SVP abstracts – 8 on Bolosaurus

Jenkins et al 2022 continue:
“This includes facultative bipedality, a secondary palate, temporal fenestration, and distinctive heterodont dentition indicative of high-fiber herbivory.“

Jenkins et al 2022 continue:
“Despite pinpointing these features on different species of bolosaurs, we know little about the anatomy of Bolosauridae. This is because most recognized specimens are limited to dentition and portions of the marginal bones.’

True. Post-crania is currently piecemeal in bolosaurs save for a string of Bolosaurus vertebra, a left pelvis and unfigured shoulder girdle (according to Broom 1913).

Jenkins et al 2022 continue:
“Furthermore (and problematically), some holotype material of Bolosaurus has never been figured or illustrated, limiting our understanding of their anatomy and the evolution of the basal branches of Parareptilia.

These are the data for Bolosaurus in the literature (Fig 3). When the authors say “some holotype material”, that’s rather vague. The authors’ tease is not fulfilled in the abstract.

Broom described the AMNH 4461 specimen:
“The skull is badly preserved, but shows in satisfactory condition the left maxilla, left prefrontal, both frontals, the left parietal, and postfrontal,and in a less satisfactory condition a number of other elements. The teeth differ from those of B. striatus in being larger and in having relatively higher crowns. In B. striatus the four largest maxillary teeth measure together 7.5 to 8 mm.: in B. major the four largest teeth measure 10 mm.”

I have not seen images of this specimen.

“To address this, we CT scanned and segmented the holotype skull of Bolosaurus major Broom 1913 (AMNH 4461). While this specimen has never been figured in previous publications, it was previously described and compared to the first named species, Bolosaurus striatus.”

See Brooms description (above).

“We confirm the presence of a secondary palate in B. major, previously only recognized in Belebey vegrandis, illustrating that this trait was present across Bolosauridae.

That statement conflicts with Watson’s illustration (Fig 3) who figured a palate on Bolosaurus 68 years ago.

B. major also demonstrates a dorsoventrally expanded coronoid that nearly spans the height of the lower jaw, indicative of large amounts of oral processing, consistent with a high-fiber diet.

Perhaps Jenkns et al meant to say, “nearly doubles the height of the lower jaw” just like the coronoid figured by Watson 68 years ago. The other bolosaur, Belebey (Fig 1), has a similar high coronoid. The putative bolosaur, Eudibamus (Fig 2), lacks this entirely.

Finally, we show that among Early Permian taxa, B. major possesses an enlarged parietal foramen, suggesting that it and perhaps other bolosaurs were diurnal.”

Watson figured this foramen 68 years ago. Not sure why the authors thought their study was worthy of an abstract. Next time bring us something a bit more “particularly novel”and give Watson 1954 a little credit.

References
Broom R 1913. On the Structure and Affinities of Bolosaurus. Bulletin of the American Museum of Natural History 32:509-516.
Case EC 1907. Description of the Skull of Bolosaurus striatus Cope. Bulletin of the American Museum of Natural History 23:653-658.
Cope ED 1878. Descriptions of extinct Batrachia and Reptilia from the Permian formations of Texas. Proceedings of the American Philosophical Society 17:505-530
Jenkins KM, Gordon CM, Napoli J and Bhullar B-A 2022. Visualizing an elusive holotype: the cranial osteology of Bolosaurus major (Parareptilia: Bolosauridae) SVP abstracts 2022: 199.
Watson DMS 1954. On Bolosaurus and the origin and classification of reptiles.Bulletin of the Museum of Comparative Zoology at Harvard College,, v. 111, no. 9444-449.