterosaurs

So many pterosaurs come from so few places.
And those places are spread around the world. So, here (Fig. 1) is the large pterosaur tree (LPT, 239 taxa) with color boxes surrounding Solnhofen, Chinese, North American, South American and other geographic areas where they are found.

Figure 1. LPT with pterosaurs colorized according to geography.

Figure 1. LPT with pterosaurs colorized according to geography.

As before,
the traditional clades ‘Pterodactyloidea’ and ‘Monofenestrata‘ become polyphyletic when traditionally omitted taxa are included. Here (Fig. 1) four clades achieve the pterodactyloid-grade by convergence. Other pterosaur workers (all PhDs) omit or refuse to include most of these taxa, leading to false positives for the tree topologies they recover. Moreover, none recognize, nor cite literature for, the validated outgroup members for the Pterosauria (Fig. 1) preferring to imagine pterosaurs arising from unidentified and/or invalidated archosaurs or archosauriforms. Here we get to peak beneath the curtain.


References
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
Peters D 2000b. 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. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.

Forfexopterus: a Huanhepterus sister

Boy, it’s been a long time
since we’ve looked at a new pterosaur. Several months, perhaps… maybe longer…

Figure 1. Forfexopterus reconstructed. Note the metacarpals: 1>2>3, shared with Ardeadactylus. The rostrum tip is off the matrix.

Figure 1. Forfexopterus reconstructed. Note the metacarpals: 1>2>3, shared with Ardeadactylus. The rostrum tip is off the matrix. Note the difference between the actual fingers and the traced fingers by Jiang et al. The lack of precision in the Jiang et al. tracing, despite it being traced from a photograph, is a little disheartening.

Jiang et al. 2016
present a new disarticulated, but largely complete Early Cretaceous pterosaur, Forfexopterus jeholensis (Figs. 1–3). Jiang et al. consider their new find an ‘archaeopterodactyloid’ based on the ‘long metacarpus and reduced mt5’–but those are convergent traits in four pterodactyloid-grade clades. The large pterosaur tree (LPT) nests Forfexopterus near the base of the azhdarchid clade, which arises from the Dorygnathus clade, specifically nesting between Ardeadactylus and Huanhepterus + Mesadactylus (BYU specimen, not the anurognathid with the same name).

Figure 1. Forfexopterus original tracing, colors added.

Figure 2. Forfexopterus original tracing, colors added. See how simple colors ease the chaos of the roadkill fossil.

Unfortunately 
the Jiang et al. phylogenetic analysis suffers from taxon exclusion. They consider the Archaeopterodactyloidea to be composed of Germanodactylidae, Pterodactylus, Ardeadactylus. Gallodactylidae and Ctenochasmatidae. Those members are only monophyletic if the clade also includes Dorygnathus in the LPT, which was not the intention of the authors. It’s been awhile, but let us recall that the former clade “Pterodactyloidea” had four separate origins in the LPT, two from Dorygnathus (Ctenochasmatidae and Azhdarchidae) and the rest from Scaphognathus which was, in turn, also derived from Dorygnathus through several intervening transitional taxa.

Figure 2. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

Figure 3. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

Forfexopterus
has the slender proportions of Huanhepterus and Ardeadactylus. The rostrum was longer and lightened with several fenestra, one of which was likely a naris. Metacarpals 1–3 were longer medially, the opposite of basal pterosaurs. That trait lines up the joints in m1-3. Manual 4.2 is sub equal to m4.1, unique to this clade and atypical for pterosaurs in general.  Atypical for smaller members of this clade, but typical for larger members (like Jidapterus, but evidently not Huanhepterus (data comes from awkwardly produced original drawing)), the scapula was subequal to the coracoid and would have articulated with a notarium, which is not preserved, or is still largely buried (Fig. 2).

Shorthand suggestion (again)
There are two ways you can label a tetrapod phalanx:

  1. ph3d4 = phalanx 3, digit 4 (manus or pes? as shown in figure 2 above) or
  2. m4.3 = manual 4th digit, 3rd phalanx

Jiang et al. labeled their illustration using #1. You may find that method cumbersome and space consuming. I use and encourage others to use #2, the shorthand version.

When you check out the
Wikipedia page on Forfexopterus, the link to Archaeopterodactyloidea references three papers with Dr. Brian Andres as a co-author including his dissertation on
Sytematics of the Pterosauria. It’s great that PhD candidates tackle large projects. It’s hard work that makes them study their subject and prove their mettle. However, by definition, PhD candidates are not experts. They want to become experts by creating a dissertation, but they come to their projects naive, trusting the literature and beholding to their professors. These are all potential problems, as we talked about earlier.

