Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
Quantitative Reconstruction And Two-Dimensional, Steady Flow Hydrodynamics Of The Plesiosaur Flipper, Mark Cruz Deblois
Quantitative Reconstruction And Two-Dimensional, Steady Flow Hydrodynamics Of The Plesiosaur Flipper, Mark Cruz Deblois
Theses, Dissertations and Capstones
Plesiosaurs are a group of extinct marine reptiles that thrived during the Mesozoic Era. They are unique for swimming with two hydrofoil-shaped flippers. Penguins, sea turtles, and cetaceans all have hydrofoil shaped flippers but penguins and sea turtles only use the front pair to produce thrust and cetaceans use their tail flukes. Consequently, the mode of swimming for plesiosaurs has long been debated. However, a quantitative study of the hydrodynamic properties of the flippers, which would constrain inference about their mode of swimming, has not yet been done. The main reason is that the trailing edge of the plesiosaur flipper …
Ontogenetic State Of A Juvenile Polycotylid Plesiosaur (Sauropterygia: Plesiosauria) And Its Implications For Plesiosaur Growth, Christina Joanne Byrd
Ontogenetic State Of A Juvenile Polycotylid Plesiosaur (Sauropterygia: Plesiosauria) And Its Implications For Plesiosaur Growth, Christina Joanne Byrd
Theses, Dissertations and Capstones
Understanding ontogenetic variation in plesiosaurs from the family Polycotylidae can provide insight into the evolutionary history of this group of extinct short-necked marine reptiles from the Cretaceous period. In this study, I analyzed a juvenile polycotylid plesiosaur from the University of Nebraska State Museum (UNSM 55810). UNSM 55810 came from the Pierre Shale (99-65 Ma) of Nebraska and possesses skeletal elements that include a partial skull, nearly complete pectoral and pelvic girdles, and an assortment of paddle elements. Based on several cranial characteristics, this specimen is probably referable to the genus Dolichorhynchops. Previous qualitative studies have included UNSM 55810 but …
Plesiosaur Body Shape And Its Impact On Hydrodynamic Properties, Courtney D. Richards
Plesiosaur Body Shape And Its Impact On Hydrodynamic Properties, Courtney D. Richards
Theses, Dissertations and Capstones
Despite the variability of cross-sectional body shape within Plesiosauria, its impact on plesiosaur buoyancy and stability has never been investigated. This study focused on Tatenectes, Cryptoclidus, and Muraenosaurus due to their variable body morphologies. Reconstructions were created based on measurements and photographs from fossil remains. The ability of computer models, based upon the reconstructions, to reach equilibrium after submersion, sink via lung deflation, and recover from a lateral roll was tested. For the computer models, Muraenosaurus was replaced with Thalassomedon, which had a similar morphology. Cryptoclidus and Thalassomedon recovered from submersion faster than Tatenectes. All models achieved negative buoyancy with …