Reconstructing the Cretaceous azhdarchid Keresdrakon

Kellner et al. 2019
presented a new Early or Late Cretaceous (Aptian or Campanian) toothless pterosaur preserved as several 3D bones, far from complete (Fig. 1). Keresdrakon vilsoni (CP.V 2069) was considered an “azhdarchoid pterodactyloid.” Unfortunately, neither clade is monophyletic when more taxa are added in the large pterosaur tree (LPT, 251 taxa). The authors report, “Keresdrakon vilsoni gen. et sp. nov. was recovered as a sister taxon of the tapejaridae.”

Figure 1. All that is known of Keresdrakon layered on top of a Quetzalcoatlus sp. specimen and the same ghosted and reduced to the size of Keresdrakon.

Figure 1. All that is known of Keresdrakon layered on top of a Quetzalcoatlus sp. specimen and the same ghosted and reduced to the size of Keresdrakon.

Perhaps too little of Keresdrakon is preserved
to add it to the LPT, but layering elements atop a previously completed image of the six-foot-tall Quetzalcoatlus specimen results in a pretty close match (Fig. 1). Overall Keresdrakon is about 64% the size of Q. sp. Proportionately manual 4.1 is longer than in Q. sp.

Ontogeny
The authors note, “the presence of these growth marks suggests that this bone belongsto an ontogenetically less developed individual compared to others.”

Figure 8 in Kellner et al. 2019 has a few identification errors.

  1. a is the left ilium, not the left ischium
  2. b and c are ischia, not pubes
  3. d and e are pubes, not ischia

The coracoid identified in Kellner et al. 2020
is not co-osified to the scapula and is relatively small (Fig. 1). In pterosaurs ossification or lack thereof is phylogenetic, not ontogenetic. It’s also worth noting that basal taxa in the Azhdarcho clade also have an unfused scapula and coracoid with the coracoid often much smaller than the scapula. The tiny BSPG 1911 I 31 Solnhofen specimen is one such taxon.

Co-author, Alex Kellner, along with Wann Langston
published Q. sp. in 1996, so it’s a bit surprising that Q. sp. was not immediately seen as a close match to Keresdrakon.

Sympatry
Keresdrakon were found close to the tapejarid Caiuajara in desert sandstone.


References
Kellner AWA and Langston W 1996. Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from late Cretaceous sediments of Big Bend National Park, Texas. – Journal of Vertebrate Paleontology 16: 222–231.
Kellner AWA, Weinschütz LC, Holgado B, Bantim RAM and Sayão JM 2019. A new toothless pterosaur (Pterodactyloidea) from Southern Brazil with insights into the paleoecology of a Cretaceous desert. Anais da Academia Brasileira de Ciencias 91: e20190768. DOI 10.1590/0001-3765201920190768

wiki/Quetzalcoatlus
wiki/Keresdrakon

Naked pterosaurs–or feathered? PhDs clash

Earlier Yang et al. 2019
argued that pterosaurs, like the disc-headed unnamed anurognathids, CAGS-Z070 (Fig. 1) and NJU-57003 (Fig. 2), had protofeathers and thus they were related to dinosaurs with feathers.

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

Figure 2. NJU-57003 insitu. Even though the photo is fuzzy, so is this pterosaur apart from the wing membranes.

Figure 2. NJU-57003 insitu. Even though the photo is fuzzy, so is this pterosaur apart from the wing membranes.

Yesterday Unwin and Martill 2020 
argued that pterosaurs did not have protofeathers. They said, any feathery-looking remains are decomposing fibers shed from the wings. They note that bristle-like integumentary structures do fringe the jaws of CAGS-Z070, but they do not concede any sort of homology other than to call the bristles ‘bristles’.

Yesterday Yang et al. 2020
replied to Unwin and Martill 2020, defending their hypothesis. “In our [2019] paper, we explored the morphology, ultrastructure and chemistry of the dermal structures of pterosaurs and showed that they probably had a common evolutionary origin with the integumentary structures seen widely in dinosaurs (including birds), their close relatives.” 

