Desert Tortoises (Gopherus agassizii) from Pleistocene Sediments in Cathedral Cave, White Pine County, Nevada

摘要

We report two fossil specimens of the desert tortoise (Gopherus agassizii) from Cathedral Cave, White Pine County, Nevada. These specimens are diagnosed as G. agassizii based on morphology of the scute sulcus on the entoplastron and anterior constriction and morphology of the scute sulcus of the epiplastron. The fossils have a maximum age of 146,020 plus or minus 2,584-151,200 plus or minus 4,400years, and represent the first record of Pleistocene turtles from within the hydrographic Great Basin. Documentation of fossil turtles within the east-central Great Basin at this time interval suggests that turtles were extirpated from much of the Great Basin by environmental changes or other factors that took place sometime between deposition of the Cathedral Cave deposit and the latest Pleistocene, when diverse reptilian assemblages across the Great Basin were devoid of turtles.