In like manner, 
for my second paper (Peters 2000) I came to the project naive and trusting the literature. Judging from a vantage point, 17 years later, my observations were not those of an expert. Even so, I hit the mark with regard to pterosaur origins despite the many errors in that paper that have been corrected here and at ReptileEvolution.com. The nesting of pterosaurs apart from archosaurs and close to Macronemus, Tanystropheus, Langobardisaurus, Cosesaurus, Sharovipteryx and Longisquama has been validated and cemented by the large reptile tree (LRT). No other candidate taxa have ever been shown to be closer (= produce a gradual accumulation of derived traits). Attempts at correcting the observational errors in academic publications have been rejected by the referees who don’t want any more evidence published that pterosaurs are not dinosaur kin — or that tiny Solnhofen pteros are not babies.

Unfortunately
the Andres dissertation fails to produce a cladogram in which a gradual accumulation of traits can be traced in all derived taxa. For instance, anurognathids are basal to pterodactyloids in the Andres cladogram and the clade Archaepterodactyloidea was recovered. The Andres dissertation shortcoming can be attributed to taxon exclusion. By contrast, the LPT minimizes taxon exclusion by including many specimens ignored by Andres and other prior workers including multiple species within several genera and all those sparrow- and hummingbird-sized Solnhofen specimens. I know pterosaur workers are loathe to admit it, or recognize it, but those extra specimens are key to understanding pterosaur interrelations.

If you don’t look, you’ll never see.
If you don’t ask, you’ll never find out. Fellow pterosaur workers, don’t keep your blinders on. Expand your taxon lists to include a wider gamut of specimens.

This is Science.
When workers publish and referee allow manuscripts to be published they are judging the work fit for print. At that point they have stated their case. If the work stands up to rigorous scrutiny, then it will be cherished. If the work has flaws, then it’s up to fellow workers to expose those flaws for the good of Science.

References
Andres BBB 2010. Systematics of the Pterosauria. Dissertation. Yale University. p. 366.
Jiang S, Cheng X, Ma Y and Wang X 2016. A new archaeopterodactyloid pterosaur from the Jiufotang Formation of western Liaoning, China, with a comparison of sterna in Pterodactylomorpha. Journal of Vertebrate Palaeontology: e1212058.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.

wiki/Forfexopterus
wiki/Archaeopterodactyloidea

Dr. David Unwin on pterosaur reproduction – YouTube

Dr. David Unwin’ talk on pterosaur reproduction 
was recorded at the XIV Annual Meeting of the European Association of Vertebrate Palaeontologists, Teylers Museum, Haarlem, Netherlands and are online as a YouTube video.
Dr. Unwin is an excellent and engaging speaker.
However, some of the issues Dr. Unwin raises have been solved at www.ReptileEvolution.com
The virtual lack of calcite in pterosaur eggs were compared to lepidosaurs by Dr. Unwin, because pterosaurs ARE lepidosaurs.  See: www.ReptileEvolution.com/reptile-tree.htm
Lepidosaurs carry their eggs internally much longer than archosaurs, some to the point of live birth or hatching within hours of egg laying. Given this, pterosaurs did not have to bury their eggs where hatchlings would risk damaging their fragile membranes while digging out. Rather mothers carried them until hatching. The Mrs. T external egg was prematurely expelled at death, thus the embryo was poorly ossified and small.
Dr. Unwin ignores the fact that hatchlings and juveniles had adult proportions as demonstrated by growth series in Zhejiangopterus, Pterodaustro and all others, like the JZMP embryo (with adult ornithocheirid proportions) and the IVPP embryo (with adult anurognathid proportions).
Dr. Unwin also holds to the disproved assumption that all Solnhofen sparrow- to hummingbird-sized pterosaurs were juveniles or hatchlings distinct from any adult in the strata. So they can’t be juveniles (see above). Rather these have been demonstrated to be phylogenetically miniaturized adults and transitional taxa linking larger long-tailed dorygnathid and scaphognathid ancestors to larger short-tailed pterodactyloid-grade descendants, as shown at: www.ReptileEvolution.com/MPUM6009-3.htm
Thus the BMNH 42736 specimen and Ningchengopterus are adults, not hatchlings. And the small Rhamphorhynchus specimens are also small adults.

