Enigma pterosaur wing bone from Late Campanian Utah

Farke 2021
brings us a large ‘pterosaur limb bone’ (Fig. 1) from the Late Cretaceous of Utah. The author guessed the bone was an ulna, but could not determine which end was proximal.

Figure 1. Radius RMA 22574 from Farke 2021.

Figure 1. Ulna RMA 22574 from Farke 2021. Distal is at bottom.

From the abstract
“A large pterosaur bone from the Kaiparowits Formation (late Campanian, ~76–74 Ma) of southern Utah, USA, is tentatively identified as an ulna, although its phylogenetic placement cannot be precisely constrained beyond Pterosauria. The element measures over 36 cm in preserved maximum length, indicating a comparatively large individual with an estimated wingspan between 4.3 and 5.9 m, the largest pterosaur yet reported from the Kaiparowits Formation.”

That tentative identity as an ulna is confirmed here.  
Other than its more robust width and overall size, the bone is a good match for the ulna in the more completely known Triebold specimen of Pteranodon, NMC41-358 (Fig. 3). The overall size and relative length vs. width of RMA 22574 identifies this as a large Pteranodon (Fig. 2), perhaps the largest by a few percent, rather than a small azhdarchid (Fig. 4).

So, contra Farke 2021,
this specimen can be precisely constrained rather precisely beyond Pterosauria. It just takes a little comparative anatomy and taxon inclusion. Farke employed only one Pteranodon specimen (FHSM 184) for comparison, perhaps not realizing that no two known taxa are identical, even in the post-crania (Fig. 2), and others demonstrate a wide variation in size and morphology. By the way, FHSM 184 is a large solitary metacarpal 4.

Figure 2. The largest Pteranodon post-crania compared to RMA 22574, slightly larger than the largest.

Figure 2. The largest Pteranodon post-crania compared to RMA 22574, slightly larger than the largest.

A little repair work
to the broken proximal end (elbow) helps complete the match between RMA 22574 and NMC41-358 (Fig. 3).

Figure 2. Comparing RMA 22574 with the smaller and more gracile NMC41-358.

Figure 3. Comparing RMA 22574 with the smaller and more gracile NMC41-358 scaled to the same length.

A selection of Pteranodon post-crania
can be seen to scale here and one of the largest is shown here (Fig. 2). Note the relatively shorter, broader antebrachia (= radius + ulna) in the largest, latest Pteranodon species relative to the humerus (Fig. 2 upper right). The relatively shorter, more robust, largest antebrachium with the characters of RMA 22574 is restricted to large, late Pteranodon specimens.

Figure 3. RMA 22754 compared to Quetzalcoatlus sp. which has a more slender radius.

Figure 4. RMA 22754 compared to Quetzalcoatlus sp. which has a more slender radius.

Comparisons to appropriately sized azhdarchids
(Fig. 4) do not match as well. These tend to have a more gracile, hourglass appearance.


References
Farke AA 2021. A large pterosaur limb bone from the Kaiparowits Formation (late Campanian) of Grand Staircase-Escalante National Monument, Utah, USA. PeerJ 9:e10766 https://doi.org/10.7717/peerj.10766

reptileevolution.com/pteranodon-skulls.htm
reptileevolution.com/pteranodon-postcrania.htm

Pterosaur tooth scratches and diets

Bestwick et al. 2020 wrote:
“Pterosaurs, the first vertebrates to evolve active flight, lived between 210 and 66 million years ago. They were important components of Mesozoic ecosystems, and reconstructing pterosaur diets is vital for understanding their origins, their roles within Mesozoic food webs and the impact of other flying vertebrates (i.e. birds) on their evolution.

Vital? Is that what they call ‘hyperbole?’ For their outgroup, the authors employ the basal bipedal crocodylomorph with tiny hands and no toe 5, Scleromochlus, so… so far tooth scratches are not proving ‘vital for understanding their origins.‘ They ignored citations, scratches and common sense. Not a good start.

“However, pterosaur dietary hypotheses are poorly constrained as most rely on morphological-functional analogies. Here we constrain the diets of 17 pterosaur genera by applying dental micro wear texture analysis to the three-dimensional sub-micrometre scale tooth textures that formed during food consumption. We reveal broad patterns of dietary diversity (e.g. Dimorphodon as a vertebrate consumer; Austriadactylus as a consumer of ‘hard’ invertebrates) and direct evidence of sympatric niche partitioning (Rhamphorhynchus as a piscivore; Pterodactylus as a generalist invertebrate consumer).

That’s refreshing! Delivering results in an abstract. Unfortunately, there’s nothing new here and Nature papers usually break new ground.

“We propose that the ancestral pterosaur diet was dominated by invertebrates and later pterosaurs evolved into piscivores and carnivores, shifts that might reflect ecological displacements due to pterosaur-bird competition.”

Again, nothing new here.

The authors downplay fossilized stomach contents 
due to their limited preservation, so they put greater emphasis on the scratched enamel of pterosaur teeth. Comparisons are made to extant reptile tooth scratches from crocs and monitor lizards. Iguanids are not mentioned. The word ‘arboreal’ is likewise not found in the text.

Figure 3. Dsungaripterus single teeth at the tips of the jaws. Phylogenetically these began with Germanodactylus (Fig. 4).

Figure 1. Dsungaripterus single teeth at the tips of the jaws. Phylogenetically these began with Germanodactylus (Fig. 4).

Those tooth scratches are rather indistinct.
Odd that the authors downplay stomach contents in pterosaurs (based on their rarity) given the headline of their paper. So-called toothless pterosaurs are ignored despite the fact that the tips of beaks are teeth (Fig. 1). Oddly, so are dsungaripterids (Fig. 1) and ctenochasmatids, both of which have marginal teeth.

Pterodaustro adult with manual digit 3 repaired.

Figure 2. Pterodaustro adult with manual digit 3 repaired.

Juvenile diets are not mentioned appropriately
Rather phylogenetically miniaturized adult basal Rhamphorhynchus specimens are considered juveniles, forgetting the fact that all pterosaurs mature isometrically, as demonstrated by Pterodaustro (Fig. 2) and Zhejiangopterus ontogenetic series. We also have one juvenile Rhamphorhynchus, identical to larger adult.


References
Bestwick J, Unwin DM, Butler RJ and Purnell MA 2020. Dietary diversity and evolution of the earliest flying vertebrates revealed by dental micro wear texture analysis. Nature Communications https://doi.org/10.1038/s41467-020-19022-2

Bestwick J, Unwin DM, Butler RJ, Henderson DM and Purnell MA 2018. Pterosaur dietary hypotheses: a review of ideas and approaches. Biological Reviews https://doi.org/10.1111/brv.12431

Caupedactylus ybaka (Kellner 2012) enters the LPT

Kellner (2012, 2013) described
the skull of an Early Cretaceous sinopterid pterosaur, Caupedactylus ybaka (MN 4726-V, Fig. 1). The skull is about forty-six centimetres long. (Hope I got this right this time).

