Pterodactylus antiquus extreme closeups: Tischlinger 2020

Paleo-photographer Helmut Tischlinger 2020
brings us extreme closeups of the first pterosaur ever described, Pterodactylus antiquus (Figs 1–7), in white and UV light. Here both photos of the same area are layered precisely to demonstrate the different details each type of light brings out.

The text is German.
The abstract and photo captions are duplicated in English.

Pterodactylus antiquus (Collini 1784, Cuvier 1801, 1809, Sömmerring 1812, BSP Nr. AS I 739No. 4 of Wellnhofer 1970; Late Jurassic) was the first pterosaur to be described and named.

Figure 1. Reconstruction of Pterodactylus antiquus made prior to Tischlinger 2020.

Figure 1. Reconstruction of Pterodactylus antiquus made prior to Tischlinger 2020.

From the Abstract:
“On the occasion of the reopening of the Jura Museum Eichstätt on January 9, 2020, the Bavarian State Collection for Paleontology and Geology, Munich, provided the Jura Museum with one of its most valuable fossil treasures as a temporary loan. The “Collini specimen”, first described in 1784, is the first scientifically examined and published fossil of a pterosaur and has been at the center of interest of many natural scientists since it became known… An examination of the texture of the surface of the limestone slab and the dendrites on it suggests that it does not come from Eichstätt, as has been claimed by Collini, but most likely from the Zandt-Breitenhill quarry area about 30 km east of Eichstätt. For the first time, a detailed investigation and pictorial documentation were carried out under ultraviolet light, which on the one hand document the excellent preservation of the fossil, and on the other hand show that there has obviously been no damage or manipulation to this icon of pterosaurology during the past almost 240 years.”

Figure 2. Pterodactylus wing ungual.

Figure 2. Pterodactylus wing ungual in white light and UV. Not sure why the two images are not identical, but elsewhere teeth appear and disappear depending on the type of light used.

The wing tip ungual 
appears to be present in visible light, but changes to a blob under UV (Fig. 2). Other pterosaurs likewise retain an often overlooked wingtip ungual.

In the same image
the skin surrounding an oval secondary naris within the anterior antorbital fenestra appears. Otherwise very little soft tissues is preserved.

The ‘secondary naris’ may be a new concept for some,
so it is explained below. This is not the same concept as the hypothetical ‘confluent naris + antorbital fenestra’ you may have heard about. Remember, ‘pterodactloid’-grade pterosaurs arose 4x by convergence. So each had their own evolutionary path.

Figure 3. Pterodactylus rostrum from Tischlinger 2020, colors added here. Note the original naris appears as a vestige above the maxilla tip, as in the Triassic pterosaur, Bergamodactylus and the Pterodactylus ancestor, Scaphoganthus.

Figure 3. Pterodactylus rostrum from Tischlinger 2020, colors added here. Note the original naris appears as a vestige above the maxilla tip, as in the Triassic pterosaur, Bergamodactylus and the Pterodactylus ancestor, Scaphoganthus. The shape of that narial opening is different in UV and white light.

The elements of the paper-thin rostrum
are colorized here (Fig. 3). There are subtle differences between the white light and UV images. The pink color represents a portion of the nasal that extends to the anterior maxilla and naris as in other pterosaurs and tetrapods. Did I just say naris? Yes.

Note the original naris here appears as a vestige
in its usual place above the maxilla tip, as in the Triassic pterosaur, Bergamodactylus and the late-surviving Pterodactylus ancestor, Scaphoganthus. The transition to this vestigial naris is documented in the rarely published n9 (SoS 4593), n31 (SoS 4006) and SMNS 81775 tiny transitional taxa (Fig. 4). After testing, all these turn out to be miniaturized adults traditionally mistakenly considered to be juveniles, only by those pterosaur workers who have excluded these taxa from phylogenetic analysis.

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 4. 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).

That’s why it is so important
to include all pterosaurs specimens as taxa in analysis. Otherwise you will miss the phylogenetic miniaturization that occurs at the genesis of major clades, the phylogenetic variation within a genus, and the evolution of new traits that have been overlooked by all other pterosaur workers.

Figure 2. Pterodactylus metacarpus including 5 digits.

Figure 5. Pterodactylus metacarpus including 5 digits. Colors added here.

The elements of the right metacarpus
are better understood and communicated when colorized (Fig. 4). Not sure where the counter plate is, but it may include some of the elements missing here, like the distal mc1. The left manus digit 5 is on that counter plate, judging from the broken bone left behind on the plate.

Figure 6. Pterodactylus antiquus pes in situ and restored to in vivo appearance.

Figure 6. Pterodactylus antiquus pes in situ and restored to in vivo appearance.

The pes is well preserved
Adding DGS colors to the elements helps one shift them back to their invivo positions. The addition of PILs (parallel interphalangeal lines, Peters 2000) complete the restoration. This is a plantigrade pes, judging by the continuous PILs that other workers continue to ignore.

Figure 6. Pterodactylus in situ under white light and UV from Tischlinger 2020. Colors added here.

Figure 7. Pterodactylus in situ under white light and UV from Tischlinger 2020. Colors added here.

Sometimes PhDs overlook certain details.
And that’s okay. Others will always come along afterward to build on their earlier observations. Tischlinger 2020 provides that excellent opportunity.


