ALCOVA'S PTERAICHNUS LAGERSTÄTTEN

The Alcova Reservoir region near Casper, Wyoming is well known as a pterosaur track locality including the type specimen, Pteraichnus stokesi. Although papers have been presented to the scientific community, a comprehensive study on track diversity and track abundance as well as the paleoecology of the site has not been done. New tracks have been located in the field over the past several years. Students and volunteers with Casper College set out in the summer of 2004 to map these localities. Each site was mapped using GPS and GIS technology, photographed and put into a stratigraphic framework. Lab work included petrographic analysis of the sediments containing the tracks to help facilitate the paleoecological and paleoenvironmental interpretation. The high volume of tracks allows a quantitative approach, which was used to identify any behavior patterns associated with the gait and direction of movement. With this, one major behavior pattern has been identified. Most tracks are interpreted as general ambulatory traces, representing movement from point A to point B. Additional behavior patterns include swimming and possible feeding habits. The tracks sites can be found in two stratigraphic horizons, which vary in lithology and taphonomy. This suggests that Alcova was an area frequently visited by Jurassic pterosaurs over a long period of time, through changing environments and ecology.