SVP 11 Pterosaur pelvic morphology

Frigot 2015 
provides general information about pterosaur pelves using principal component analysis, similar to that of Bennett 1995, 1996. I hope it works out better for Ms. Frigot.

From the abstract
“Pterosaurs have modified the basic triradiate amniote pelvis, extending the ilium into elongate processes both anterior and posterior to the acetabulum. While pterosaurs are now generally accepted to move quadrupedally on the ground*, many hypotheses exist regarding the diversity of gaits and terrains exploited across Pterosauria and how this may be correlated with the shifts in body plan found at the base of the monofenestratans and of the pterodactyloids. Early attempts to bring comparative anatomy to bear upon the topic have been largely descriptive of pelvic shape across the clade. I attempt to rectify this by providing a geometric morphometric analysis of a phylogenetically diverse sample of pterosaur pelves. Using landmark-based methods, shape was captured at the bone margins and acetabulum, with a view to capturing surfaces available for muscle attachment. These landmarks were analyzed using principal components analysis (PCA). Principal components 1 and 2 distinguish well between genera, reducing possible concerns over the role of taphonomy and ontogeny in determining shape**. It is not apparent whether the lack of a phylogenetic trend across shape space is due to small sample size or a high degree of evolutionary plasticity, highlighting the need for a greater sample size. However, with this support for a biological signal in the data, subsequent steps can be made that focus on biomechanical and locomotor analyses using detailed anatomical observations. We can then try to identify how pelvic disparity might have led to a diversity of locomotor styles in this most unique taxon.”***

*That’s traditional thinking. Many pterosaur tracks indicate bipedal locomotion.
**Ontogeny does not change pelvis shape because pterosaurs grew isometrically.
***So, sorry… no taxa or conclusions here.

References
Frigot RA 2015. The pterosaurian pelvis. An anatomical view of morphological disparity and implications for for locomotor evolution.

Trees of Life: Birds and Pterosaurs

Yale’s Richard Prum recently announced that the Tree of Life of Birds is almost complete. A genomic analysis of 198 species of birds was published in the Oct. 7 edition of the journal Nature. Prum reported, ““In the next five or 10 years, we will have finished the tree of life for birds.” I presume that means fossil taxa will also be included and scored by morphological traits because genes (genomic traits) are not available.

It is not the first time…
Trees of Life for Birds were announced earlier here, here, here and here.

Having been through a similar study, I support all such efforts. AND I will never attempt to add any but a few sample birds to the large reptile tree. Others have better access to specimens and they have a big head start on the process.

Unfortunately,
some workers have ignored the pterosaur tree of life. Recently Mark Witton ignored isometric growth patterns in pterosaurs to agree with Bennett (2013) that the genus Pterodactylus includes tiny short-snouted forms, mid-sized long-snouted forms (including the holotype, of course) and large small-heron-like forms. Witton reports, “Speaking of adulthood, it was also only recently that we’ve obtained a true sense of how large Pterodactylus may have grown. We typically imagine this animal as small bodied – maybe with a 50 cm wingspan – but a newly described skull and lower jaw makes the first unambiguous case for Pterodactylus reaching at least 1 m across the wings (Bennett 2013).”

We looked at Bennett’s paper earlier in a three part series that ended here. The taxon Witton refers to is actually just a wee bit larger than the holotype and is known from a skull, so wingspread can only be guessed. The tiny short-snouted forms are actually derived from the short-snouted scaphognathids as shown here.

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

Figure 1. Click to enlarge. The Pterodactylus lineage and mislabeled specimens formerly attributed to this “wastebasket” genus. Others have split the largest specimens of Pterodactylus from the others without employing a phylogenetic analysis.

You might recall
that one of the largest complete Pterodactylus specimens (Fig. 1) recovered by the large pterosaur tree was mistakenly removed from this genus and lumped with Ardeadactylus, a basal pre-azhdarchid, all without phylogenetic analysis.

Agreeing with Bennett,
Witton deletes some taxa that actually belong to this genus, while accepting others that do not belong, all based on eyeballing specimens without a phylogenetic analysis that includes a large gamut of specimens (that does not delete the tiny forms). Eyeballing taxa is not the way to handle lumping and splitting. Phylogenetic analysis is. We looked at the Pterodactylus wastebasket problem here.

