THREE PTEROSAUR TRACKWAYS FROM THE WINDY HILLS SANDSTONE, ALCOVA, WY

GMP 340 is a casting of a roughly 650x400 mm sandstone surface from the Windy Hills Sandstone Member of the Sundance Formation (164-157 Ma, Upper Jurassic), WY. The surface contains a dense concentration of 25 pterosaur footprints. Three discreet trackways are present. Each trackway records quadrupedal movement, with easily distinguishable fore and hindlimb impressions. The three trackways overlap each other, but indicate a similar direction of travel. All tracks are referable to the ichnogenus Pteraichnus. The presence of a fifth digit impression on all pes imprints, along with the greater length of the pes impressions relative to the manus impressions, identifies the smaller tracks (pes length 50-64 mm) as P. stokesi. The larger tracks (pes length 76-84 mm), in which the fifth pes digit is consistently absent and the manus length exceeds that of the pes, are identified as P. saltwashensis.