Earlier the same skull was posted online.

Figure x. Caupedactylus in situ and restored by sculptors.

Figure x. Caupedactylus in situ and restored by sculptors. Or a different specimen.

New Tapejarid-Tupuxuarid skull.

Figure 1. New Tapejarid-Tupuxuarid skull now named Caupedactylus.

Bones colorized in this tapejarid / tupuxuarid.

Figure 2. Bones colorized in this tapejarid / tupuxuarid, named Caupedactylus.

Abstract
“A new unusual tapejarid pterosaur from the Early Cretaceous Romualdo Formation (Araripe Basin, Brazil) is described, based on a skull, lower jaw and some postcranial elements. Caupedactylus ybaka gen. et sp. shows the typical high nasoantorbital fenestra of the Thalassodrominae but lacks a palatal ridge, and shares with the Tapejarinae several features, including a downturned rostral end, allowing its allocation to that clade.”

The new skull compared to other tapejarids. Click to enlarge.

Figure 2. Click to enlarge. The rising size of the tapejaridae.

Abstract continues
“Furthermore, the new species differs in having an anteriorly and posteriorly expanded premaxillary sagittal crest, the lacrimal process of the jugal strongly inclined, and a slit-like postpalatine fenestra, among other characters. The region of the left jugal-quadratojugal-quadrate shows a pathology that is likely the result of an infection. The lateral surface of the premaxillary crest presents grooves that were interpreted in other pterosaurs as impressions of blood vessels, corroborating growing evidence that cranial crests could have been involved in thermoregulation.”

“Also, the new species has a well-preserved palate with a large palatine forming the anterior region of the choanae and the postpalatine fenestra and a secondary subtemporal fenestra. Since the latter has been regarded as unique to non-pterodactyloids, its occurrence in Caupedactylus demonstrates that the evolution of palatal region in pterosaurs is more complex than previously thought.”

Perhaps to no one’s surprise, this specimen nested in 2013 in the large pterosaur tree (LPT) between Sinopterus dongi and Tupandactylus.


References
Campos HBN and Headden JA 2013. A review of Tupuxuara deliradamus (Pterosauria, Azhdarchoidea, Thalassodromidae) from the Early Cretaceous Romualdo Formation of Brazil. International Symposium on Pterosaurs – Rio Ptero 2013.
Elgin RA 2015. Paleobiology, Morphology and Flight Characteristics of Pterodactyloid Pterosaurs. Dissertation, University of Heidelberg.
Kellner AWA 2012. A new unusual tapejarid (Pterosauria, Pterodactyloidea) from the Early Cretaceous Romualdo Formation, Araripe Basin, Brazil. Cambridge University Press 103 (3-4) The Full Profession: A Celebration of the Life and Career of Wann Langston, Jr., Quintessential Vertebrate Palaeontologist September 2012 , pp. 409-421.
Kellner AWA 2013. A new unusual tapejarid (Pterosauria, Pterodactyloidea) from the Early Cretaceous Romualdo Formation, Araripe Basin, Brazil. Earth and Environmental Science Transactions of the Royal Society of Edinburgh 103(3-4): 409-421.
Manzig PC et al. (10 co-authors) 2014. Discovery of a Rare Pterosaur Bone Bed in a Cretaceous Desert with Insights on Ontogeny and Behavior of Flying Reptiles. PLoS ONE 9(8): e100005.
Martill DM and Naish D 2006. Cranial Crests Development in the Azhdarchoid Pterosaur Tupuxuara, With Review of the Genus and Tapejarid Monophyly. Palaeontology 49(4): 925-941.

wiki/Caupedactylus
pterosaurheresies.wordpress.com/2013/06/06/tapejarid-or-tupuxuarid/

A quick look at the original Tapejara skull

Short one today
told mostly in pictures.

Topic: Simplification. 
Get rid of the extraneous data to better see and understand the basics.

Figure 1. Just take out everything that isn't this side of Tapejara. Rearrange the parts for best fit. Make a guess for the missing parts and this is what you get.

Figure 1. Just take out everything that isn’t this side of Tapejara. Rearrange the parts for best fit. Make a guess for the missing parts and this is what you get.

In this case
the skull of the original Tapejara fossil (Fig. 1) is trimmed back to just the basics and slightly shifted to fit. Missing tips are added based on phylogenetic bracketing.

Figure 4. Click to enlarge. The Tapejaridae arise from dsungaripterids and germanodactylids.

Figure 2. Click to enlarge. Tiny Tapejaridae arise from dsungaripterids and germanodactylids, then grow larger phylogenetically.

Tapejara wellnhoferi
(Kellner 1989; 108 mya, Early Cretaceous) was immediately recognized as something quite different when first discovered. Compared to other specimens, this one appears to have no sharp premaxilla, likely due to taphonomic loss.


References
Eck K, Elgin RA and Frey E 2011. On the osteology of Tapejara wellnhoferi KELLNER 1989 and the first occurrence of a multiple specimen assemblage from the Santana Formation, Araripe Basin, NE-Brazil. Swiss Journal of Palaeontology, doi:10.1007/s13358-011-0024-5.
Kellner AWA 1989. A new edentate pterosaur of the Lower Cretaceous from the Araripe Basin, northeast Brazil. Anais da Academia Brasileira de Ciências 61, 439-446.

wiki/Tapejara

 

Sinopterus? or Huaxiapterus? It gets confusing…

A kind reader alerted me to a misidentification here.
The grayscale image (Fig. x) is the ZMNH M 8131 specimen of Huaxiapterus. When a higher resolution image becomes available I will return to this specimen and edit the copy. With that in mind… here is the original blogpost, awaiting an edit.

Figure x. Huaxiapterus ZMNH-M-8131 specimen.

Figure x. Huaxiapterus ZMNH-M-8131 specimen.

 

Thank goodness
for museum numbers.

Today the ZMNH M 8131 specimen first attributed to
Huaxiapterus corollatus (Lü et al. 2006) then renamed Sinopterus corollatus (Zhang et al. 2019; Figs. 1, 2) enters the the large pterosaur tree (LPT, 255 taxa) basal to tapejarids, derived from the Sinopterus atavismus specimen nesting basal to dsungaripterids.

Figure 1. Huaxiapterus corollatus ZMNH M 8131 reconstructed. An alternate m4.1 is provided that looks more like a m4.1 than a metacarpal 4.

Figure 1. Huaxiapterus corollatus ZMNH M 8131 reconstructed. An alternate m4.1 is provided that looks more like a m4.1 than a metacarpal 4.

Sometimes specimens are reassembled slightly wrong.
In this case several long bones were accidentally reversed end-to-end in this otherwise stunning mount. One never knows what the original fossil looked like prior to reassembly. We don’t want to call these ‘fakes’. We do want to be aware of errors and artistic reconstructions as much as is possible.

