Aardonyx (basal sauropodomorph) enters the LRT

Aardonyx celestae 
(Yates et al. 2010; Fig. 1) was originally considered a basal sauropodomodph dinosaur, because it is one.

Figure 1. Aardonyx from Yates et al. 20109. Colors added.

In the large reptile tree (LRT, 1760+ taxa; subset Fig. 2) Early Jurassic Aardonyx nests with the Late Jurassic prosauropod, Saturnalia, a taxon not mentioned in the Yates et al. paper. Aardonyx is larger, more robust and has shorter feet, as in sauropods, making it a sauropod mimic.. so, not in the lineage of sauropods. That should be relatively uncontroversial.

Figure 2. Subset of the LRT focusing on basal phytodinosauria. Aardonyx nests with Saturnalia here.

 

References
Yates AM, Bonnan MF, Neveling J, Chinsamy A and Blackbeard MG 2010. A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism. Proceedings of the Royal Society B. 277(1682): 787–794.

wiki/Saturnalia
wiki/Aardonyx

SVP abstracts 10: Scottish Middle Jurassic pterosaur, back again this year

Updated February 24, 2022
with the publication and naming of this specimen. Details here.

Revised November 4, 2020
with the news that two Skye pterosaurs have been presented in SVP abstracts, not the one I assumed. Neither has been published yet, so I don’t know if the accompanying illustrations represent one or the other.

This is the second time
the wonderful Skye, Scotland pterosaur has entered the SVP abstracts. The first was in 2019, covered here. Evidently, this specimen is still unnamed and unnumbered, so I wondered, what progress does the new set of authors bring to this specimen this year?

From the Jagielska et al. 2020 abstract:
“An incomplete fossil record limits understanding of pterosaurian macroevolution during the Middle Jurassic, a period associated with diversification of many major pterosaur clades.”

By contrast, the fossil record in the large pterosaur tree (LPT, 251 taxa) has no large gaps during the Middle Jurassic (Fig. 2) or otherwise. The fossil record is more complete than the authors realize, evidently due to taxon exclusion.

“The European Middle Jurassic pterosaurian record, until now, has consisted of numerous non-taxon specific specimens and included a single named genus, based on a partially preserved dentary.”

Are we forgetting all the many Dorygnathus specimens (Fig. 2)? Several are transitional to higher pterodactyloid-grade taxa, either directly (ctenochasmatids and azhdarchids) or indirectly through Scaphognathus (the rest of them; Peters 2007).

Figure 2. Click to enlarge. The descendants of Sordes in the Dorygnathus clade and their two clades of pterodactyloid-grade descendants.

Continuing from the Jagielska et al. 2020 abstract:
“Here we describe a new three-dimensionally preserved partial skeleton from the Bathonian Lealt Shale Formation of Skye, Scotland, that helps fill the Middle Jurassic pterosaur gap. It is the most complete fossil from the Jurassic sequence of the Scottish Hebrides, which commonly yields ichnofossils but only fragmentary archosaur remains, and the first nearly complete Middle Jurassic pterosaur from outside of China. The new pterosaur is mostly articulated and includes the skull (which retains delicate palatal, hyoid, and neurocranial elements), complete cervical and caudal vertebral series, fully preserved paired forelimbs with partially preserved wing phalanges, a disarticulated dorsal vertebral series and ribcage, and a poorly preserved sacral, pelvis and hindlimb region. It is the largest non-pterodactyloid on record, with an estimated 2 m wide wingspan.”

We also heard this in 2019. Since the authors have changed, perhaps no one told Jagielska et al. that this specimen was featured in an SVP abstract a year ago.

“The specimen represents a new genus and species diagnosed by several autapomorphies, including slender, curved humeral shaft; large teardrop-shaped lower temporal fenestra; a novel “jugo-lacrimal” fossa, and unique palatal arrangement with trident-shaped anterior vomer.”

As Larry Martin was quick to note, most autapomorphies can be found in other tetrapod taxa by convergence. So first, run the analysis. Then start describing some interesting traits.

“We conducted a phylogenetic analysis by combining several published datasets, which placed the new Scottish pterosaur within the paraphyletic array of non-monofenestratans commonly called the Rhamphorhynchinae, where it shares cranial similarities to the similarly-aged Chinese Angustinaripterus longicephalus.”

Sometimes more data nests taxa elsewhere, but their ‘several published datasets’ don’t include the LPT (subset Fig. 3). Borrowing other datasets usually absolves authors from mistakes made by prior authors, especially taxon exclusion issues. Colleagues, students: create your own datasets. Create your own reconstructions. By the way, in 2019 the earlier set of authors nested the Skye pterosaur with Darwinopterus and Wukongopterus, far from Angustinaripterus. The LRT nests the Skye pterosaur basal to the clade of wukongopterids (Fig. 3).

