Reconstructing the ecological relationships of the latest Cretaceous Antarctic dinosaurs and how functional tooth morphology influenced diet and ecological niche among basal Ornithopod dinosaurs

• Main Author: Broxson, Ian
• Format: Text
• Language: unknown
• Published: EWU Digital Commons 2023
• Subjects: Other Ecology and Evolutionary Biology; Paleobiology; Paleontology; Antarc*; Antarctic; Antarctic Peninsula; Antarctica
• Online Access: https://dc.ewu.edu/theses/841; https://dc.ewu.edu/context/theses/article/1839/viewcontent/Broxson_I_2023.pdf

Of the final three connected Gondwanan landmasses, the dinosaur fossil record of Antarctica in the Cretaceous is the least complete. Most dinosaur faunas in this time period (145 Ma to 66.0 Ma) are widely separated geographically and temporally from one another by million years. However, a group of non-avian dinosaurs from the James Ross Basin (JRB) of the Antarctic Peninsula, composed of two elasmarians, a parankylosaurian ankylosaur, a hadrosaur and a suspected megaraptor, all are represented by fragmentary remains have emerged from the same horizon of the Sandwich Bluff Member (SBM) of the López de Bertodano Formation and were thus, all contemporaneous with one another. This allows us to construct an ecological model of this local fauna, a first for Antarctica in this time period. This study is important in characterizing not only local ecological relationships, but will also provide an in-depth analysis of functional tooth morphology that has greater implications for other ornithischians as a whole. To accomplish this goal there are a variety of methods that can be employed to garner ecological data from this long extinct group of dinosaurs. Methods that will be used to construct this model include determining whether body size can be a predictor for tooth morphology and thus diet. This study will also include an analysis of dental data of related elasmarians from other landmasses to help determine functional morphology of the dentition of this group of dinosaurs. We used both regression analyses and ranked correlations between body size, tooth size and tooth morphology. With this data, we were able to construct phylogenetic trees based on tooth morphology to help determine whether body size, biogeography, or other factors influence certain tooth structures. Finally, it will also be important to understand the climatic shifts and the flora that was present in the James Ross Basin and how that affected tooth morphology.