Figure 2. The ZMNH specimen in situ and somewhat corrected for original perspective issues. The correction makes the wings the same length.

Figure 2. The ZMNH specimen in situ and somewhat corrected for original perspective issues. The correction makes the wings the same length. Be wary of such wonderful-looking fossils. This specimen appears to have been reassembled. Some long bones are reversed end-to-end, which do not affect scoring.

Sinopterus – Huaxiapterus corollatus (Lü et al. 2006; Early Cretaceous, ZMNH M 8131) is another largely complete specimen with confusing nomenclature. This taxon nests at the base of the Tapejara, basal to the Aathal specimen (below). The pelvis is missing. The sternum is among the largest of all pterosaurs. The cervicals are longer creating a taller pterosaur.

From the Lü et al. abstract:
“A new species of tapejarid pterosaur, Huaxiapterus corollatus sp. nov. is erected on the basis of a nearly complete skull and postcranial skeleton from the Lower Cretaceous Jiufotang Formation of Liaoning Province, China. Huaxiapterus corollatus sp. nov. is characterized by a hatchet-shaped rectangular process on the premaxilla, whose short axis is perpendicular to the anterior margin of the premaxillae. Except for this process, other characters of the skull such as the breadth of the snout between the anterior margin of the nasoantorbital fenestra and the anterior margin of the premaxilla are similar to that of Huaxiapterus jii.”

Figure 3. Huaxiaptrus iii and Huaxiapterus corollatus to scale. These two do not nest next to one another in the LPT.

Figure 3. Huaxiaptrus iii and Huaxiapterus corollatus to scale. These two do not nest next to one another in the LPT.

The Lü et al. abstract continues
“Huaxiapterus and a second Chinese tapejarid, Sinopterus, share several unique cranial characters in common with Tapejara and these three genera appear to be more closely related to each other than to other azhdarchoids.

In the LPT azhdarchids nest with dorygnathids, not tapejarids. Adding these taxa missing from prior studies makes this inevitable.

“The Chinese tapejarids (Sinopterus and Huaxiapterus) have relatively elongate skulls and weakly developed cranial crests and seem to be less derived than Tapejara, with its shorter, deeper skull and large cranial crest. Tupuxuarids (Tupuxuara and Thalassodromeus) have often been associated with tapejarids in the family Tapejaridae, but this relationship is controversial because some phylogenetic analyses have supported the pairing of tupuxuarids with Azhdarchidae.”

Adding taxa moves Azhdarchidae away from tupuxuarids.

Figure 4. Tapejaridae in the LPT.

“We propose that Tapejaridae be restricted to Tapejara, Sinopterus and Huaxiapterus.”

The LPT does not support that proposal (Fig. 4). The Tapejaridae remains a monophyletic clade in the LPT derived from dsungaripterids, shenzhoupterids and earlier, germanodactylids… not azhdarchids.


References
Lü JC, Jin XS, Unwin DM, Zhao LJ, Azuma Y and Ji Q 2006. A new species of Huaxiapterus Pterosauria: Pterodactyloidea from the Lower Cretaceous of western
Liaoning, China with comments on the system atics of tapejarid pterosaurs. Acta Geol Sinica English 80: 315-326.
Zhang X, Jiang S, Cheng X and Wang X 2019. New material of Sinopterus (Pterosauria, Tapejaridae) from the Early Cretaceous Jehol Biota of China. Anais da Academia Brasileira de Ciencias 91(2):e20180756. DOI 10.1590/0001-3765201920180756.

wiki/Sinopterus
wiki/Huaxiapterus
reptileevolution.com/tapejaridae.htm

SVP abstracts 26: Pterosaur fibers or lack thereof, again

Unwin and Martill 2020
published on this abstract earlier last year and this year (2020).

“Fiber-like structures are frequently preserved in association with fossilized remains of the pterosaur integument. Several fiber types have been recognized. Among the commonest are aktinofibrils, typically 40–100+ μm in breadth and present throughout the flight patagia, exhibiting the same patterns of alignment across Pterosauria.

“Occasionally partially mineralized in distal regions of the patagia, aktinofibrils were composite, helically-wound structures composed of much finer filaments a few microns in diameter.

“Comparable in size to aktinofibrils, but less common, are single-stranded, hair-like pycnofibers, seemingly branched in two specimens of the anurognathid Jeholopterus, that supposedly adorned parts of the cranium, neck, and body. Fiber-like structures have also been reported in cranial crests, foot webs, and tail flaps. The identity, homology, composition, and function of integumentary fibers is fiercely disputed.”

‘Fiercely’? Hyperbole. This issue was just raised by Unwin and Martill and I have yet to see their evidence. Here’s the evidence for pycnofibers on the fluffiest pterosaur of all, the owl-like holotype of Jeholopterus (Fig. 1) and a reconstruction of same (Fig. 2).

Figure 2. Wing and other extra dermal membranes surrounding Jeholopterus.

Figure 1. Wing and other extra dermal membranes surrounding Jeholopterus.

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

Unwin and Martill 2020 abstract continues:
“This study aimed to resolve these issues through analysis of 150+ specimens where the integument is preserved, representing >25% of known pterosaur species, 15 of the 20 principal lineages, and almost the entire temporal range of the clade. Details of the macro- and microstructure of fibers was obtained using light, UV and laser-UV photography, and binocular and scanning electron microscopy.”

Missing from their taxon list are any outgroups of the Pterosauria (Cosesaurus, Sharovipteryx and Longisquama, Fig. 3), all of which also have extradermal membranes and fibers, some of which form precursor wing fibers (Peters 2009).

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

Figure 3. Longisquama in situ. See if you can find the sternal complex, scapula and coracoid before looking at figure 2 where they are highlighted.

Unwin and Martill 2020 abstract continues:
“Results of this study provide broad support for a new model in which pterosaur integumentary fibers of all types had a single common origin: dermal collagen. This idea is consistent with:

  1. exceptionally preserved examples of cranial crests, wing membranes, and integument associated with the neck and body, which demonstrate that fibers were embedded within the integument, and formed part of the dermis;
  2. calcification of fibers in the cranial crest and, occasionally, in distal parts of the flight patagia;
  3. the composite construction of fibers, which were composed of much finer, helically-wound fibrils.

There’s no argument there. Nothing fiercely disputed. Everyone agrees.

“Multiple specimens with soft tissues preserved in four different preservational modes, show that the integument had a glabrous, fine granular, or even polygonal external texture. Aktinofibrils and other collagenous dermal fibres (e.g., in cranial crests and skin associated with the neck and body) exposed by decay of the remarkably thin epidermis have frequently been misinterpreted as pycnofibers.”

The word ‘misinterpreted’ here should have been the leading sentence followed by evidence. Not the penultimate one followed by no evidence. Unwin and Martill should have taken the strongest evidence against their hypothesis and knocked it down with evidence. They had the opportunity, and they were paid to do this, but failed to do their job.