References
Collini CA 1784. Sur quelques Zoolithes du Cabinet d’Histoire naturelle de S. A. S. E. Palatine & de Bavière, à Mannheim. Acta Theodoro-Palatinae Mannheim 5 Pars Physica, 58–103.
Cuvier G 1801. [Reptile volant]. In: Extrait d’un ouvrage sur les espèces de quadrupèdes dont on a trouvé les ossemens dans l’intérieur de la terre. Journal de Physique, de Chimie et d’Histoire Naturelle 52: 253–267.
Cuvier G 1809. Mémoire sur le squelette fossile d’un reptile volant des environs d’Aichstedt, que quelques naturalistes ont pris pour un oiseau, et dont nous formons un genre de Sauriens, sous le nom de Petro-Dactyle. Annales du Muséum national d’Histoire Naturelle, Paris 13: 424–437.
Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos, 7: 11-41
Tischlinger H 2020. Der „Collini-Pterodactylus“ – eine Ikone der Flugsaurier-Forschung Archaeopteryx 36: 16–31; Eichstätt 2020.
von Soemmering ST 1812. Über einen Ornithocephalus. Denkschriften der Akademie der Wissenschaften München, Mathematischen-physikalischen Classe 3: 89-158.
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Pterodactylus

 

 

 

 

The ‘feathery’ anurognathid repaired with higher resolution

No one likes to trace and reconstruct
small, crushed anurognathid pterosaurs. That’s where Digital Graphic Segregation (DGS; Fig. 1) comes into play. Come to think of it, it’s rare that any pterosaur worker attempts to trace an anurognathid in precise detail before going straight to freehand (Fig. 1 upper left by Wang, Zhou, Zhang and Xu 2002; Bennett 2007).

Figure 1.  Comparing data gathering results using first-hand observation with the DGS method on the skull of Jeholopterus.. The digital outlines were then transferred into the reconstruction.

Back in 2006 I made a first attempt
at reconstructing this specimen (CAGS Z070, originally CAGS IG 02-81, Figs. 2–6), back when it was considered Jeholopterus sp. (Lü et al., 2006). That was before any other disc-head anurognathids were known and early in my studies using low-resolution images.

Those mistakes are corrected here
(Figs. 2, 3) with higher resolution images provided by Yang et al. 2018 and a fair amount of practice during the intervening years from several other disc-head pterosaurs, like SMNS 81928 (Bennett 2007) Discodactylus and Vesperopterylus.

Figure 1. The skull of the fuzzy anurognathid CAGS Z020 under DGS.

Figure 2. The skull of the fuzzy anurognathid CAGS Z070 under DGS. This is a ventral exposure. Elements match those of other anurognathids. Colors enable rapid and easy identification of every bone. The mandible is blue, shown together with the palate elements. Below in red are the quadrates. Note how low and wide the skull is.

DGS comes in handy
to segregate and reconstruct the bones of the CAGS Z070 specimen exposed in ventral view. (Fig. 2). All the elements are similar to those in other disc-head anurognathids.

Figure 2. CAGS Z020 anurognathid reconstructed in lateral view. As in other disc-head anurognathids the frog-like eyeballs likely rose above the flat skull.

Figure 3. CAGS Z020 anurognathid reconstructed in lateral view. As in other disc-head anurognathids the frog-like eyeballs likely rose above the flat skull.

Note: There are no giant eyeballs in the front half of the skull here,
nor in any anurognathid pterosaurs (Fig. 4). When Bennett 2007 mistook a maxilla for a giant scleral ring, that became gospel to a generation of lazy anurognathid workers and artists. No giant eye rings have ever been found since in any pterosaur. No matching giant eye ring was ever found on the original Bennett 2007 specimen. Better still, try to trace the bones yourself — because in science anyone can repeat a valid observation.

That being said, this is a difficult skull to trace.
Fortunately evolution works in micro steps and we’ve had several other disc-head anurognathids to look at for the Bauplan (= blueprint). You may need to practice on a few before tackling the CAGS specimen preserved in palatal / ventral view.

FIgure 3. A selection of anurognathid skulls. All follow the pattern of a small eye ring in the posterior half of the skull, except Bennett's 2007 freehand reconstruction.

FIgure 4. A selection of anurognathid skulls from 2013. All follow the pattern of a small eye ring in the posterior half of the skull, except Bennett’s 2007 freehand reconstruction.

You might remember, Yang et al. 2018
used this CAGS specimen to say pterosaurs had something like feathers all over their body. New Scientist  and The Scientist quotes several pterosaur experts in their handling of this story. All of them fell prey to ‘Pulling a Larry Martin‘ by focusing on one trait while ignoring a long list of missing taxa and all their traits. None of the following pterosaur experts traced the materials nor performed the necessary phylogenetic analyses.

  1. “I think it’s now case closed, pterosaurs had feathers.” —Steve Brusatte
  2. “Our interpretation is that these bristle-type structures are the same as the feathers on birds and dinosaurs,” —Mike Benton
  3. “This is a very important discovery, because it shows that integumentary [skin] filaments evolved in both dinosaurs and pterosaurs. That’s not surprising because they are sister groups, but it is good to know.” —Kevin Padian
  4. ”The thing that is cool is that it bolsters the idea that pterosaurs and dinosaurs are sister taxa, if they are correct in interpreting these structures as a type of feather,” —David Martill

Surprisingly taking a more critical point-of-view is Chris Bennett, “The authors’ characterization of the integumentary structures as ‘feather-like’ is inappropriate and unfortunate. It seems to me to be premature to use filamentous integumentary structures to support a close phylogenetic relationship between pterosaurs and dinosaurs.”