“We imaged the skull using microCT, which reveals a brain endocast with a large cerebellum and floccular region wrapped by thin, curved semi-circular canals of the inner ear, similar to closely related Rhamphorhynchus muensteri.”

The 2019 abstract likewise mentioned µCT scans. None of the above taxa are closely related to R. muensteri.

Continuing from the Jagielska et al. 2020 abstract:
“Along with the highly diverse but fragmentary Tayton Limestone Formation assemblage of England, the new specimen challenges the long-considered notion that the European Middle Jurassic was a time of low pterosaur diversity and anatomical disparity.”

One more specimen that we knew about last year will not challenge a ‘long considered notion’ that was never a notion to begin with. Hate to be snippy here, but hyperbole is not appropriate in science simply to elevate a notion or a cladogram, especially if it lacks dozens of pertinent taxa.

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References
Jagielska N et al. (9 co-authors) 2020. An exceptionally well preserved pterosaur from the Middle Jurassic of Scotland. SVP abstracts 2020.
Martin-Silverstone E, Unwin DM and Barrett PM  2019. A new, three-dimensionally preserved monofenestratan pterosaur form the Middle Jurassic of Scotland and the complex evolutionary history of the scapulo-vertebrael articulation. SVP abstracts 2019. Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.

https://pterosaurheresies.wordpress.com/2019/11/01/svp-abstracts-the-skye-pterosaur/

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

Updated January 17, 2022
with a new nesting for Hongshanopterus with another Early Cretaceous Hamipterus both derived from Darwinopterus.

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

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

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

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

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

Figure x. Revised palate of Hongshanopterus palate.

By contrast
the large pterosaur tree (LPT, 251 taxa then, 261 taxa in 2022) nested Hongshanopterus with Hamipterus and Darwinopterus, far from any istiodactylids. It takes 5 extra steps to force fit Hongshanopterus in the base of the Istiodactylidae (and that’s using just the few characters visible in Hongshanopterus).

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

Figure xx. Hongshanopterus palate compared to Hamipterus and Darwinopterus. Added June 16, 2022.

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

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

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

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

wiki/Hongshanopterus
wiki/Wukongopteridae

New tiny ‘Ctenochasma’ at the Field: Lauer Foundation Collection

The Lauer Foundation for Paleontology provided
this tiny crushed Ctenochasma? elegans? Fig. 1) to the Field Museum, Chicago, USA. The foundation number is: #LF 2296. It enters the large pterosaur tree (LPT, 250 taxa; Fig. 2) distinct from all other tested pterosaurs.

Figure 1. A tiny Ctenochasama micronyx undergoes DGS here. Every bone is present, but no soft tissue this time. Note the tiny claws on all digits along with the slightly spoon-shaped rostrum and needle-like teeth.

Tiny, yes, but not a juvenile.
As we learned earlier, pterosaur hatchlings have adult proportions. Pterodaustro presents the phylogenetically closest example, in this case. Phylogenetic miniaturization is how we get tiny pterosaurs. And tiny pterosaurs are transitional taxa. That’s how we get derived pterosaurs. Note the tiny Ctenochasma? elegans specimens all nest together (Fig. 2). These tiny pterosaurs are adults that would have produced 8x smaller hatchlings, often about the size of house flies. and therefore unable to fly without risking desiccation due to a high surface-to-volume ratio. In other words, hatchlings of tiny pterosaurs could have flown, but needed to keep their wings folded. So they walked, picking up small prey in damp leaf litter. And that’s why so many pterosaur tracks are from pterodactyloid-grade pterosaurs, many of which continued to feet quadrupedally as they grew into phylogenetically larger genera.

Figure 2. Subset of the LRT focusing on ctenochasmatids and kin.

Earlier we looked at the Fossilienatlas.de specimen
assigned to Ctenochasma elegans #204 (Fig. 4), which provides a similar morphology in reconstruction. No scale bars were provided with the Lauer Collection specimen, but the size can’t be too far off from this.

Figure 3. Click to enlarge. Private pterosaur #2042 together with St/Ei1, which nests at the base of the ctenochasmatidade, close to Angustinaripterus.

References
https://www.fieldmuseum.org/blog/meet-pterosaur-flock
https://www.lauerfoundationpse.org/about

New Rhamphorhynchus at the Field: Lauer Foundation Collection

The Lauer Foundation for Paleontology provided
this deep cut Rhamphorhynchus (Fig. 1) to the Field Museum, Chicago, USA. The foundation number is: #LF 1182. Photoshop helps get rid of the surface and deep cuts to see the bones without those distractions.