References
Bennett  SC 2012 [2013]. New information on body size and cranial display structures of Pterodactylus antiquus, with a revision of the genus. Paläontologische Zeitschrift (advance online publication) doi: 10.1007/s12542-012-0159-8
http://link.springer.com/article/10.1007/s12542-012-0159-8

News on the Origin of Pterosaurs on YouTube

I just uploaded a pterosaur origins video on YouTube. Click here to view it.

Click to view this "Origin of Pterosaurs" video on YouTube.

Click to view this “Origin of Pterosaurs” video on YouTube. 17 minutes long. 

Back to Cuspicephalus: Germanodactylid? or Wukongopterid?

Earlier we looked at the gracile skull of Cuspicephalus which nested with Germanodactylus B St 1892 IV 1 in the large pterosaur tree.

Today we revisit this taxon after the publication of Witton et al. 2015, which attempted to related Cuspicephalus to Darwinopterus and the wukongopterids.

Cuspicephalus scarfi

Figure 1. Cuspicephalus scarfi. Click to enlarge. Note the round exoccipital process at the back of the skull. Germanodcatylids have these. Wukongopterids do not. Witton thinks that bone is an artifact.

I have rarely seen a paper with such a bogus foundation…

  1. Witton et al. support the ‘modular’ evolution of pterosaurs at the base of the Pterodactyloidea. Earlier we learned that with the simple addition of taxa (which other workers continue to avoid) there are four origins for pterodactyloid-grade pterosaurs, all following phylogenetic miniaturization, a process that happens often in reptile evolution. We also learned that there is no such thing as ‘modular’ evolution with half the body evolving and waiting for the other half to catch up. In the case of wukongopterids, the other half never developed pterodactyloid-grade traits. Wukongopterids were a terminal taxon. The non-modular evolution of long tails to short tails happened several other times at several other nodes in the pterosaur cladogram (including in the anurognathids).
  2. With several distinct genera and specimens now nesting close to Darwinopterus robustus within the Wukongopteridae, no attempt was made to figure out which of these specimens were more basal and which were more derived — as shown in the large pterosaur tree.
  3. Witton et al. support a monophyletic “Monosfenestrata” which, to them, includes pterodactyloids + wukongopterids, a tree topology that is not supported by any other published studies. In the large pterosaur tree, wukongopterids, like anurognathids, convergently developed some pterodactyloid-grade traits and not others, then left no descendants.
  4. Witton et al. did not produce their own skull tracings, but rely on cartoonish and inaccurate versions of prior work by others (apparently often by Bennett 1996). Few to no skull sutures are shown and certain inaccuracies are present.
  5. Witton et al. are not critical of the cladistic work of others (Andres et al., 2014; (Lü et al., 2010; Tischlinger and Frey, 2014), nor do they offer support for the matrix they preferred (Unwin 2003). Seems less scientific than one would like to see here. Or did they not want to do the work? Or make enemies?
Figure 2. Cuspicephalus compared to Darwingopterus and to Germanodactylus, all to scale.

Figure 2. Cuspicephalus compared to Darwingopterus and to Germanodactylus, all to scale. Click to enlarge. The large reptile tree nests Cuspicephalus with Germanodactylus. Witton et al. report a closer relationship to Darwinopterus. The presence of large exoccipital ‘ears’, an extended cranium, a pointed rostrum, a pointed ventral orbt, an alignment of the rostral crest and antorbital fenestra anterior margin all argue for the present hypothesis. The longer antoribital fenestra developed by convergence in Darwinopterus and Cuspicephalus.

Granted,
wukongopterid skulls are indeed very similar to those of germanodactylids (Fig. 2). Both clades also offer a wide variety of shapes and sizes.

With regard to a key trait
in Cuspicephalus scarfi (MJML K1918) from Witton et al. 2015: The exoccipital processes are unexpanded: they look relatively large on MJML K1918, but this is largely an artefact of distortion around the occipital region, and they are not as prominent as those of Germanodactylus or dsungaripterids.

Actually
in Cuspicephalus the exoccipitals are just as big, if not bigger relative to skull height (Fig. 2).