Figure 2. Here is the Vienna specimen of Pterodactylus in situ and with matrix removed. Now compare this figure with figure 3, which shows the wings and uropatagia unfolding. There is no way to turn this into a deep chord wing membrane. And it decouples the forelimbs from the hind limbs.

Figure 4. Here is the Vienna specimen of Pterodactylus in situ and with matrix removed. Where are the pycnofibers here? I see skin, but no fibers. Then again, the fluffiness of Jeholopterus gave it owl-like silent flight characteristics not needed in a beach combing wader.

Unwin and Martill 2020 abstract continues:
“External fibers fringing the jaws of anurognathids may be an exception, although branching, reported in one specimen, is likely an artifact of preservation.”

Only this one extremely minor exception? Let’s talk about the other major exceptions (Figs. 1, 2). And let’s talk about the lack of similar fibers on wading pterosaurs like Pterodactylus (Fig. 4). The fact that Unwin and Martill got the wing membranes wrong and continue to deny the lepidosaur ancestry of pterosaurs lead one to distrust and discredit everything else they say (= invalid phylogenetic context). And that’s something that should never happen to a couple of pterosaur experts.


References
Peters D 2009. A reinterpretation of pteroid articulation in pterosaurs. Journal of Vertebrate Paleontology 29: 1327-1330
Unwin D and Martill D 2019. When the Mesozoic got ugly – naked, hairless, (and featherless) pterosaurs. SVPCA abstracts.
Unwin D and Martill D 2020. Identity, homology, and composition of fiber-like structures associated with the pterosaur integument. SVP abstracts 2020.

https://pterosaurheresies.wordpress.com/2019/10/02/unwin-and-martill-2019-find-pterosaurs-naked-and-ugly/

https://pterosaurheresies.wordpress.com/2020/09/30/naked-pterosaurs-or-feathered-phds-clash/

SVP abstracts 6: Dsungaripterus palate

This October 2020 abstract is identical
to one published in April 2020 as Chen et al. described the same Dsungaripterus palate (Fig. 1) in PeerJ. The following is a brief synopsis of that earlier post.

Figure 1. Dsungaripterus palate from Chen et al. 2020 with colors and diagrams (above) from Peters 2000 added. Note only a vestige remains of the lateral process of the palatine. The extent of the jugal is a guess here. Pink = pterygoid. Blue = palatine. Gold = ectopterygoid.  In Chen et al. the line leading toward the abbreviation pl points to the maxilla.

Figure 1. Dsungaripterus palate from Chen et al. 2020 with colors and diagrams (above) from Peters 2000 added. Note only a vestige remains of the lateral process of the palatine. The extent of the jugal is a guess here. Pink = pterygoid. Blue = palatine. Gold = ectopterygoid.  In Chen et al. the line leading toward the abbreviation pl points to the maxilla.

Chen et al. April 2020 cited
Osi et al. 2010, which we looked at earlier here. You might remember, Osi et al. thought they had discovered the true identity of palatal elements, but parenthetically acknowledged that Peters 2000 (Fig. 1) had done so a decade earlier. They did not realize others had also done so over a century before.

Prior to Peters 2000  
and ever since Williston (1902) and continuing through Huene 1914, Wellnhofer (1978, 1991) and Bennett (1991, 2001a,b), the solid palatal plate in pterosaurs had been traditionally considered the palatine. That was the orthodox point-of-view.

Virtually ignored,
Newton (1888), Seeley (1901 and Woodward (1902) reported that the solid palatal plate was an outgrowth of the maxilla, not the palatine. Unfortunately, I did not know those citations when Peters 2000 reported that the palatal plate actually originated from the maxilla. I thought I had discovered something! Rather, I had only confirmed work from a century earlier. Workers: it is important to expand your citation list so future workers will not overlook important papers, be they 20 years old or 120 years old.


References
Chen et al. (7 co-authors) 2020 (April). New anatomical information on Dsungaripterus weii Young, 1964 with focus on the palatal region. SVP Abstracts
Chen et al. (7 co-authors) 2020 (October). New anatomical information on Dsungaripterus weii Young, 1964 with focus on the palatal region. PeerJ 8:e8741 DOI 10.7717/peerj.8741

https://pterosaurheresies.wordpress.com/2020/04/03/dsungaripterus-palate-news-chen-et-al-2020/

Prior References from April 2020:
Bennett SC 1991. Morphology of the Late Cretaceous Pterosaur Pteranodonand Systematics of the Pterodactyloidea. [Volumes I and II]. – Ph.D. thesis, University of Kansas [Published by University Microfilms International/ProQuest].
Bennett SC 2001a, b. The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. Part I and 2. General description of osteology. – Palaeontographica, Abteilung A, 260: 1-153.
Chen et al. (7 co-authors) 2020. New anatomical information on Dsungaripterus weii Young, 1964 with focus on the palatal region. PeerJ 8:e8741 DOI 10.7717/peerj.8741
Newton ET 1888. On the skull, brain and auditory organ of a new species of pterosaurian (Scaphognathus Purdoni) from the Upper Lias near Whitby, Yorkshire. Philosphoical Transaction of the Royal Society, London 179: 503-537.
Osi A, Prondvai E, Frey E and Pohl B 2010. New Interpretation of the Palate of Pterosaurs. The Anatomical Record 293: 243-258.
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Seeley HG 1901. Dragons of the air. An account of extinct flying reptiles. – London, Methuen: 1-240.
Wellnhofer P 1978. Pterosauria. Handbuch der Paläoherpetologie, Teil 19.– Stuttgart, Gustav Fischer Verlag: 1-82.
Wellnhofer P 1991. The Illustrated Encyclopedia of Pterosaurs. London, Salamander Books, Limited: 1-192.
Williston SW 1902. On the skull of Nyctodactylus, an Upper Cretaceous pterodactyl. Journal of Geology 10:520–531.
Woodward AS 1902. On two skulls of Ornithosaurian Rhamphorhynchus. Annals of the Magazine Natural History 9:1.
Young CC 1964. On a new pterosaurian from Sinkiang, China. Vertebrata PalAsiatica 8: 221-256.

wiki/Dsungaripterus

Hone 2020 reviews anurognathid pterosaurs

Here’s a new paper from Dr. DWE Hone (2020).
Quoting Hone’s own publicity sheet regarding the paper, “there’s not a huge amount to talk about here since as it’s a review, it doesn’t contain too much that’s new.”

Even so,
Hone manages to promote invalid pterosaur myths, like the pushup-takeoff (Fig. 1) and the presence of a giant eyeball in the front of the skull (Bennett 2007, Fig. 1). That was repaired here and here (Fig. 1) several years ago. The purported scleral (eyeball) ring is in fact the maxilla in the smaller flat-head SMNS 81928 specimen (Fig. 1) incorrectly referred to the genus Anurognathus (Figs. 3a, b) by Bennett 2007 and repeated by Hone 2020. Correcting the eyeball problem resulted in a traditional dimorphodontid/ anurognathid-type skull (Fig. 1 top figures) despite the skull being flatter than tall, a morphology repeated several times in later anurognathid discoveries.