Their first sentence is wrong. As long-time readers are tired of hearing by now, Peters 2000, 2007 tested the pterosaur – dinosaur relationship by adding taxa. The added taxa attracted pterosaurs away from dinosaurs and nested them in a new and overlooked third clade of lepidosaurs, the Tritosauria, of which late surviving Huehuecuetzpalli is a basal member.

Yang et al. 2020 remind us,
“all four pycnofibre types are morphologically identical to structures already described in birds and non-avialan dinosaurs, not only in terms of gross morphology but also in their ultrastructure and chemistry, including melanosomes and chemical evidence for keratin; collectively, thesefeatures are consistent with feathers.”

Or hair. Or scales. Does anyone else see Yang et al. “Pulliing a Larry Martin“? The first thing Yang et al. should do is establish the relationship of pterosaurs with more parsimonious outgroups. They should know convergence is rampant within the Vertebrata and pterosaurs have never nested with dinosaurs whenever other candidates have been offered.

“Mapping these data onto a phylogeny yields a single evolutionary origin for feathers minimally in the avemetatarsalian ancestor of both pterosaurs and dinosaurs.”

That’s what happens when you omit data and citations. Professor Michael Benton is on the list of authors. This is not the first time Benton has omitted data and citations. You might remember when Hone and Benton 2008, 2009 were going to test competing hypotheses of relationship of pterosaurs. They reported they would test the archosaur hypothesis of Bennett 1996 versus the non-archosaur hypothesis of Peters 2000. Peters tested four prior hypotheses (including Bennett 1996) by simply adding Longisquama (Fig. 5), Cosesaurus, Sharovipteryx, and Langobardisaurus (Fig. 6), all of which attracted pterosaurs to their clade. Several of these added taxa have pterosaur-like fibers on their bodies (Fig. 5). When the anticipated results did not go their way, Hone and Benton 2009 deleted all reference to Peters 2000 and wrote that Bennett 1996 had come up with both competing hypotheses.

Getting back to the Reply from Yang et al. 2020:
“In their comment, Unwin and Martill [2020] assert that the branched integumentary structures that we identified are not feathers or even pycnofibres. They make five arguments in favour of their point of
view:”

  1. “superposition or decomposition of composite fibre-like structures or aktinofibrils yields branched structures similar to those in the anurognathids;
  2. the anatomy and anatomical distribution of the anurognathid integumentary structures are consistent with aktinofibrils, but not pycnofibres;
  3. evidence for keratin and melanosomes is not indicative of pycnofibres but rather reflects contamination from epidermal tissue;
  4. the branching we reported is not consistent with exclusively monofilamentous coverings in other anurognathids; and
  5. homology of the branched integumentary structures with feathers cannot be demonstrated conclusively owing to the simple morphology of the former.”

“We refute all five of their arguments.”

The view from ReptileEvolution.com:
Apparently no one has noticed that anurognathids, like Jeholopterus (Fig. 3), are decidedly different than other pterosaurs in terms of the length and quantity of their feathery fluff. In this way, and many others, anurognathids resemble modern owls, predator birds capable of silent flight due to the fluffiness of the pelage.

It is also worth noting
that anurognathids leave no descendants after the Early Cretaceous. In any case, pterosaurs are not related to birds or dinosaurs or archosaurs or archosauriformes or archosauromorphs, as demonstrated in the large reptile tree (LRT, 1740+ taxa) which tests all candidates for dinosaur, bird and pterosaur ancestry back to headless Cambrian chordates.

Figure 4. Jeholopterus in dorsal view. Here the robust hind limbs, broad belly and small skull stand out as distinct from other anurognathids. Click to enlarge.

Figure 3. Jeholopterus in dorsal view. Here the robust hind limbs, broad belly and small skull stand out as distinct from other anurognathids. Click to enlarge.