The CAGS specimen

Figure 5. The CAGS specimen attributed to Dendrorhyncoides and then to Jeholopterus, but is distinct from both.

In the large reptile tree
(LRT, 1707+ taxa) pterosaurs are fenestrasaur, tritosaur lepidosaurs. In other words, pterosaurs are closer to lizards than to dinosaurs. Overlooked by Benton and the others, several pterosaur outgroups (e.g. Cosesaurus, etc.) also have furry, fuzzy, feathery coverings. Perhaps thinking of the status quo, scientists who collect a paycheck have preferred not to test this twenty-year-old hypothesis of interrelationships (Peters 2000). Sometimes it takes an outsider with gobs of retirement time to expose the fallacies of traditional textbooks (= secondary profit generators).

Figure 2. Interpretation of bony and soft tissue elements in the CAGS specimen. Click to see rollover image.

Figure 6. Interpretation of bony and soft tissue elements in the CAGS specimen. Click to see rollover image.

A note on the ventral view of the CAGS skull:
The reduction of the maxillary palate bones to slender Y-shaped structures (green in Fig. 2) has not been noticed by other workers content with freehand illustrations. Earlier in 2013 the hypothesis was proposed that these slender Y-shaped bones acted like sensors in flight while feeding on flying insects. Once the fly touched the sensor, the open jaws would snap shut. Flies and mosquitos were radiating during the Triassic alongside these aerial insect eaters.

Phylogeny
Despite these several skull score changes, no shift in topology toward the other flat-head anurognathids was recovered.


References
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Lü J-C, Ji S, Yuan C-X and Ji Q 2006. Pterosaurs from China. Geological Publishing House, Beijing, 147 pp.
Wang X, Zhou Z, Zhang F and Xu X 2002. A nearly completely articulated rhamphorhynchoid pterosaur with exceptionally well-preserved wing membranes and “hairs” from Inner Mongolia, northeast China. Chinese Science Bulletin 47(3): 226-230.
Yang et al. (8 co-authors including Benton MJ) 2018. Pterosaur integumentary structures with complefeather-like branching. Nature ecology & evolution

wiki/Jeholopterus

The sculpture shown on the Jeholopterus wiki page is based on my model, but they changed the skull to reflect the Bennett 2007 type skull… which is a mistake.

https://pterosaurheresies.wordpress.com/2018/12/18/pterosaur-pycnofibres-revisited-yang-et-al-2018/

https://pterosaurheresies.wordpress.com/2014/02/13/anurognathid-eyes-the-evidence-for-a-small-sclerotic-ring/

https://pterosaurheresies.wordpress.com/2013/06/21/anurognathids-and-their-snare-drum-palates/

https://www.newscientist.com/article/2188405-stunning-fossils-show-pterosaurs-had-primitive-feathers-like-dinosaurs/

https://www.the-scientist.com/news-opinion/pterosaurs-sported-feathers–claim-scientists-65220

 

New Quetzalcoatlus northropi skeletal model from Triebold Paleontology

Short one today
… focusing on a tall pterosaur skeleton model.

Figure 1. A Quetzalcoatlus northropi model from Triebold Paleontology scaled up from a Q. sp. sculpture I made and sold to Triebold.

Figure 1. A Quetzalcoatlus northropi model from Triebold Paleontology scaled up from a Q. sp. sculpture I made and sold to Triebold. Maybe it is posed trying to cool itself off, by those wing fingers can fold up against the arms for membrane protection.

First time I’ve seen this. 
Although I heard rumors that Mike Triebold (Triebold Paleontology) had scaled up the Q. sp. model I sold him a few years ago (Fig. 2) to create a 3x taller Quetzalcoatlus northropi model (Fig. 1). Giants are fascinating.

Quetzalcoatlus neck poses. Dipping, watching and displaying.

Figure 2. Quetzalcoatlus neck poses. Dipping, watching and displaying. Yes, that was my living room.

The shorter original was held together by wire
so it could be manipulated into one pose after another, or stuffed away into a small box.

As a reminder,
the brevity of the wings (vestigial distal phalanges) and the top-heavy proportions otherwise mark this as a flightless pterosaur.

Quetzalcoatlus running like a lizard prior to takeoff.

Figure 3. Quetzalcoatlus running like a lizard unable to take off due to vestigial distal wing elements and proportions that sent the center of balance anterior to the wing chord.

Even so, those wings were powerful thrusters
for speedy getaways on land (Fig. 3). I realize this is heresy, but facts are facts. Clipped wings in birds and pterosaurs means they cannot fly. And only flightless birds and pterosaurs are able to achieve such giant sizes (Fig. 4).

Figure 1. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale.

Figure 1. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale.

