Ecology and Evolutionary Biology Seminar

“Air Giants: Reconstructing the Anatomy and Flight Performance of Azhdarchid Pterosaurs” presented by ​Michael Habib, Department of Cell & Neurobiology, University of Southern California

Wednesday, May 7th, 2014

2320 Life Sciences Building

Abstract:

Pterosaurs were the first vertebrates to evolve powered flight, and they show a repeated tendency in the fossil record to evolve large body sizes as flying animals. The azhdarchids, in particular, were a group of Cretaceous pterosaurs that included the largest flying animals known in biology. The largest azhdarchid pterosaurs described to date had wingspans of approximately 10.5 meters, though new fossils suggest that some individuals grew even larger. The ecological and mechanical implications of giant size in azhdarchid pterosaurs have been topics of heated debate for over 40 years. Combining quantitative bone biomechanics and fluid theory suggests that giant size in azhdarchids was obtainable through a combination of pneumaticity, quadrupedal gait, and passively cambering soft tissue wings. I present the first reconstructions of the anatomy of Quetzalcoatlus based on full skeletal measurements and bone cross-sections. Based on these updated body models, I find no evidence that the largest azhdarchids had reached a mechanical limit for flight. I propose that long-range foraging made have promoted the evolution of large size in pterosaurs, and I review the potential advantages of gigantism for flying animals.

Refreshments will be served at 11:40 a.m.