A figure caption from Unwin and Martill 2020
(Fig. 4) reports, “The inner region of the cheiropatagium adjacent to the body anterior to the pelvis. The dark, slightly granular epidermal surface of the integument (et) covering the torso (t) contrasts with the remarkably thin epidermal surface (ep) of the integument forming the proximal region of the cheiropatagium (c). Much of the epidermis covering the cheiropatagium has been lost, exposing closely packed and aligned aktinofibrils (ak) now slightly decayed. On the far left, much of the cheiropatagium has been pulled away, leaving a few incomplete aktinofibrils and numerous fine fibrils (fb) from which they were composed.”

This is the PIN–2585/36 specimen of Sordes pilosus, which Unwin has not shown in its entirety—ever. The proximal membrane (yellow) is the left fuselage fillet (see Fig. 3), which disproves the batwing hypothesis championed by Unwin and other PhDs. Unwin and Martill say the fine fibrils at left have been ‘pulled away’. I know of no fossil processes that ‘pull’ fine fibrils away from their original insertion points.

Other Sordes specimens have been misinterpreted by Unwin since Unwin & Bakhurina 1994. Peters 1995 argued against the bat-wing interpretation offered by Unwin & Bakhurina 1994 further described nine years ago here.

Figure 4. From Unwin and Martill 2020, colors, arrows and inset added. This is all that has ever been published of PIN-2585/36, a purported Sordes specimen. Given the few clues this appears to be the left fuselage fillet (see Fig. 3), which means this is why Unwin is only showing part of it because, if so, this disproves the batwing hypothesis championed by Unwin and other PhDs.

Figure 4. From Unwin and Martill 2020, colors, arrows and inset added. This is all that has ever been published of PIN-2585/36, a purported Sordes specimen. Given the few clues this appears to be the left fuselage fillet (see Fig. 3), which means this is why Unwin is only showing part of it because, if so, this disproves the batwing hypothesis championed by Unwin and other PhDs.

Yang et al. 2020 conclude:
“In light of this, the most parsimonious interpretation of the simple and branched integumentary appendages in the anurognathid pterosaurs remains our original conclusion that they are feathers.”

This conclusion is not supported by the LRT. Taxon inclusion would have helped Yang et al. 2020. Unwin and Martill 2020 are likewise not correct. They should have shown the same evidence that Yang et al. presented was incorrect, rather than showing their own evidence, which does not support their position.

An online article posted on Phys.org
cites U of Leicester and U of Portsmouth (England) workers. David Unwin and David Martill who claim pterosaurswere in fact bald.”

The article reports, “Feathered pterosaurs would mean that the very earliest feathers first appeared on an ancestor shared by both pterosaurs and dinosaurs, since it is unlikely that something so complex developed separately in two different groups of animals.”

Unlikely ≠ impossible. Just cite the LRT where convergence is rampant. Adding taxa is something paleontologists have been loathe to do for the last twenty years since Peters 2000 moved pterosaurs away from dinosaurs and 13 years since Peters 2007 moved pterosaurs into lepidosaurs. But let’s move on…

The article then states, 
“It would also suggest that all dinosaurs started out with feathers, or protofeathers but some groups, such as sauropods, subsequently lost them again—the complete opposite of currently accepted theory.” 

Once again, add taxa to determine where feathers, or protofeathers, first appeared in tetrapods and if there was a second genesis within the clade.

The article then states,
“The evidence rests on tiny, hair-like filaments, less than one tenth of a millimeter in diameter, which have been identified in about 30 pterosaur fossils. Among these, Yang and colleagues were only able to find just three specimens on which these filaments seem to exhibit a ‘branching structure’ typical of protofeathers.”

Evidence from 30 or just 3 pterosaurs is considerable. Nevertheless, all prior authors omit the pre-pterosaurs (Cosesaurus, Oculudentavis, Sharovipteryx, Longisquama, Fig. 5) most of which have epidermal membranes and fibers. These taxa (Fig. 6) nest between pterosaurs and the lepidosaur Huehuecuetzpalli.

Longisquama in situ. See if you can find the sternal complex, scapula and coracoid before looking at figure 2 where they are highlighted.

