Creature Feature 25

Hello, fans! Sorry for not posting last week, I've been very busy with working in the lab. This week, we will be looking at a special family of lizards from Hell Creek, the Polyglyphanodonts!

Polyglyphanodont template model, early WIP.

Polyglyphanodonts were the dominant group of lizards in both North America (Longrich et al., 2012) and Asia (Gao and Hou, 1996) during the Late Cretaceous, and died out during the KT extinction. Because many species are known only from fragmentary remains of the jaw and teeth, many are classified based on dental characters. However, this is still enough to reveal a significant level of diversity within the group. For example, Chamopsiids such as Chamops had blunt, crushing teeth that are indicative of an omnivorous diet, while species such as Peneteius had multicusped teeth somewhat akin to those of some mammals. This diversity in dentition indicates a diversity in ecology, and it is likely that Polyglyphanodonts had vastly differing diets and habitat preferences among species. Considering there were multiple different species in Hell Creek, it is likely that there was a degree of niche partitioning between them.

Polyglyphanodontians closely resembled modern teiids, and many species previously classified as teiids have been reassigned to this group (Gauthier et al., 2012). While there has been considerable dispute as to the relationships of the group, most recent analyses (Reeder et al., 2015) place them as sister to Iguania.

Well, that's this week's Creature Feature! There isn't really all that much I can say since the remains of the various species from Hell Creek are quite fragmentary, so I gave it everything I could.

Acknowledgements:

Longrich, N. R., A.-B. S. Bhullar, et al. 2012. Mass extinction of lizards and snakes at the Cretaceous-Paleogene boundary. Proceedings of the National Academy of Sciences 109(52): 21396--21401.

Gao, K.; Hou, L. 1996. Systematics and taxonomic diversity of squamates from the Upper Cretaceous Diadochta Formation, Bayan Mandahu, Gobi Desert, People's Republic of China Canadian Journal of Earth Sciences 33 (4): 578-598.

Gauthier, J. A.; Kearney, M.; Maisano, J. A.; Rieppel, O.; Behlke, A. D. B. 2012. Assembling the Squamate Tree of Life: Perspectives from the Phenotype and the Fossil Record. Bulletin of the Peabody Museum of Natural History 53: 3-308.

Reeder, Tod W.; Townsend, Ted M.; Mulcahy, Daniel G.; Noonan, Brice P.; Wood, Perry L.; Sites, Jack W.; Wiens, John J. 2015. Integrated Analyses Resolve Conflicts over Squamate Reptile Phylogeny and Reveal Unexpected Placements for Fossil Taxa. PLoS ONE 10 (3): e0118199.