Authors:

Victoria Prause

Date Created:

Not specified

Course Title:

Professor:

Not specified

About Paper:

The Lance Creek Formation in Wyoming provides a wide array of vertebrate microfossils allowing for the assessment of biodiversity dynamics leading up to the Cretaceous-Paleogene (K-Pg) Mass Extinction. The lizards of the Late Cretaceous are often described solely in broader studies that combine data from multiple rock formations. As a result, a herpetofaunal assessment of the Lance Creek Formation is missing. In turn, this study can reveal how lizards in an individual ecosystem responded to the lead up to the K-Pg Mass Extinction as well as describe the current taxonomic composition of Lance Creek. Here, we present a sample of lizard jaws collected in 2023-2024. The groups Polyglyphanodontia, Teiidae, Xenosauridae, Varanidae, and Necrosauridae were present at Lance Creek. There is remarkable taxonomic overlap in lizards within the Maastrichtian age formations including Lance Creek, Hell Creek, Scollard, and Frenchman. The Lance and the Hell Creek Formations contain almost identical occurrences in the current sample with two exceptions, Socognathus and Gerontoseps. This Socognathus represents the southernmost distribution of the genus currently reported. Additionally, our findings of Socognathus unicuspis and Gerontoseps irvinensis have previously only been found at the Campanian aged Oldman Formation. Their occurrence in the Lance Creek thus extends their range in time. High-resolution micro-computed tomography (CT) scans and 3D segmentation provide insight into the internal anatomy of the jaws included in this sample. Structures such as internal canals, and dentition related details like replacement and tooth attachments are revealed, adding additional anatomical data to these lizard groups that can help to identify more fragmentary jaw pieces. Continued descriptions and collections of Lance Creek lizard faunas will further our understanding of the biogeographic links between Late Cretaceous localities as well as our understanding of the morphologies of these lizard groups. Panel Il. Cells, Genes, and Everything in Between: Insights into Living Systems

Source:

Loyola University Chicago

Topics:

No topics listed

Co-authors:

Victoria Prause