Figure 5. Longisquama in situ. See if you can find the sternal complex, scapula and coracoid before looking at figure 2 where they are highlighted.

The Phys.org article then states,
“Unwin and Martill propose that these are not protofeathers at all but tough fibers which form part of the internal structure of the pterosaur’s wing membrane, and that the ‘branching’ effect may simply be the result of these fibers decaying and unraveling.”

Professor Unwin said:
“The idea of feathered goes back to the nineteenth century but the fossil evidence was then, and still is, very weak. Exceptional claims require exceptional evidence—we have the former, but not the latter.”

The evolution of the pterosaur tail beginning with a basal lizard, Huehuecuetzpalli.

Figure 6. The evolution of the pterosaur tail beginning with a basal lizard, Huehuecuetzpalli.

Professor Martill noted:
that either way, palaeontologists will have to carefully reappraise ideas about the ecology of these ancient flying reptiles. Martill said, “If they really did have feathers, how did that make them look, and did they exhibit the same fantastic variety of colors exhibited by birds. And if they didn’t have feathers, then how did they keep warm at night, what limits did this have on their geographic range, did they stay away from colder northern climes as most reptiles do today. And how did they thermoregulate? The clues are so cryptic, that we are still a long way from working out just how these amazing animals worked.”

As a final note, let’s remember, that when it comes to pterosaur origins, 
workers have been keeping their blinders on for decades. Not sure why, but what results is the current misunderstanding expressed by Yang et al. 2020 AND Unwin and Maritill 2020.


References
Peters D 1995. Wing shape in pterosaurs. Nature 374, 315-316.
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.
Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29: 1327-1330
Unwin DM and Bakhurina NN 1994. Sordes pilosus and the nature of the pterosaur flight apparatus. Nature 371, 62–64.
Unwin DM and Martill DM 2020. No protofeathers on pterosaurs. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-020-01308-9
Yang Z et al. 2019. Pterosaur integumentary structures with complex feather-like branching. Nature Ecology & Evolution 4, 24–30 (2019).
Yang Z et al. 2020. Reply to: No protofeathers on pterosaurs. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-020-01308-9

https://phys.org/news/2020-09-naked-prehistoric-monsters-evidence-reptiles.html?fbclid=IwAR0YSjtIfZRBUiD6W3b1jwnhzWPFe_eXBE4ABFa2D8QXRCI8GNIfxNQEEs4

From today’s dml.cmnh.org:

“If you can’t cope with the idea of naked pterosaurs, don’t watch my SVP presentation…”

––––––––––––––––––––––––––––––––––––––––––––––
Dr David M Unwin
Associate Professor (Museum Studies)
School of Museum Studies, University of Leicester
t: +44 116 252 3947   e: dmu1@le.ac.uk

What is Leptostomia? So little to work with…

A new genus and species of little pterosaur
from the Early Cretaceous of Morocco, Leptostomia begaaensis (Smith et al. 2020; Figs. 1–3), is based on two, little 3D pieces of rostrum (FSAC-KK 5075) and mandible (FSAC-KK 5076) originally considered to belong to a new kind of azhdarchoid (an invalid polyphyletic clade in the large pterosaur tree; LPT, 251 taxa), that traditionally, but mistakenly includes unrelated tapejarids and azhdarchids. As usual, simply adding traditionally or specifically omitted taxa clarifies interrelationships.

Figure 1. At about twice life size, these are jaw portions from Leptostomia in several views.

Figure 1. At about twice life size, these are jaw portions from Leptostomia in several views.

The affinities of the jaw segments remain ‘unclear’
according to the authors. Once again this was due to taxon exclusion.

Figure 2. Photo of the Leptostomia rostrum fragment in several views. Colors added here.

Figure 2. Photo of the Leptostomia rostrum fragment in several views. Colors added here. Premaxilla = yellow. Maxilla = green. Vomer = purple.

