Late Pleistocene Remains of an American black bear (Ursus americanus) and Two Small Vertebrates from an Oklahoma Ozark Cave

Abstract

The serendipitous discovery of fossil bear bones in a cave in northeastern Oklahoma prompted us to excavate and describe the fossils and their geologic, chronologic, and biogeographic context. We recovered the partial skeleton of a subadult (about 1-2 year-old) male Ursus americanus (American black bear) in CZ-9 Cave, Cherokee County, Oklahoma, in late Pleistocene fill sediments within the cave. The locality is at the western edge of the Ozark Highlands. A sample of enamel from a tooth of the bear yielded an AMS radiocarbon age of 10,958 ± 35 years before present. This is the first directly-dated occurrence of a black bear in the late Pleistocene of the western Ozark Highland and in Oklahoma. Two vertebrae of an unidentified snake were found in the same layer as the bear's remains and may be approximately contemporaneous. Fragmentary jaws and teeth of a large species of Blarina (short-tailed shrew) occurred in the same sedimentary unit as those containing the bear and also in another unit above them. This large shrew differs from the related smaller species Blarina hylophaga (Elliot's Short- tailed Shrew) that currently occupies the same region of eastern Oklahoma, but the fossils cannot be identified to species. The shrew fossils, too, are probably of late Pleistocene age; they may pertain to an ancestral population of larger body size than the extant local species and are about the size of extant Blarina brevicauda (Northern Short-tailed Shrew). They indicate a biogeographic or evolutionary change since the late Pleistocene in the short-tailed shrew inhabiting the Oklahoma portion of the Ozark Highland. ©2014 Oklahoma Academy of Science