The Berlin Naturkundemuseum Pterodactylus reconstructed

The MBR 3655 specimen of Pterodactylus in situ
looks like roadkill. Here (Fig. 1) a second sort of DGS (Digital Graphic Segregation) is used to reassemble the jumble. This sort does not rely on someone tracing each bone with transparent color. This goes faster and further minimizes freehand bias and error. More of the pertinent pixels in the original are used in the reconstruction.

Figure 1. The MBR3655 specimen of Pterodactylus reconstructed using DGS methods from the in situ photo.

Figure 1. The MBR3655 specimen of Pterodactylus reconstructed using DGS methods from the in situ photo. The foot proportion pattern is unique and the sternum rccalls that of Scaphoganthus.

When added
to the Large Pterosaur Tree (LPT, 289 taxa) this taxon nests at the base of one of the Pterodactylus clades that include the Vienna specimen (NHMW 1975/1756) and the n21 specimen (BSP1937 I 18). Still have not found two identical (conspecific) taxa from the Solnhofen Formation except the only known juvenile Rhamphorhynchus, a mid-sized juvenile of one of the largest species discussed earlier here.


References
Broili F 1938. Beobachtungen an Pterodactylus. Sitz-Bayerischen Akademie der Wissenschaten, zu München, Mathematischen-naturalischenAbteilung: 139–154.
Wellnhofer P 1970. Die Pterodactyloidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Abhandlungen der Bayerischen Akademie der Wissenschaften, N.F., Munich 141: 1-133.

wiki/Pterodactylus

New basal tapejarid with broken wings needs specimen number, citation

Updated April 1, 2020
The specimen number is SMA 0154 / 02. Kind readers reported the location of this specimen: Sauriermuseum, Aathal, Switzerland. I can now reveal the phylogenetic nesting of this specimen is between Sinopterus and Tapejara. I know of no citation yet.

Figure 1. Complete basal tapejarid without identification. Please provide a museum number or citation if possible.

Figure 1. Complete basal tapejarid without identification. Please provide a museum number or citation if possible.

This image above (Fig. 1) appears on the website,
Tapejaraluv.weebly.com” under the headline “The Tapejara,” created by Jordyn Rosen and Teya Good. There are no ‘contact us‘ or ‘comments‘ links on their website and all attempts at finding them elsewhere on the ‘net don’t seem to be leading to any Tapejara fans. 

I will forego posting any more information on this specimen
pending the acquisition of a citation or museum number on the chance that it is currently under study and awaiting publication. Even so, it has been added to the large pterosaur tree (LPT) as the 243rd taxon, but not yet posted online.

Lepidosaur bipedality and pelvis morphology: Grinham and Norman 2019

Grinham and Norman 2019
brings us a new look at 34 lepidosaur pelves with an emphasis on trends associated with bipedal locomotion. The authors illustrated 11 pelves (Fig. 1, white and yellow areas).
Figure 1. On the left, lepidosaur pelves from Grinham and Norman 2019, reordered phylogenetically here. On the right several tritosaur pelves and prepubes, most of which strongly demonstrate bipedal traits (elongate anterior ilium, increased sacral number). Yellow boxes indicate facultatively bipedal extant lepidosaurs.

Figure 1. On the left, lepidosaur pelves from Grinham and Norman 2019, reordered phylogenetically here. On the right several tritosaur pelves and prepubes, most of which strongly demonstrate bipedal traits (elongate anterior ilium, increased sacral number). Yellow boxes indicate facultatively bipedal extant lepidosaurs.

From the Grinham and Norman abstract:
“Facultative bipedality is regarded as an enigmatic middle ground in the evolution of obligate bipedality and is associated with high mechanical demands in extant lepidosaurs. Traits linked with this phenomenon are largely associated with the caudal end of the animal: hindlimbs and tail. The articulation of the pelvis with both of these structures suggests a morphofunctional role in the use of a facultative locomotor mode. Using a three-dimensional geometric morphometric approach, we examine the pelvic osteology and associated functional implications for 34 species of extant lepidosaur. Anatomical trends associated with the use of a bipedal locomotor mode and substrate preferences are correlated and functionally interpreted based on musculoskeletal descriptions. Changes in pelvic osteology associated with a facultatively bipedal locomotor mode are similar to those observed in species preferring arboreal substrates, indicating shared functionality between these ecologies.”
Unfortunately, Grinham and Norman omitted
tritosaur lepidosaurs from their study. In the Triassic many of them became bipeds and among these, pterosaurs achieved bipedalism supported with four, five and more sacral vertebrae between horizontally elongate ilia, convergent with dinosaurs. The addition of the prepubis virtually extended the anchorage for the puboischial muscles. After achieving flight, beach-combing pterosaurs reverted to a quadrupedal configuration with finger 3 pointing posteriorly. Giant Korean bipedal pterosaur tracks are best matched to large dsungaripterid/tapejarid clade taxa.
Unfortunately, Grinham and Norman reported,
“A recently published molecular-based time-calibrated phylogeny for Squamata was pared down to match the species in our dataset.” Their genomic cladogram bears little to no resemblance to the large reptile tree (LRT, 1635+ taxa), which tests traits, not genes. Once again, genes produce false positives. 
The authors’ principal component analysis of the pelvis failed 
to isolate bipedal lepidosaurs from the rest. Grinham and Norman reported, “The shape of the pelvis in facultatively bipedal extant lepidosaurs falls within the overall morphospace of lepidosaurs generally.” This is also visible in their illustrated pelves (Fig. 1). They also reported, However, it is generally found in a very concentrated area of that morphospace.” And Conclusions can be drawn regarding pelvic morphology and substrate use, although not with the same clarity as for locomotor mode.”
Grinham and Norman 2019 conclude,
“we have used 3D landmark-based geometric morphometrics to demonstrate that the overall morphospace for the lepidosaur pelvis is broad and wide-ranging. Within this overall morphospace, a small region is occupied by facultative bipeds. The vast majority of this smaller morphospace overlaps that occupied by species that show a preference for arboreal habitats. Pelvic morphological adaptations relevant for living in an arboreal environment are similar to those necessary to facilitate facultative bipedality.”
That’s interesting with regard to
the arboreal abilities of volant basal bipedal pterosaurs and their ancestors. Maybe next time Grinham and Norman will expand their study to include tritosaur lepidosaurs.