Unfortunately 
Smith et al. omitted the tall, slender ctenochasmatid, Gegepterus (Fig. 3,4) from their comparables list. Gegepterus has a similar rostrum and mandible. Both are similar in size and (Fig. 4) both are from Early Cretaceous strata, one from Morocco, the other from China.

Figure 3. Leptostomia compared to coeval Gegepterus (see figure 4).

Figure 3. Leptostomia compared to coeval Gegepterus at the same scale  (see figure 4).

Most pterosaurs,
including azhdarchids and tapejarids, have a taller than wide rostrum along with a narrow premaxilla ascending process that extends to the dorsal orbit.

Figure 4. Similar to azhdarchids, Gegepterus was a tall, slender ctenochasmatid with long jaws, neck and legs.

Figure 4. Similar to azhdarchids, except for size, Gegepterus was a tall, slender ctenochasmatid with long jaws, neck and legs for an overall small pterosaur. Here it is shown 3/5 original size.

By contrast,
the Leptostomia rostrum has a wider rostrum and a wider premaxilla overlapping it. Worth remembering: both the rostrum and mandible fragments are less than 1cm wide on this small specimen and genus.

Figure 5. Leptostomia rostrum palatal view. Vomer = purple ridge. Mx = maxilla. Tiny remnant alveoli appear to be present on the lateral palatal ridge.

Figure 5. Leptostomia rostrum palatal view. Vomer = purple ridge. Mx = maxilla. Tiny remnant alveoli appear to be present on the lateral palatal ridge, overlooked by Smith et al.

Most ctenochasmatids
have long slender teeth arising from the jaw rims. No such teeth are preserved with or were collected with Leptostomia, A close view (Fig. 5) shows a line of small ovals that could be slender tooth alveoli. Or teeth may indeed be absent in this taxon.

Wiki authors describing Gegepterus in Wikipedia note:
“This is the first uncontroversial report of the Ctenochasmatidae from the Yixian Formation, as the fossils of other assumed ctenochasmatids have not preserved the dentition.”

Smith et al. note,
Leptostomia differs from other edentulous pterosaurs in possessing a remarkably low rostral lateral angle, endowing it with a very long and slender beak. Its lateral angle is also very low when compared with toothed pterosaurs with only some ctenochamatids having a similarly low lateral angle.”

Smith et al. propose a poorly informed guess,
“The new pterosaur adds to the remarkable diversity of pterosaurs known from the mid-Cretaceous, and suggests that pterosaur diversity remained under sampled.” No it doesn’t. Leptostomia looks like an omitted taxon, Gegepterus.

In the LPT there are few to no morphological gaps largely because it employs a much larger taxon list than any published by PhD workers and their students who refuse to include small taxa, more than one specimen assigned to a genus and valid pterosaur outgroups in their analyses. Same for the LRT.

Quetzalcoatlus scraping bottom while standing in shallow water.

Figure 6. Quetzalcoatlus scraping bottom while standing in shallow water.

Smith et al. state,
“The proposed probe-feeding strategy suggested by the rostrum morphology of Leptostomia has not previously been documented for the Pterosauria.” This is false. Just google, “pterosaur + probe” and a long list will appear. And there’s always this image (Fig. 6) of the man-sized Quetzalcoatlus probing, which has been online for awhile, following ‘suggestions’ from Langston 1981.


References
Langston W Jr 1981. Pterosaurs. Scientific American: 244,:122–126.
Smith RE, Martill DM, Kao A, Zouhri S and Longrich N 2020. A long-billed, possible probe-feeding pterosaur (Pterodactyloidea: ?Azhdarchoidea) from the mid-Cretaceous of Morocco, North Africa, Cretaceous Research, https://doi.org/10.1016/j.cretres.2020.104643.

wiki/Leptostomia
wiki/Gegepterus

The rest of Lonchodraco probably looks like this large unnamed ornithocheird

Only the deep toothy jaw tips,
of the pterosaur Lonchodraco giganteus (Hooley 1914; Rodrigues & Kellner 2013; NHMUK PV 39412; originally Pterodactylus giganteus Bowerbank 1846; Fig. 1) are known. Ever wonder what the rest of this pterosaur looked like?

