Late Pleistocene Vertebrates from Bechan Cave, Colorado Plateau, Utah (abstract) [Vertébrés du Pléistocène final de la grotte de Bechan, Plateau du Colorado, Utah].

Résumé

Typically the vertebrate paleoecologist is left with only skeletal remains to provide a reconstruction of the various animals, their diet, and their associated biotic community. The hyperarid climate of the Colorado Plateau provides an unusual preservational environment where little organic decay has occurred since deposition during the Wisconsin Glacial. The Pleistocene organic layer in Bechan Cave contains +300 cubic meters of predominantly plant remains and herbivore dung. This is a unique deposit in that it contains a great quantity of dry-preserved animal remains. Megaherbivore species identified from dung include: Mammathus sp., Euceratherium collinum, Nothrotheriops shastensis, Bison sp., and cf. Oreamnos harringtoni. Only two skeletal remains of a large species have been recovered from the excavations (Euceratherium: LM/2, fragment of a metapodial). Microfaunal studies of Pleistocene deposits are rare on the Colorado Plateau outside of the Grand Canyon. Fine sieving of the excavated deposits has permitted the recovery of an associated microfauna. Identified species from Bechan Cave include: Scaphiopus intermontanus, S. cf. bombifrons, Pituophis melanoleucus, Crotalus cf. viridis, a grouse-sized bird, Brachylagus idahoensis, Marmota flaviventris, Spermophilus sp., Thomomys sp., Lagurus curtatus, Microtus sp., and Neotoma cinerea.