References
Grinham LR and Norman DB 2019. 
The pelvis as an anatomical indicator for facultative bipedality and substrate use in lepidosaurs. Biological Journal of the Linnean Society, blz190 (advance online publication) doi: https://doi.org/10.1093/biolinnean/blz190
https://academic.oup.com/biolinnean/advance-article-abstract/doi/10.1093/biolinnean/blz190/5687877Â
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Snyder RC 1954. The anatomy and function of the pelvic girdle and hind limb in lizard locomotion. American Journal of Anatomy 95:1-46.

Pterosaur prebubis

 

First pterosaur basihyal (Gladocephaloideus?, Gallodactylidae?)

Jiang, Li, Cheng and Wang 2020 bring us
the first evidence of a tiny medial hyoid bone, the basihyal (Fig.1; IVPP V 14189). Comparisons were made to “scavenger crows rather than chameleons.” Other pterosaurs have hyoids, but, until now, not a basihyal. Really, that’s all the authors needed to say. The rest of what they presented was filler, little of it accurate or valid.

Figure 1. Images from Zheng et al. 2020 scaled, rotated and layered. This is all that is known of this specimen. Micro -CL image shows hollow basihyal.

Figure 1. Images from Jiang et al. 2020 scaled, rotated and layered. This is all that is known of this specimen. Micro -CL image shows hollow basihyal.

Overlooked by the authors,
Cosesaurus (Fig. 2), Sharovipteryx, Kyrgyzsaurus and Longisquama also have hyoids  The authors considered their specimen close to Gladocephaloideus (Fig. 3), which they considered a gallodactylid. Here Gladocephaloides nests with Gegepterus, a ctenochasmatid.

Figure 2. Cosesaurus nasal crest (in yellow).

Figure 2. Cosesaurus hyoids in bright green.

Jiang et al. 2020 presented a greatly simplified cladogram
of pterosaur interrelationships… so simplified that it bears little resemblance to a more complete pterosaur cladogram. Kryptodrakon (junior synonym for Sericipterus) was misspelled Kryptondrakon.

Figure 1. Gladocephaloideus (the holotype) compared to the new specimen referred to Gladocephaloideus and its two sister taxa in the large pterosaur tree. Long necks in ctenochasmatids made several appearances by convergence.  Of particular interest, note the size of the pelvis in the JPM specimen, no larger than that of the much smaller MB.R. specimen. Lü et al considered the pelvis incomplete and it may be. Sister taxa are illustrated here from figure 2.

Figure 3. Gladocephaloideus (the holotype) compared to the new specimen referred to Gladocephaloideus and its two sister taxa in the large pterosaur tree. Long necks in ctenochasmatids made several appearances by convergence.  Of particular interest, note the size of the pelvis in the JPM specimen, no larger than that of the much smaller MB.R. specimen. Lü et al considered the pelvis incomplete and it may be. Sister taxa are illustrated here from figure 2.

According to Jiang et al.
“The hyoids of primitive non-pterodactyloids only include the preserved ceratobranchials; this rod-like element is slender and quite long relative to the skull length. The ceratobranchial/skull length ratio is similar to most extant reptiles.” OK. Good to know.


References
Jiang S-X, Li Z-H, Cheng X and Wang X-L 2020. The first pterosaur basihyal, shedding light on the evolution and function of pterosaur hyoid apparatuses. DOI 10.7717/peerj.8292

Could this azhdarchid eat this baby dinosaur?

Artist and paleontologist Mark Witton, U of Portsmouth,
published an iconic image of an azhdarchid pterosaur biting a baby sauropod prior to eating and digesting it (Fig. 1, Witton and Naish 2008). While biting a baby dinosaur in this fashion certainly was possible, could this azhdarchid swallow and digest it? Let’s see.

Figure 1. Above: original art from artist M Witton showing azhdarchid biting baby sauropod. Below: Azhdarchid organs including stomach (green) do not appear to be able accommodate such a large meal. Gastralia prevent ventral expansion.

Figure 1. Above: original art from artist M Witton (Witton and Naish 2008) showing azhdarchid biting baby sauropod. Below: Azhdarchid organs including stomach (green) do not appear to be able accommodate such a large meal. Gastralia prevent ventral expansion.