Bennett presented a unique morphology
(not shared with any other pterosaur) that was copied and embraced by Witton and Hone without question. Both PhDs should have done their own scientific research instead of trusting anyone under this simple rule: “Extraordinary claims require ordinary evidence.” Yes, ordinary evidence. Just confirm or refute Bennett’s bizarre observation with your own tracing of the specimen and compare that with other similar taxa. That’s what PhDs are paid to do. To trust unique claims like Bennett 2007 without a second examination is not scientific.

Figure 1. The SMNS 81928 anurognathid specimen.

Figure 1. The SMNS 81928 anurognathid specimen, two interpretations shown slightly larger than life size. This was the first of several ‘flathead’ anurognathids to be discovered. Let’s hope the blue one can open its wings and start flapping before the eventual face plant. And how did such a take-off configuration evolve from bipedal ancestors?

In summary, Hone 2020
reviews the history of anurognathid research and renames a specimen. Hone promotes previous mistakes (Fig. 1) as valid without support from new, confirming tracings or any tracings whatsoever. Only one taxon is reconstructed (Fig. 1). No phylogenetic analysis appears. The IVPP transitional anurognathid embryo is ignored along with several other basal anurognathids (Fig. 4). Some citations are omitted (see way below). All the above shortcomings and mistakes were resolved online here and at links therein several years ago.

From the Hone 2020 Abstract:
“The anurognathids are an enigmatic and distinctive clade of small, non‐pterodactyloid pterosaurs with an unusual combination of anatomical traits in the head, neck, wings and tail.”

No. After precise tracings and phylogenetic analysis in the large pterosaur tree (LPT, 251 taxa), anurognathids are not enigmas, not all are small, the traditional clade Pterodactyloidea is invalid because it is polyphyletic (Peters 2007, LPT) and there is no reason to trust Hone’s description of the head, neck, wings and tail given his use of M Witton’s invalid illustration (Figs. 1, 2).

Compare Hone and Witton’s published anurognathids
(Figs. 1, 2) with more precise tracings (Figs. 1, 3) of the skeletal and soft-tissue elements of the Anurognathus holotype (Figs. 3a, 3b) distinct from the smaller disc-head SMNS 81928 specimen (Figs. 1, 3b), both from Solnhofen limestones.

Figure 1. From Hone 2020, illustration by M Witton of Jeholopterus. Compare to figure 2.

Figure 2. From Hone 2020, illustration by M Witton of Anurognathus, not the holotype, but the SMNS 81928 as in figure 1.

Witton and Bennett 9007 place the eyeball over the maxilla
in the large antorbital fenestra, rather than further back in the orbit, as in all other pterosaurs, over the jugal (Fig. 3a cyan), behind the lacrimal (Fig. 3a pink).

Figure 2. Click to enlarge. DGS tracing of Anurognathus ammonia. Note the placement of the lacrimals in the skull, behind the large antorbital fenestra. That is not the orbit. The small jugal (bright light blue) also indicates the placement of the small orbit in the back half of the skull, as in all other anurognathids. Also note the disappearance of the cervicals beneath the matrix. That may be an embryo by the tail. More on that tomorrow.

Figure 3a. Click to enlarge. DGS tracing of Anurognathus ammonia. Note the placement of the lacrimals in the skull, behind the large antorbital fenestra. That is not the orbit. The small jugal (bright light blue) also indicates the placement of the small orbit in the back half of the skull, as in all other anurognathids. Also note the disappearance of the cervicals beneath the matrix. That may be an embryo by the tail. More on that tomorrow.

Figure 1. The flat-head pterosaur, a private specimen (on the left) attributed by Bennett (2007) to Anurognathus ammoni (on the right).

Figure 3b. The flat-head pterosaur, a private specimen (on the left) attributed by Bennett (2007) to Anurognathus ammoni (on the right). Pedal digit 5 does not frame a membrane. Rotodactylus and other bipedal Jurassic pterosaur  tracks show how it impresses.

Hone 2020 abstract continues:
“They [anurognathids] are known from very limited remains and few have been described in detail, and as a result, much of their biology remains uncertain.

If pterosaur expert, Dr. Hone, doesn’t want to go to the effort, and wants to ignore workers who have gone to the effort years earlier (Figs. 1-4), before too long Dr. Hone will not be known as the expert he trained to be and thinks he is.

“This is despite their importance as potentially one of the earliest branches of pterosaur evolution or even lying close to the origins of pterodactyloids.

Well, which is it? Basal or transitional? A bit of effort, like creating a cladogram, would have resolved this issue. Hone has a PhD in paleontology. He should not leave things vague and unanswered. This is his passion and his job and he is not doing his job or following his passion.

“This review covers the taxonomy and palaeoecology of the anurognathids, which remain an interesting branch of pterosaurian evolution.”

Hone defined the Anurognathidae,
“as all taxa more closely related to Anurognathus than Dimorphodon, Pterodactylus or Scaphognathus.” That would include all of the taxa (and a few more recent ones) shown in figure 4. Many of these did not appear in the Hone 2020 review, which was intended to be comprehensive.

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

Figure 4. Click to enlarge. Anurognathids to scale. The adult of the IVPP embryo is 8x the size of the embryo, as in all other tested adult/embryo pairings.

See below for comments
on Hone’s self-published publicity statement, which summarizes his paper and arrived a few days before the PDF became available.


References
Bennett SC 2007. A second specimen of the pterosaur Anurognathus ammoni. Paläontologische Zeitschrift 81(4):376-398.
Hone DWE 2020. A review of the taxonomy and palaeoecology of the Anurognathidae (Reptilia, Pterosauria). Acta Geologica Sinica (English edition)
https://onlinelibrary.wiley.com/doi/epdf/10.1111/1755-6724.14585?saml_referrer

From DWE Hone’s publication announcement:
“Revising the frog-mouthed pterosaurs: the anurognathids”

Oops. This paper is not a revision. Hone 2020 is titled, “A review of the taxonomy and palaeoecology of the Anurognathidae”. A revision would revise present thinking. Hone himself notes he makes no attempt to do this. Let’s imagine Hone was thinking of the word ‘reviewing’ when he wrote the PR piece, but inserted the more exciting word ‘revising’ by accident.

“The anurognathids are a wonderful group of small non-pterodactyloid pterosaurs known from Europe and various parts of Asia that are perhaps the most distinctive of the early pterosaur groups and probably the latest survivors.

According to the large pterosaur tree (LPT) and simple logic, several clades of Middle and Late Jurassic pterosaurs gave rise to four pterodactyloid-grade clades, some of which extended to the last day of the Cretaceous. You don’t get Cretaceous pterosaurs without Jurassic and Triassic ancestors. Anurognathids also invaded North and South America, according to phylogenetic analysis and footprints.