Figure 1. Another deep cut Solnhofen fossil from the Lauer Collection at the Field Museum, Rhamphorhynchus.

Due to its generic look,
the Lauer Foundation specimen enters the large pterosaur tree (LPT, 250 taxa) somewhere in the middle of this genus, distinct from all others, between the ROM specimen (first row, far right, Fig. 2) and the Imhof specimen (second row, far left, Fig. 2).

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

This wonderful and complete specimen
nests in the middle of the tested Rhamphorhynchus (Fig. 2) specimens (Fig. 3), outside the clade of the largest specimens (including the large and only juvenile, the Vienna specimen row 2, second from right)..

Figure 3. Subset of the LPT focusing on Rhamphorhynchus.

References
https://www.fieldmuseum.org/blog/meet-pterosaur-flock
https://www.lauerfoundationpse.org/about

New Pterodactylus at the Field: Lauer Foundation Collection

The Lauer Foundation for Paleontology provided
this deep cut Pterodactylus to the Field Museum, Chicago, USA. The foundation number is: #LF 513. It enters the large pterosaur tree (LPT, 250 taxa) distinct from all other tested pterosaurs.

Figure 1. Pterodactylus at the Field Museum from the Lauer Collection

Basically it’s your run-of-the-mill Pterodactylus,
nesting pretty much in the middle of a clade that has divided into several subclades (Fig. 2) each with several members. Now there’s another PhD thesis in the making! Who wants to lump and split?

Figure 2. Subset of the LRT focusing on Pterodactylids and Pterodactylus.

It’s worth noting the ribcage,
the one part of any pterosaur that gets the least attention. In many pterosaurs the ribcage forms the torso into a cylinder or a Releaux triangle (triangle with curved sides), but here, as in several anurognathids and Sharovipteryx, the ribcage has a flatter appearance, more elliptical in dorsal view, more like a flying saucer.

Figure 3. Sharovipteryx reconstructed. Note the flattened torso.

References
https://www.fieldmuseum.org/blog/meet-pterosaur-flock

https://www.lauerfoundationpse.org/about

‘Rhamphorhynchus biter’, Aspidorhynchus, enters the LRT

On the subject of the Late Jurassic pterosaur biter, Aspidorhynchus,
Wikipedia reports, “Although it would have looked superficially similar to the present day gar, its closest living relative is actually the bowfin.” 

Figure 1. Aspidorhynchus overall. To the left, off screen, is the pterosaur, Rhamphorhynchus.

By contrast, 
in the large reptile tree (LRT, 1698+ taxa) Aspidorhynchus (Figs. 1, 2) nests with another swordfish-mimic from the Late Cretaceous Niobrara Sea, Protosphyraena (Fig. 3).

Figure 2. The face of the Wyoming Dinosaur Center CSG 255 specimen of Aspidorhynchus + Rhamphorhynchus with facial bones identified using DGS. The uppermost jugal plate (cyan) may be a postorbital based on phylogenetic bracketing,  but its disconnection from the circumorbital postorbital suggests a jugal replacement in that space.

Among living taxa,
the closest relative is the arowana, Osteoglossum, an Amazon River surface feeder. This may be one clue as to how several Aspidorhynchus specimens met several Rhamphorhynchus specimens, to their mutual doom.

Figure 3. Skull of Protosphyraena. Colors added to march tetrapod homologies and updated here from previous guesstimates. Comapare to figures 3 and 4.

If I’m not mistaken, 
this is a novel hypothesis of interrelationships based on taxon inclusion. If there is an earlier citation, let me know so I can promote it here. Googling the two genera just seems to bring up lists of genera without making a connection between the two.

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References
Agassiz L 1843. Recherches sur les poissons fossiles: 5 vols, with atlas (Neuchâtel).
Blainville HMD de 1818. Poissons fossiles. Nouveau Dictionnaire d’Histoire Naturelle 27: 310–395.
Frey E and Tischlinger H 2012. The Late Jurassic pterosaur Rhamphorhynchus, a frequent victim of the ganoid fish Aspidorhynchus?. PLoS ONE. 7 (3): e31945. Bibcode:2012PLoSO…7E1945F. doi:10.1371/journal.pone.0031945.

wiki/Aspidorhynchus

Early Jurassic Ohmdenia and Strongylosteus enter the LRT

Updated December 17, 2020 and November 2, 2022
with a new tracing of Strongylosteus that reveals it was nearly identical to Chondrosteus.