A skeletal view of the same azhdarchid
to the same scale (Fig. 1 below) shows the approximate lungs (blue), heart (red), liver (brown), stomach (green), intestines (pink), kidneys (red brown) and bladder (yellow) along with the same  baby dinosaur reduced slightly due to perspective. The wing membranes are also repaired. The tiny sternum is shown on the chest of the biting azhdarchid, another factor in giant azhdarchid flightlessness.

Based on the given parameters
the azhdarchid stomach (green) does not appear to be able to accommodate such a large meal all at once.

The analogous saddle-billed stork
(Ephippiorhynchus senegalensis, Fig. 2) eats what appears to be a similar-sized meal, but note the abdomen of the bird is relatively much larger than that of the azhdarchid and the meal is relatively smaller, much more flexible, without limbs, largely meat/muscle content and wet. Unfortunately Witton and Naish did not consider stomach size in their PlosOne paper.

Figure 3. In my opinion this saddle-bill stork wading in water appears to be the bird closest to azhdarchid morphology and, for that matter, niche.

Figure 2. In my opinion this saddle-bill stork (genus: Ephippiorhynchus) wading in water appears to be the bird closest to azhdarchid morphology and, for that matter, niche.

An alternative wading lifestyle,
(Figs. 2, 3) dismissed by Witton and Naish 2008, appears to be more appropriate, based on the stomach size and other wading stork-like traits evidenced by azhdarchids. In LiveScience.com writer Jeanna Bryner (link below) wrote, ‘Witton and Naish learned that more than 50 percent of the azhdarchid fossils had been found inland. Other skeletal features, including long hind limbs and a stiff neck, also didn’t fit with a mud-prober or skim-feeder. All the details of their anatomy, and the environment their fossils are found in, show that they made their living by walking around, reaching down to grab and pick up animals and other prey,” Naish said.

“Their tiny feet also ruled out wading in the water or probing the soft mud for food. “Some of these animals are absolutely enormous,” Witton told LiveScience. “If you go wading out into this soft mud, and you weigh a quarter of a ton, and you’ve got these dinky little feet, you’re going to just sink in.”

Quetzalcoatlus neck poses. Dipping, watching and displaying.

Figure 3. Quetzalcoatlus neck poses. Dipping, watching and displaying.

We don’t know how soft the mud was
wherever azhdarchids fed. Analogous herons and storks seem to deal with underwater mud very well with similarly-sized feet. Witton and Naish report, Some storks with relatively small feet are known to wade indicating that azhdarchids may have been capable of some wading activity, but the high masses of large azhdarchids may have limited their ability to wade on soft substrates. Moreover, other pterodactyloids with larger pedal surface areas (most notably ctenochasmatoids) were almost certainly better adapted waders than azhdarchids. In view of this evidence, we suggest that azhdarchids were not habitual, although perhaps faculatative, waders.”

Don’t you wish the authors had performed some sort of test
to show azhdarchids were not like storks? Perhaps they could have employed a tank full of water and a variety of mud-like, sand-like and pebble-like substrates with a model azhdarchid foot and hand (btw, halving the weight of the azhdarchid directed through the feet) pressed with increasing weight to gauge the amount of sink. Instead they relied on their imaginations and made suggestions based on their initial bias. Nor did they discuss the factor of the hands supporting half the weight, nor the possibility of floating on the surface, polling with the hands and feet (Fig. 4), producing manus-only tracks, which are documented.

Witton and Naish did not attempt to show the maximum size of an object an azhdarchid stomach could handle, shown above (Fig. 1). In hindsight, that would have negated their dinosaur-killer hypothesis and the reason for their paper.

Figure 1. The azhdarchid pterosaur Quetzalcoatlus floating and poling producing manus only tracks.

Figure 4. The azhdarchid pterosaur Quetzalcoatlus floating and poling producing manus only tracks.

Witton and Naish 2008 report,
“Scavenging storks and corvids manage to open carcasses quickly and bite off pieces of flesh without the aid of curved jaw tips. Therefore, it seems almost certain that azhdarchids would have been capable of feeding upon at least some elements of large carcasses, although their long skulls and necks would inhibit their ability to obtain flesh from the deepest recesses of a corpse. However, although carrion was a likely component of azhdarchid diets, they possess no anatomical features to suggest they were obligate scavengers.”

Now you can ask,
did this azhdarchid (Fig. 1) kill this baby sauropod and then pick the meat from the bone? It is important to consider this and other possibilities. If so, the best meat would have come from the base of the tail and proximal limbs, not the neck or ‘breast.’

Azhdarchids and Obama

Figure 5. Click to enlarge. Here’s the 6 foot 1 inch President of the USA alongside several azhdarchids and their predecessors. Most were knee high. The earliest examples were cuff high. The tallest was twice as tall as our President. This image replaces an earlier one in which a smaller specimen of Zhejiangopterus was used.

Phylogenetically
what azhdarchids did ever since they were the size of tiny pterodactylids (Fig. 5) in the Late Jurassic is nibbling on bottom-dwelling prey. Larger, older, later azhdarchids were able to feed further out from shore in deeper ponds than smaller taxa and younger azhdarchids.  Witton and Naish did not discuss azhdarchids in a phylogenetic context evolving from tiny wading taxa. That is unfortunate because phylogeny is the backstory that informs every taxon. Phylogeny solves so many issues. That’s why the LRT and LPT (large pterosaur tree) could be so important for paleo workers, but, so far, they prefer not to use it.