“They had bizarrely short and broad skulls made of tiny spars of bone and with few teeth and remarkably short tails for non-pterodactyloids. They were mostly small and are interpreted as having been hawking for insect prey on the wing. There are few specimens (even with the recent discoveries) that are hard to tell apart because they are all so similar and yet almost every different specimen has been named as a new species.”

Hone puts no effort (no tracings, a single borrowed reconstruction, no original cladograms) into understanding, reconstructing, modeling, lumping and splitting the several known anurognathid specimens. As in prior studies, Hone stands back when scientific work is required. Hone’s writing is only in service and support to his traditional bias. He avoided citing several peer-reviewed studies that included other anurognathid materials (see below). Bottom line: Hone is supposed to be a scientist, not a journalist. He should be shedding new light on anurognathids, resolving the enigmas, not repeating what others have already published. That’s what journalists do.

“So they are both really unusual and not very well known and that means even if this has taken time to come to fruition, a review of them would be rather handy. And so as you might imagine, this post coincides with a new paper doing exactly that. Somewhat inevitably there’s not a huge amount to talk about here since as it’s a review, it doesn’t contain too much that’s new – the primary role is to bring things together and synthesise them so most of what is there is already known (at least to people who keep up with the pterosaur literature). Reading the review will bring you up speed if you want all the basics, but I do want to talk here about a couple of the more interesting things I have added.”

“The first one is the validity of the various taxa. It’s hardly unknown for pterosaur clades to be made up of lots of species each represented by only a single specimen but the anurognathids are pushing even that. While I can’t immediately think of any calls for synonymy of any taxa, the fact that so few specimens have been described in detail and the poor quality of the preservation of many means that the available lists of diagnoses have been pretty weak to date.

In counterpoint, detailed tracings and reconstructions have been online for every known anurognathid (Fig. 4) for several years. Hone omitted several of these taxa. A cladogram would have helped him separate in-groups from out-groups.

“They are not much better now, but I have at least revised and updated the diagnosis of every taxon. There are two consequences of this that are important. First off, all the current taxa seem valid, and moreover, some of the recently illustrated, but not yet named, specimens also look like they are distinct taxa and there’s probably several new names needed. Secondly, the second species of Dendrorhynchoides, D. mutodongensis is as distinct, if not more so, than many other anurognathid genera and as such needs to be elevated to the genus level… I erected the new genus Luopterus to house the species.

That’s a good name for a specimen needing a new generic name. Well done, Dave!

“Next up, the variation in the different species is quite odd. Anurognathids are weirdly conservative, even compared to other pterosaur groups and while the poor preservation of the specimens hasn’t helped up find distinguishing traits between them, once you sit down and really look it’s hard to find the kinds of traits that you might normally use to separate out genera and species.”

Seeking traits to separate specimens is “Pulling a Larry Martin“. Don’t do that. It leads to madness due to convergence, or, in this case, backing away from what must be done: a comprehensive phylogenetic analysis with all the anurognathid taxa and parts thereof laid out, lumped and separated.

“That said, there are some bits of variation which while commented on before are quite notable in this context (and there is more coming on this in a future paper that I’m involved in). The length of the tail is really variable and while these are as a whole short-tailed (even the longest of them is much shorter than other non-pterodactyloids) there is really quite some difference between the longest and the shortest. I don’t know what this means but it’s an area worthy of greater attention.

Unfortunately, Hone only crudely illustrates the variety found in anurognathid humerus shapes, but omits doing the same for the tails, or any other body parts, especially the skulls. If an amateur can do it (Figs. 1–4), a paid professional and a PhD should be able to do it that much better.

“Similarly, the smaller anurognathids tend to have extraordinarily large heads and the larger ones rather small ones.

This needed to be illustrated and documented. Reconstructions (see Fig. 4) do not reflect and confirm Hone’s observation.

“There could be ontogentic effects here since many of the smaller specimens are juveniles but it stands in contrast with the more general isometry of other pterosaurs, and could be linked to prey sizes or even eye size. If they are, any [sic] many people suspect, nocturnal then juveniles need huge heads to house huge eyes.”

Hone is correct with regard to pterosaur isometry, so why then does he label some pterosaurs ‘juveniles’, rather than small adults of distinct genera? The huge eyes guess is easily resolved by tracing each specimen and locating the eyes, none of which are ‘huge”, with the exceptions of Batrachognathus (Fig. 5) having the most owl-like eyes and most binocular. Even so, those eyes remain in the back half of the skull, as in ALL other pterosaurs.

Dorsal and lateral views of three anurognathid pterosaurs.

Figure 5. Dorsal and lateral views of three anurognathid pterosaurs. From left to right, Dendrorhynchoides, Batrachognathus and Jeholopterus, all crushed dorsoventrally, due to the skull’s greater width.

Hone continues
“Finally, there is the issue of the ‘folded’ wings. While some disarticulation can occur in decaying pterosaurs unless the specimen has disintegrated the various bones of the wing finger stay together. Presumably they are held together by numerous strong ligaments or they would not be able to hold up the forces of flight. It’s a very derived condition since of course all other archosaurs (indeed tetrapods generally) can flex their fingers.

Pterosaurs are not archosaurs. This is yet another myth Hone promotes without citing competing studies. He tried to do so once, but choked on the attempt, kowtowing to the agenda of his professor and mentor, Mike Benton. Hone has not been under the influence of Benton for over a decade, so he should show a little independence now. As a PhD pterosaur expert, knowing what a pterosaur is… that is his job and he is not doing his job. More on the wing issue below.

Anurognathids however, despite having some exquisitely preserved specimens, and nearly all of them being basically articulated, show the joints of the wing finger being flexed. This suggests that they are doing something really rather different with their wings, when flying or even when on the ground.

Not at all. The small size of most anurognathids means the wing finger did not need to be as robust as in the larger clades. That alone could account for the flexion seen in many anurognathid wing phalanges (Figs. 4, 6). There’s also taphonomy. And speaking of wings, no pterosaur fossil shows the wing membrane extending down the thigh to the ankle, as shown in the Witton illustrations (Figs. 1, 2).

Tracing of Jeholopterus using DGS.

Figure 6. Click to enlarge. Tracing of Jeholopterus using DGS. Dorsal view of Jeholopterus based on the tracing. Lower left images include an unidentified pair of semi-circles too large to be embryo upper temporal fenestrae (that was the first guess). The tail is not particularly short when stretched to its full length, despite the reduced length of the individual caudals. The red ellipse represents a hypothetical egg shape. The abdomen was not so wide. The ribs would have had a ventral component and direction, which they do not have here. Note the right angle femoral head, ideal for parasagittal locomotion, like a dinosaur.

“One thing to note is that this is also seen in one other set of pterosaur specimens – embryos. That implies that either anurognathids have inherited this trait from their ancestors (if they are, as some suggest, the first branching group of pterosaurs) or have secondarily acquired what is essentially a paedomorphic trait of wing flexion.”