We’re talking about large Early Jurassic bony fish
with small teeth (or no teeth) today, one mistakenly nested by prior workers due to taxon exclusion.

Friedman 2011
reexamined Ohmdenia, who mistakenly reported, “the enigmatic actinopterygian Ohmdenia, from the Lower Jurassic (Toarcian) Posidonia Shale of Germany (Hauff 1953), is the immediate sister group of edentulous †pachycormiforms.”

Figure 1. From bottom to top: Ohmdenia in situ, as reconstructed by Friedman 2011, as traced by Friedman 2011 (colors added) and as reconstructed here. Note the bundling of rays to produce a pectoral fin spine here.

By contrast,
with a more accurate reconstruction and by including a wider gamut of taxa, the large reptile tree (LRT, 1685+ taxa (then, 1779 taxa now), subset Fig. 9) nests long-jawed Ohmdenia with the extant long-jawed arowana, Osteoglossum, which is not a suspension feeder (contra Friedman 2011), but an opportunistic freshwater predator and a facultative air-breather.

FIgure 2. Osteoglossum skull with colors added to identify bones.

Osteoglossum formosum (Cuvier 1829; up to 2m in length) is the extant arowana or bonytongue. This taxon is among the most primitive of ray fin fish. The manus rays are robust. Note the long dorsal area. The pelvic fins are reduced to strands. Fossils extend back to the Late Jurassic.

Figure 3. The arowana, an Amazon River predator, nests with Late Jurassic Dapedium in the LRT.

The other large fish entering the LRT might be a suspension feeder
or just a predator with a large mouth lacking teeth.

New figure of Strongylosteus in lateral view.

Strongylosteus hindernburgi (originally Chondrosteus hindenburgi Pompeckj 1914; Hauff 1921; Henning 1925; Early Toarcian, Early Jurassic; 3-4.5m) is traditionally considered “related to modern sturgeons, but with a different kind of mouth.” Here Strongylosteus is little different from Chondrosteus. Strongylosteus was a giant open predator cruising opens waters with a wide mouth, similar to a whale shark (Rhincodon) by homolog.

How closely is Pachycormus related to these two?
Pachycormus (Fig. 8) is just a few nodes away from Ohmdenia, in the stem bony fish portion of the LRT (Fig. 9). That’s why these phylogenetic errors popped up. More closely related taxa were omitted and reconstructions were drawn without the use of DGS.

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References
Cope ED 1873. On two new species of Saurodontidae. Proceedings of the Academy of Natural Sciences of Philadelphia 25:337-339.
Cuvier GCLD 1829. Le Règne Animal distribué d’apres son organisation, pour servir de base a l’histoire naturelle des animaux et d’introduction a l’anatomie comparée. Avec figures dessinées d’après nature. Nouvelle édition, revue et augmentée. Tome V. Suite et fin des Insectes. Par M. Latreille. Déterville & Crochard, Paris, i-xxiv + 556pp.
Friedman M 2011, 2012. Parallel evolutionary trajectories underlie the origin of giant suspension-feeding whales and bony fishes. Proceedings of the Royal Society B 279, 944–951. doi:10.1098/rspb.2011.1381
Friedman M, Shimada K, Martin LD, Everhart MJ, Liston JJ, Maltese A and Triebold M 2010. 100-million-year dynasty of giant planktivorous bony fishes in the Mesozoic seas. Science 327(5968):990-993.
Hauff B 1921.Untersuchung der Fossilfundstätten von Holzmaden im Posidonienschiefer des oberen Lias Württembergs. Palaeontographica. 1921;64(1–3):1–42.
Hauff B 1953. Ohmdenia multidentata nov. gen. et nov. sp. Ein neuer grober Fischfund aus den Posidonienschiefern des Lias e von Ohmden/Holzmaden in Wü rttemburg. Neues Jahrb. Geol. P.-A. 97, 39–50.
Hennig E 1925. Chondrosteus Hindenburgi Pompeckj 1914.—Ein «Stör» des württembergischen Ölschiefers (Lias\epsilon). Palaeontographica (1846-1933), 115-134.
Linneaus C von 1766. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio duodecima, reformata. pp. 1–532. Holmiæ. (Salvius)

wiki/Bonnerichthys
wiki/Ohmdenia
wiki/Strongylosteus
wiki/Pachycormiformes

Taxonomic problems? Go back to the holotype.

Sometimes taxa are mislabeled.
Such is the case with Pholidophorus? radians (Figs. 1–3), a ‘herring-like’ Jurassic (Solnhofen Fm.) fish with ganoid scales, tiny fins and a large forked tail. This specimen (Fig. 1) was identified as Pholidophorus in The Rise of Fishes (Long 1995) and at the Wikipedia entry for Pholidophorus.