Still struggling,
Witton and Naish began their 2015 introduction with, “Azhdarchids are among the most aberrant and remarkable of pterodactyloid pterosaurs.” Not really, As figure 5 shows, azhdarchids were simply larger versions of their small to tiny Late Jurassic ancestors, some of whom were also flightless waders.


References
Witton MP and Naish D 2008. A reappraisal of azhdarchid pterosaur functional morphology and paleoecology. PLoS ONE 3(5): e2271. https://doi.org/10.1371/journal.pone.0002271
Witton MP and Naish D 2015. Azhdarchid pterosaurs: water-trawling pelican mimics or “terrestrial stalkers”?. Acta Palaeontologica Polonica, 60(3), 651-660

Seems everyone bought into this invalid hypothesis:
https://www.livescience.com/
https://www.theguardian.com

Unwin and Martill 2019 find pterosaurs ‘naked’ and ‘ugly’

Unwin and Martill 2019 report:
“With key roles in flight, thermoregulation and protection of the body, the integument was of fundamental importance to pterosaurs. Determination of the basic anatomy of this structure could provide a range of new insights into the palaeobiology of these enigmatic volant reptiles. Presently, however, there are several conflicting hypotheses regarding the construction of the integument, all founded on limited numbers of specimens, and not one of which is fully consistent with the available fossil evidence.

As mentioned yesterday, pterosaurs are not enigmatic. Unwin and Martill have chosen to avoid the scaly lepidosaurian ancestors of pterosaurs cited by Peters (2000, 2007). The integument found on pterosaurs has similar precursor integument on sister fenestrasaurs like Sharovipteryx (Fig. 1) and Longisquama, adding two taxa to their short list of pterosaurs preserving scaly integument and pycnofibers exclusive of the extradermal membranes (wings and uropatagia).

Figure 1. Note the neck skin (integument) of Sharovipteryx, a pterosaur sister.

Figure 1. Note the neck skin (integument) of Sharovipteryx, a pterosaur sister.

Unwin and Martill continue:
“We have developed a new 
model based on investigations of more than 100 specimens all of which show some form of exceptional preservation. This data set spans the entire temporal and systematic ranges of pterosaurs and a wide variety of preservational modes.”

So… “a limited number of specimens” (see above) just turned into “more than 100 specimens.” Did they just want to see if anyone was paying attention?

“The model has three principal components:
(1) A thin epidermal layer. The external surface of the integument was glabrous [= free from hair or down, smooth] with a smooth, slightly granular, or polygonal texture.

Attenuate ‘bristles’ fringed the jaws in two anurognathids and small tracts of filaments may have adorned the posterior cranium in some pterosaurs.

Perhaps these jaw and skull filaments should have been separately numbered because they are different than glabrous tissue.

(2) A layer of reticular and filamentous collagen and of variable thickness and complexity, formed much of the dermis.

Helically wound bundles of collagen fibres (aktinofibrils), were present throughout all flight patagia. Variation of aktinofibrils in terms of their dimensions, packing, orientation and stiffness permitted localized variation in the mechanical properties and behaviour of the flight patagia whichvaried from relatively stiff distally to more extensible and flexible proximally.

‘Feather-like’ structures reported in Jeholopterus appear to be partially unraveled or decayed aktinofibrils.

Again, these are all distinct tissues worthy of their own numbers.

Unwin and Martill have no idea that Jeholopterus was a vampire bat analog (Peters 2008) covered like no other pterosaur with fluffy, silent, owl-like extradermal integument. Neither Unwin nor Martill seem to make reconstructions, so neither has any idea what Jeholopterus looked like, unless they looked here (Fig. 2).

Finally, Unwin and Martill are mixing in flight membranes here. Perhaps THAT is where they get so many examples because otherwise dermal material is exceedingly rare. Integument generally means ‘covering’, so their inclusion of wing membranes is a little misleading, especially considering the ‘naked and hairless’ portion of their abstract headline.

Figure 2. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer.

Figure 2. Reconstruction of Jeholopterus. This owl-like bloodslurper was covered with super soft pycnofibers to make it a silent flyer.

Collagen fibre bundles were also present in footwebs, and in the integument of the neck and body. These structures have often been mis-identified as ‘hair’ (pycnofibres).

Again, this variety of tissues should have been numbered separately because they are different than tissue forming much of the dermis.

(3) A deep dermal layer with muscles fibres, blood vessels and nerves.

This variety of demal tissues were already described for the flight membranes, but it could also apply to normal tetrapod skin, like our own.

The pterosaur integument was profoundly different from that of birds and bats, further emphasizing the sharp disparity between these volant tetrapods.”

Why didn’t Unwin and Martill compare pterosaur integument to lepidosaur integument, specifically that of Sphenodon and Iguana (Fig. 3)? These are the two closest living relatives of pterosaurs in the large reptile tree. According to the LRT, Unwin and Martill are looking in the wrong places.

The spines of Iguana.

Figure 3. The dorsal and gular spines of Iguana are homologous with those in Sphenodon.

Not sure where Unwin and Martill
are getting data for pterosaur skin exclusive of the extradermal membranes. They don’t say. The dark wing Rhamphorhychus (Fig. 4) has the most incredible preservation of extradermal membranes, but the skull, neck and torso were prepared down to the bone.