If Hone had produced a valid cladogram, like the LPT, he would have been able to find a solution to his own problem. See figure 4 for a quick graphic review.

“I’ll leave it there for now. There’s plenty more in the paper that you can read and there is obviously more research to come (indeed I’m working on another anurognathid paper that’s come about in part through this work) so don’t want to go over this in detail when it’s already a review. Hopefully this does sort out a few issues and pave the way for a better understanding of these most interesting of pterosaurs.”

In counterpoint, and allowing for a little verbal showmanship on Hone’s part (e.g. using “revising” instead of “reviewing” in his PR ), all pterosaurs should be equally interesting because taxon omission by PhDs is a traditional sin. Granted, Hone is infatuated with anurognathids, like the proud father of any new paper generally should be. Unfortunately, because this paper is already in print, it is now too late to give it the care and attention it should have had when still in his mind and on his monitor.

David Hone is still a young man.
I hope that someday he will see the light, crawl out of Benton’s shadow, do the work he is paid to do, stop hiding behind taxon and citation omission, and ultimately become the pterosaur expert he trained to be.


Papers and abstracts omitted by Hone 2020
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 2002. A New Model for the Evolution of the Pterosaur Wing – with a twist. – Historical Biology 15: 277–301.
Peters D 2003. The Chinese vampire and other overlooked pterosaur ptreasures. ournal of Vertebrate Paleontology, 23(3):87.
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.
Peters D 2010. In defence of parallel interphalangeal lines.
Historical Biology iFirst article, 2010, 1–6 DOI: 10.1080/08912961003663500
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification
Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605

See a pattern here?
Kids, if you want to get cited, get your PhD and go with the traditional bias and flow. Be willing to ignore competing citations if they come from outsiders who are willing to do the work and go the extra mile without getting paid [heavy on the sarcasm here, for those who are thinking about quote-mining this paragraph].

Development and evolution of the notarium in Pterosauria: notes and review

Aires et al. 2020
plotted the evolution of the notarium (= fused dorsal vertebrae anchoring the scapulae; Fig. 1) in pterosaurs. “The notarium is the structure formed by fusion of the dorsal vertebrae which occurred independently in pterosaurs and birds. This ankylosis usually involves two to six elements and in many cases, also includes the last cervical vertebra.

I have not seen incorporation of the most proximal of eight cervical vertebra into the notarium of pterosaurs yet. The authors note, “Vertebral fusion can be observed among contiguous centra, neural spines, and transverse processes, sometimes forming a ventral plate.” Not mentioned by the authors, dorsal vertebral fusion can occur independent of scapulocoracoid fusion and/or sacral fusion.

“Fusion can occur in different degrees, uniting the vertebral centra, the neural spines, the transverse processes, the ventral processes, or a combination of these sites. A detailed assessment of the fusion process of pterosaur dorsal vertebrae is still lacking. Here we identify the fusion sequence of pterosaur notarial elements, demonstrating the order of ossification in vertebral bodies and neural spines based on fossils and extant birds. In both Pterosauria and Aves, the notarium generally develops in a antero‐posterior direction, but the actual order of each fusion locus may present slight variations. Based on our data, we were able to identify seven developmental stages in the notarium formation, with broad implications for the prediction of ontogenetic stages for the Pterosauria.”

These ontogenetic implications do not pan out. They are based on an incorrect archosaur model of ontogeny, not the lepidosaur model of pterosaur ontogeny.

“In addition, we report the occurrence of a notarium in Ardeadactylus longicollum (Kimmeridgian, Southern Germany), the oldest occurrence of this structure in pterosaurs.”

That notarium was first published here (Fig. 1) in 2013 when that specimen was known as Pterodactylus longicollum, a taxon that nests in the Pterodactylidae far from the holotype of Ardeodactylus (Fig. 2) nesting with pre-azhdarchids.

Figure 1. Cladogram from Aires et al. 2020 suffering greatly from taxon exclusion to such an extent that unrelated pterosaurs are nested with one another.

Figure 1. Cladogram from Aires et al. 2020 suffering greatly from taxon exclusion to such an extent that unrelated pterosaurs are nested with one another. Black dot = notarium. White dot = no notarium. N = origin of notarium?

A collection of notarium data is good to have.
However the Aires et al. cladogram (21 taxa, Fig. 1) suffers greatly from taxon exclusion when compared to the large pterosaur tree (LPT, 251 taxa, Fig. 2 click to enlarge) where taxa with a notarium are highlighted in yellow.

As the outgroup Aires et al. mistakenly used 
a bipedal crocodylomorph with tiny fingers, Scleromochlus when the validated outgroups have been known for 20 years. This is an ongoing embarrassment for traditional pterosaur workers blindly supporting academic textbooks and lecturers.

Problems in the above illustration
(Fig. 1) begin with a sharp snouted Pteranodon nested with toothy, broad-snouted ornithocheirids (Scaphognathus descendants), rather than the sharp-snouted taxa with crests like tapejarids and dsungaripterids (Germanodactylus descendants). Excluding pertinent taxa in pterosaur cladograms is another ongoing embarrassment, where PhDs have let amateurs take the lead by simply adding taxa irregardless of bias, tradition and academic pressure.

Figure x. LPT. Taxa with notarium in yellow.

Figure 2. LPT. Taxa with notarium in yellow. Click to enlarge.

Oddly the Aires et al. conclusions do not place
a minimum size on notarium development. Principally large pterosaurs (and their juveniles) fuse vertebral spines (Figs. 1, 2) in the LRT.

Germanodactylus
Aires include a specimen of duck-sized  Germanodactylus (BSP 1892) among taxa with a notarium, citing the observations of others as evidence. The dorsal vertebrae in that specimen are exposed ventrally. No sister taxa in the LPT have a notarium, making that second-hand observation questionable for several reasons.

Nyctosaurus
The same holds true for the only Nyctosaurus listed (FHSM VP 2148) by Aires et al. 2020. The potential notarium is buried in the matrix, ventral surface exposed, each centrum distinct from the others. No other Nyctosaurus specimens have a notarium, including the UNSM 93000 specimen, which is exposed dorsally and the vertebrae are scattered. That’s why neither is marked with a notarium in the LPT (Fig. 2).

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

Figure 1. Goose-sized Diopecephalus = P. longicollum = Ardeadactylus. Normannognathus is in the box in the lower left. Santanadactylus GIUA M 4895 at upper right. Note the unfused scapulocoracoid.

I found 16 pterosaur taxa with a notarium
out of 251 taxa in the LPT. One can add UNSM 50036, a postcranial Pteranodon of great size, which is not listed among the skull-only taxa. Several other post-cranial Pteranodon specimens (e.g FHSM VP 2062, UUPI R197) likely had a notarium given the morphology of the proximal scapulae. All are large specimens as adults. Taxa with a notarium nest in five separate clades in the LPT.