Figure 1. Pholidophorus in situ and two skulls attributed to this genus from Long 1995. Neither diagram matches this specimen, despite overall similarities.

The images in the diagrams above
(Fig. 1) are indeed variations on Pholidophorus (Fig. 4). However, the specimens in the photographs (Figs. 1–3) nest with Elops, the ladyfish (or tenpounder) in the large reptile tree (LRT, 1668+ taxa) on the other branch of bony fish.

Figure 2. Another specimen attributed to Pholidophorus? radians

Figure 3. DGS tracing of Pholidophorus? radians along with a reconstruction moving the crushed bones to their invivo positions.

Yesterday
I found the Pholidophorus latiusculus holotype in the literature (Arratia 2013; Late Triassic; Fig. 4). The LRT recovered it apart from the Solnhofen (Late Jurassic) specimen identified as Pholidophorus in Long 1995 and Wikipedia.

The Late Triassic holotype of Pholidophorus
nests with Osteoglossum, the extant arrowana of South America and spiny-finned Bonnerichthys, from the Niobrara Sea of the Cretaceous. All likely had their genesis in the Late Silurian based on their close-to-the-base phylogenetic node.

Figure 4. Pholidophorus holotype from Arratia 2013, overlay drawing from Agassiz 1832.

It is easy to see how later specimens
were allied with the holotype, but this turns out to be yet another case of convergence. A wide gamut phylogenetic analysis that minimizes taxon exclusion minimizes phylogenetic errors like this one. Earlier I made the mistake of combining the data from the diagram (Fig. 1) and the photo (Fig. 2) creating a chimaera. Best to just find the holotype and work from that.

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References
Agassiz L 1832. Untersuchungen über die fossilen Fische der Lias-Formation. Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde, 3, 139–149.
Arratia G 2013. Morphology, taxonomy, and phylogeny of Triassic pholidophorid fishes (Acinopterygii, Teleostei). Journal of Vertebrate Paleontology 33:sup1:1–138.
Sallan LC 2012. Tetrapod-like axial regionalization in an early ray-finned fish. Proceedings of the Royal Society B 279:3264–3271.

wiki/Pholidophorus

A Jurassic squid choking hazard for Rhamphorhynchus

Hoffmann et al. 2020 reported in no uncertain terms,
“Pterosaurs ate soft-bodied cephalopods (Coleoidea).”

Immediately after, Hoffmann et al. dialed it back a bit,
when they wrote, “Here, we report the first evidence of a failed predation attempt
by a pterosaur on a soft-bodied coleoid cephalopod.”

Based on size alone,
the squid (PIMUZ 37358) was more than a mouthful according to this ‘to scale’ diagram (Fig. 1)…at least more than a stomachful.

Ask yourself:
could a Rhamphorhynchus of that size (none were larger) eat a squid of that size? Did the pterosaur fail at predation? Or did it change its mind after biting the squid out of curiosity or boredom and losing a tooth in the process?

Figure 1. Plesioteuthis squid in situ with tooth. Reconstructions of Plesioteuthis (above) and the n81 specimen attributed to the largest known Rhamphorhynhcus, which has a matching tooth. The question is: could that pterosaur eat that squid? Or did it change its mind after biting the squid? At the very top is the hard tissue gladius of the squid to scale. That’s a hard part that would have been especially hard to swallow.

You be the judge.
Hoffmann et al. 2020 have provided the pertinent information. Above are the predator and “prey” to scale. Other Rhamphorhynchus specimens are smaller, and the tooth could have fallen from a different alveolus (a larger tooth) on a smaller specimen. Lots of variables and unknowns here. Also consider the difficulty of swallowing that long gladius, a hard part homologous with the cuttle bone in a cuttlefish.

In any case,
watch what headline you put on your paper. Here the authors went for maximum impact. If, like these authors, you have to dial it back in the second sentence of your abstract,  maybe a more conservative headline should reflect that assessment. After all, a dietary mainstay is indeed different than a curious nibble… and relative size matters.

We looked at other pterosaur choking hazards
earlier here. Pterosaurs likely swallowed their prey whole. There is no indication that they tore squids apart, creating bite-sized pieces. Likewise there is no indication that pterosaurs were able to expand their stomach to accommodate oversize prey (Fig. 1).

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References
Hoffman R, Bestwick J, Berndt G, Berndt R, Fuchs D and Klug C 2020. Pterosaurs ate soft-bodied cephalopods. http://www.nature.com/scientificreports (2020) 10:1230 | https://doi.org/10.1038/s41598-020-57731-2