Figure 1. The darkwing specimen of Rhamphorhynchus. Top: in situ. Middle: Soft tissues highlighted. Bottom: Neck and forelimb restored.

Figure 4. The darkwing specimen of Rhamphorhynchus. Top: in situ. Middle: Soft tissues highlighted. Bottom: Neck and forelimb restored.

So, why do Unwin and Martill think the Mesozoic got ugly?
Their abstract does not seem to answer their click-bait headline, which describes naked, hairless and featherless pterosaurs without giving one example of same based on evidence. On the contrary, employing phylogenetic bracketing, between Sharovipteryx (Fig. 1), Scaphognathus and Sordes (the hairy devil, Fig. 5), basal pterosaurs were not naked. Their fibers were not the same as hair or feathers, but unique to fenestrasaurs.

The hind limbs and soft tissues of Sordes.

Figure 5. The hind limbs and soft tissues of Sordes. Above, color-coded areas. Below the insitu fossil.

Finally…
Why were pterosaurs considered naked by Unwin and Martill when hairy Sordes (Fig. 5) was studied by Unwin, known to Martill, and not mentioned in the abstract? Very strange, indeed coming from these two.


References
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 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
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 D and Martill D 2019. When the Mesozoic got ugly – naked, hairless, (and featherless) pterosaurs. SVPCA abstracts.

New pterosaur skull from China: Nurhachius luei

Riley Black (formerly Brian Switek) wrote:
in the subhead of her Scientific American blogpost, “New pterosaur was fossilized with a ridiculous grin.”

Well… maybe,
but in situ (Fig. 1) it’s not the first or only one. And when reconstructed (Fig. 2) the grin is gone.

On the plus side,
the Aptian (Early Cretaceous) skull attributed to Nurhachius is complete, which is always wonderful, especially for such fragile skulls.

Figure 1. New Nurhachius skull in situ. Bone colors added using DGS methods. BPMC-0204

Figure 1. New Nurhachius skull in situ. Bone colors added using DGS methods. BPMC-0204. The little curved pink ridge ventral to the jugal is the displaced descending nasal process found in sister taxa. Tiny cervical ribs are present, but overlooked.

Then Black’s subhead reports, 
“A skull found in China reveals a previously unknown flying reptile.” Well, if you read the text, not really. The authors consider the new specimen congeneric with the holotype Nurhachius (Fig. 3).

FIgure 2. New Nurhachius reconstruction. Sorry,Riley, no grin. The tiny, slit-like nostril and anterior extensions of the nasal and jugal following it are shown here.

FIgure 2. New Nurhachius reconstruction. Sorry,Riley, no grin. The tiny, slit-like nostril and anterior extensions of the nasal and jugal following it are shown here.

The teeth are like those of other istiodactylids in shape and distribution,
but when you put the two Nurhachius skulls together (Fig. 3), the two are not congeneric, so far as can be determined from available data. The mandible is not as robust in the new specimen, the rostrum is not as long. There in indication of the broader rostral tip found in Istiodactylus and other istiodactylids, nor is the orbit subdivided by circumorbital processes. The referred specimen preserves post orbital and cranial bones unknown in the holotype.

Figure 3. Nurhachius ignaciobritol reconstructed to scale alongside N. luei skull. These two do not look congeneric. The authors should have shown the two together like this.

Figure 3. Nurhachius ignaciobritol reconstructed to scale alongside N. luei skull. These two do not look congeneric. The authors should have shown the two together like this.

 

The genus holotype is
Nurhachius ignaciobritoi 
(Wang, Kellner, Zhou & Campos 2005; Fig. 3) IVPP V-13288, Early Cretaceous, skull length ~30 cm, ~2.5 m wingspan). The wings are long. The free fingers and toes are tiny. The sternum portion of the sternal complex is deep.

From the abstract:
“A revised diagnosis of the genus Nurhachius is provided, being this taxon characterized by the presence of a slight dorsal deflection of the palatal anterior tip, which is homoplastic with the Anhangueria and Cimoliopterus. N. luei sp. nov. shows an unusual pattern of tooth replacement, with respect to other pterodactyloid species.”

Istiodactylus model by David Peters

Figure 4. Istiodactylus model

The phylogenetic analysis presented by Zhou et al. 2019
is not worth showing or discussing due to the inclusion of Scleromochlus (a basal bipedal croc) and the exclusion of dozens of relevant pterosaur and fenestrasaur taxa. The new Nurhachius nests in the large pterosaur tree (LPT, 240 taxa), basal to other istiodactylids, next to, but not with Nurhachius. Proximal outgroup taxa include Coloborhynchus and Criorhynchus.


References
Zhou X, Pegas RV, Leal MEC and Bonde N 2019. Nurhachius luei, a new istiodactylid pterosaur (Pterosauria, Pterodactyloidea) from the Early Cretaceous Jiufotang Formation of Chaoyang City, Liaoning Province (China) and comments on the Istiodactylidae. PeerJ 7:e7688 DOI 10.7717/peerj.7688

https://peerj.com/articles/7688/

scientificamerican.com/laelaps/new-pterosaur-was-fossilized-with-a-ridiculous-grin