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

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

By contrast
some equally large pterosaurs (e.g. Arthurdactylus, Anhanguera) do not have a distinct notarium bar (fused and ossified parasagittal ligaments), but are reported to fuse the complete dorsal series. In the former, the sacrum was likewise fused to the dorsal series. In the later, 3 cervicals were fused to the dorsal series. Neither had a notarial bar (fused and ossified parasagittal ligaments).

Figure 2. FHSM 17956 compared to Ptweety. They are virtually identical, though Ptweety looks like a juvenile of a more robust variety of Pteranodon, thus a younger specimen because adults would be larger.

Figure 3. FHSM 17956 compared to Ptweety. They are virtually identical, though Ptweety looks like a juvenile of a more robust variety of Pteranodon, thus a younger specimen because adults would be larger.

Some inappropriate name changes are present in Aires et al.
Coloborhynchus spielbergi has been renamed Anhanguera spielbergi. Coloborhynchus robustus has been renamed Anhanguera robustus. Not sure why Aires et al. are promoting  this inappropriate lumping.

Figure 1. The new small Pteranodon wing, FHSM 17956, compared to Ptweety and the adult NMC41-358 specimen.

Figure 4. The new small Pteranodon wing, FHSM 17956, compared to Ptweety and the adult NMC41-358 specimen.

The juvenile Pteranodon
unnumbered and privately owned ‘Ptweety‘ also has a notarium, as expected. Pterosaurs, like all tritosaur lepidosaurs, developed isormetrically during ontogeny with phylogenetic ossification patterns traditionally misunderstood by pterosaur workers and their professors.

Figure 2. Gallus, the chicken, nests as a sister to the Early Cretaceous, Eogranivora, also a seed-eater.

Figure 5. Gallus, the chicken, fuses the entire backbone and sacrum, but note the scapula is not involved.

Bottom line
Colleagues, let’s all add taxa to your in-groups and out-groups so conclusions will not be undermined by an improper phylogenetic context. Let’s not cite the questionable observations of others unless confirmable by phylogenetic bracketing. There have been so many false positives published by pterosaur workers unchecked by other pterosaur referees and professors that interested amateurs are able to stand up and point the finger noting errors and omissions. Let’s fix this, together.


References
Aires AS, Reichert LM, Müller RT, Pinheiro FL and Andrade MB 2020. Development and evolution of the notarium in Pterosauria. Jounal of Anatomy. https://doi.org/10.1111/joa.13319

 

SDUST-V1003 is not Forfexopterus

Zhou, Wang and Zhou 2020 describe a new pterosaur specimen
based on a single articulated wing (SDUST-V1003; (Fig. 1), which they assigned to Forfexopterus (Fig. 2)… with this odd reservation: “It is only about 75% the size of the immature holotype.”

By contrast
in the large pterosaur tree (LPT, 251 taxa) the SDUST-V1003 (Fig. 1) nests with a slightly earlier and smaller Yixian Formation pre-azhdarchid pterosaur, Beipiaopterus (Fig. 3).

Figure 1. SDUST-V1003, formerly Forfexopterus, in situ and reconstructed.

Figure 1. SDUST-V1003, formerly Forfexopterus, in situ and reconstructed. Note the slender free fingers and giant unguals. The radius was taphonomically displaced. A tiny wing finger claw is present. Metacarpus 4 was split and splintered. perhaps during axial wing rotation during taphonomy.

Zhou, Wang and Zhou 2020 considered the following pterosaurs
ctenochasmatids. Most are not when you add more taxa, as in the LPT.

  1. EosipterusElanodactylus – Germanodactylidae
  2. Feilongus, Pterofiltrus, MoganopterusCycnorhamphidae
  3. Beipiaopterus, Forfexopterus  pre-Azhdarchidae
  4. Gegepterus, Gladocephaloideus – Ctenochasmatidae
  5. Cathayopterusnot tested yet
Figure 2. Forfexopterus compared to sisters Huanhepterus and Ardeadactylus and the BYU specimen of Mesadactylus.

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

The SDUST pterosaur is known from
a slab containing a complete wing (lacking manual 2.2, 2.3, 3.2, 3.3 and 3.4; Fig. 1) with somewhat different proportions than the holoytpe Forfexopterus (Fig 2), The differences turn out to be enough to separate the two in the LPT. The referred specimen (SDUST V1003) nests two nodes apart from Forfexopterus, so the two cannot be congeneric.

Figure 3. Beipiaopterus to scale with the SDUST pterosaur. Beipiaopterus wing enlarged to match the SDUST pterosaur.

Figure 3. Beipiaopterus to scale with the SDUST pterosaur. Beipiaopterus wing enlarged to match the SDUST pterosaur. Note how relatively tiny the free fingers are in these taxa.

From the Zhou, Wang and Zhou abstract:
“In the Jehol Biota, the filter-feeding ctenochasmatid pterosaurs flourished with a high biodiversity. Here, we report a new wing skeleton of the ctenochasmatid Forfexopterus from the Early Cretaceous Jiufotang Formation in Jianchang, western Liaoning, China. The specimen exhibits the sole autapomorphy, the first wing phalanx shorter than the second and longer than the third.”

Other pterosaurs also share this trait. As long-time readers will readily realize, Zhou, Wang and Zhou were “Pulling a Larry Martin” by relying on this single trait, or a dozen traits.

“Interestingly, it exhibits a skeletal maturity with co-ossified elements, but it is only about 75% the size of the immature holotype.”

Here the authors reveal they were misinformed on the subject of pterosaur  phylogeny and ontogeny Pterosaurs are tritosaur lepidosaurs with isometric growth patterns and phylogenetic (not ontogenetic) ossification patterns. Thus for good reason, pterosaurs don’t follow archosaur growth and ossification patterns.

“This discrepancy reveals developmental variation of Forfexopterus, but its relationship with sexual dimorphism needs to be certain by more available material.”

Pterosaurs have not yet shown sexual variation in their skeletons. Not yet.

The holotype Forfexopterus jeholensis
(Jiang et al. 2016; Early Cretaceous; Fig. 2) was originally considered an Archaeopterodactyloid. There is no such valid clade in the LPT. Here Forfexopterus nests with Ardeadactylus and Huanhepterus (Fig. 2) and other tall, slender pterosaurs basal to Azhdarchidae.


References
Jiang S, Cheng X, Ma Y and Wang X 2016. A new archaeopterodactyloid pterosaur from the Jiufotang Formation of western Liaoning, China, with a comparison of sterna in Pterodactylomorpha. Journal of Vertebrate Palaeontology: e1212058.
Zhou C-F, Wang J and Zhou Z 2020. A new wing skeleton of Forfexopterus (Pterosauria: Ctenochasmatidae) from the Early Cretaceous Jehol Biota reveals a developmental variation. Fossil Record 23:191–196,

wiki/Huanhepterus
wiki/Forfexopterus
wiki/Ardeadactylus
wiki/Beipiaopterus