Well,
the 174-year wait is over.

Figure 1. Lonchodraco jaw tips. Colors added here.

Figure 1. Lonchodraco jaw tips. Colors added here. For the rest of this genus, see figure 2. The nasal (pink) is laminated between the premaxilla (yellow) and maxilla (green). The jugal (blue) also makes an appearance.

What little is known of Lonchodectes turns out to look like
the (so far) unnamed large ornithocheirid, SMNK PAL 1136 (Fig. 2) one of the largest of all flying pterosaurs. The very few parts they have in common are virtually identical, except for size (note the scale bars provided).

Figure 2. The unnamed giant ornithocheirid, SMNK PAL 1136 has a rostrum quite similar to that of Lonchodectes.

Figure 2. The unnamed giant ornithocheirid, SMNK PAL 1136 has a rostrum quite similar to that of Lonchodectes. With such giant wings, soaring over wave tops would have been ideal, dipping occasionally to feed without getting wet.


As one of the largest flying pterosaurs,

SMNK PAL 1136 (Figs. 2, 3) presents no vestigial terminal wing phalanges. No hyper-elongated neck cervicals are present. This pterosaur was built to soar like a big pelican.

Sorry, giant azhdarchids lovers 
(Fig. 3). Those were not volant, as we learned earlier here. They grew to be so big AFTER they became flightless, like flightless birds do. Giant azhdarchids DO have vestigial wing phalanges and a hyper-elongated neck.

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

Figure 3. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale.

Earlier workers 
did not match Lonchodraco to the SMNK PAL 1136 specimen. Earlier workers did not name the SMNK specimen. Perhaps someone is working on that specimen at present and other workers are giving him/her the honor/duty of naming it.

Wonder if
the Lonchodraco name will stick to the SMNK specimen?

Recently, Martill et al. 2020 took a close look
at the foramina in the jaw tips of Lonchodraco and thought they indicated enhanced sensitivity of the rostrum tip, which implied tactile feeding. With such giant wings, soaring over wave tops would have been likely, dipping occasionally to feed without getting the wings wet.

Odd that the top workers at the top universities
have decided to spend their time examining tiny pits on a broken 174-year-old pterosaur snout while ignoring the origin of pterosaurs… while ignoring many dozen complete pterosaurs that should be in phylogenetic analysis… while ignoring the lepidosaurs that gave rise to the ancestors of pterosaurs. Unfortunately, that’s the world academics live in today. They keep trying to not upset the lectures and textbooks from which they make their living. Apparently if academics focus on the details they won’t have to worry about the big picture. No one will ever know the difference if no one points out the elephant in the room.


References
Averianov AO 2020. Taxonomy of the Lonchodectidae (Pterosauria, Pterodactyloidea). Proceedings of the Zoological Institute RAS. 324 (1): 41–55. doi:10.31610/trudyzin/2020.324.1.41
Bowerbank JS 1846. On a new species of pterodactyl found in the Upper Chalk of Kent (Pterodactylus giganteus). Quarterly Journal of the Geological Society of London. 2: 7–9.
Bowerbank JS 1848. Microscopical observations on the structure of the bones of Pterodactylus giganteus and other fossil animals”. Quarterly Journal of the Geological Society. 4: 2–10.
Martill DM, Smith RE, Longrich N and Brown J 2020. Evidence for tactile feeding in pterosaurs: a sensitive tip to the beak of Lonchodraco giganteus (Pterosauria, Lonchodectidae) from the Upper Cretaceous of southern England. Cretaceous Research
Available online 3 September 2020, 104637 Cretaceous Research https://doi.org/10.1016/j.cretres.2020.104637
Rodrigues T and Kellner A 2013. Taxonomic review of the Ornithocheirus complex (Pterosauria) from the Cretaceous of England. ZooKeys. 308: 1–112. doi:10.3897/zookeys.308.5559

wiki/Lonchodraco

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