PTEROSAUR SWIMMING TRACKS: A CASE FOR BUOYANCY

Pterosaur tracks and trackways are known from the Windy Hill Sandstone and the lower Morrison Formation, Upper Jurassic, of Central Wyoming. New finds, research, and documentation continues through today by members of the Tate Geological Museum of Casper College and others. To date, well over 100 tracks of Pteraichnus sp. have been documented. Most of these tracks and trackways present a quadrupedal walking behavior among Jurassic pterosaurs. However, as a result of continuing research, track patterns of a new type were collected showing swimming-like behavior. Based on the morphology of these tracks, it is suggested that the track maker was also buoyant while making these impressions; a trait that has been a topic of debate. This new material will introduce the concept of buoyancy and add to our understanding of pterosaur morphology and behavior.