In the large pterosaur tree
Cuspicephalaus nests with B St 1892 IV 1, n61 in the Wellnhofer (1970) catalog, which nests with two headless taxa, Wenupteryx (MOZ 3625) and the so-called “Crato azhdarchide (SMNK PAL 3830)”

From Witton et al. “Our assessment suggests that wukongopterid skulls can be distinguished from other Jurassic monofenestratans by not only lacking the well-documented cranial  synapomorphies of pterodactyloid clades, but also through a unique combination of characters (Darwinopterus, Gemanodactylus and Cuspicephalus = D, G and C):

  1. Striated bony crest lower than the underlying prenarial rostrum, with sloping anterior margin – actually lower in G.
  2. Anterior crest terminates in the posterior region of the prenarial rostrum, closer to the anterior border of the nasoantorbital fenestra than the jaw tip – note the crest starts more anteriorly in D
  3. Reclined, but not sub-horizontal, occipital regions leans more in G.
  4. Piriform (pear-shaped) orbitbut in G and C the orbit is sharply angled ventrally
  5. Convex anterodorsal orbital marginmore convex in G + C.
  6. Short nasal processonly in D.
  7. Unexpanded exoccipital processesonly in D.
  8. Concave dorsal skull surfacenot on G, D or C.
  9. Straight ventral skull surfacepresent on G, D and C.
  10. Nasoantorbital fenestra over 50% of jaw length – on D and C
  11. Small, equally sized alveoli – only on C, larger teeth on D and G.
  12. First alveolus pair located on anterior face of jaw, with mandible over-bitten by first premaxillary tooth pair – present on G, D and C
  13. Regular tooth spacing – only on D
  14. Interalveolar spacing generally greater than tooth length – only on D
  15. Dentition extends under anterior half of the nasoantorbital region – only on G and C
  16. Relatively slender, sharply pointed conical teeth – only on C.

Chronology
Cuspicephalus is Kimmeridgian (Late Jurassic) in age. So is Germanodactylus (Kimmeridigian/Tithonian). Darwinopterus is late Middle Jurassic (Bathonian/Oxfordian) in age. No wukongopterids are found in Late Jurassic deposits. So far…

I can see why there is confusion here. 
The skulls are very similar in overall morphology. But the weight of evidence appears to lend weight to a Germanodactylus relationship for Cuspicephalus. If Witton et al. had made more precise tracings and reconstructions, if they had used a valid tree topology that included tiny pterosaurs, if they had not discounted the presence of exoccipital processes on Cuspicephalus, then I think they would have come up with a nesting that echoed that of the large pterosaur tree.

An outlandish suggestion based on a cladogram
We have a large germanodactylid skull without a body (Cuspicephalus) and we have a large germanodactylid post-crania without a skull (the Crato Azhdarchide). Although they are separated somewhat in time, they are sister taxa. Wonder how well the real skull and real post-crania would match up with these two…

Diopecephalus = P. longicollum = Ardeadactylus. Normannognathus is in the box in the lower left.

Figure 3. Witton et al. also attempted to resolve the relationships of Normannognathus without success. Here it is in the box at lower left. Phylogenetic analysis nests it with Diopecephalus = P. longicollum = Ardeadactylus.

Normannognathus
Witton et al. also considered the problem of the placement of Normannognathus (Fig. 3). Earlier we looked at the phylogenetic relationships of Normannognathus (Buffetaut et al. 1998;  MGC L 59’583) known from a toothy, curved rostrum and crest. While Witton et al. considered the problem too difficult to solve, several years ago Normannognathus was matched to the big Pterodactylus longicollum (SMNS-56603, No. 58 of Wellnhofer 1970), which was not considered by Witton et al.

References
Andres B, Clark J, Xu X. 2014. The earliest pterodactyloid and the origin of the group. Current Biology 24: 1011-1016.
Bennett SC 1996. Year-classes of pterosaurs from the Solnhofen limestones of Germany: taxonomic and systematic implications. Journal of Vertebrate Paleontology 16:432–444.
Lü JC, Unwin DM, Jin X, Liu Y, Ji Q. 2010. Evidence for modular evolution in a long-tailed pterosaur with a pterodactyloid skull. Proceedings of the Royal Society B 277: 383-389.
Tischlinger H and Frey E 2014. Ein neuer Pterosaurier mit Mosaikmerkmalen basaler und pterodactyoider Pterosaurier aus dem  Ober-Kimmeridgium von Painen (Oberpfalz, Deutschland) [A new pterosaur with moasic characters of basal and pterodactyloid Pterosauria from the Upper Kimmeridgian of Painten (Upper Palatinate, Germany)]. Archaeopteryx 31: 1-13.
Witton MP, O’Sullivan M and Martill DM 2015. The relationships of Cuspicephalus scarfi Martill and Etches, 2013 and Normannognathus wellnhoferi Buffetaut et al., 1998 to other monofenestratan pterosaurs.