Biostratigraphic and Biogeographic Implications of Miocene Mammals from Jackson Hole, Wyoming

Abstract

Under the auspices of the U. S. Geological Survey and the University of Washington, detailed investigations of Miocene vertebrates and sediments in Jackson Hole, Wyoming commenced in 1979. Principal objectives of this research include: 1. Documenting the occurrence of mid-Tertiary mammals from Jackson Hole. Although fossils have been reported from Miocene rocks in the region (Love, 1956; Sutton and Black, 1972), existing collections are small. 2. Biostratigraphic correlation of isolated vertebrate localities throughout the northern Rocky Mountains with the superimposed localities in and near Grand Teton National Park. Such correlation will help determine whether regional or local tectonic events caused downwarping of Jackson Hole and uplift of the Teton Range. 3. Clarifying geographic variation of some small mammals through long periods of geologic time by comparison of West Coast (Rensberger, 1971, 1973;· Martin, 1979), Great Plains (Macdonald, 1963, 1970; Galbreath, 1953; Wilson, 1960), and the newly collected Jackson Hole faunas. This report summarizes accomplishments of the 1980 field season. Approximately one more season of field work and an ensuing year of data analysis are required before a final report will be available.