A Tertiary Mammalian Fauna from the San Antonio Mountains near Tonopah, Nevada

Abstract

Discovery of fossil mammals near Tonopah, Nevada, affords opportunity not only to date significant geologic events in the west central part of the state, but also to describe the plains life of the region during Upper Miocene time. The faunaa contains nineteen species, six of which are known from no other locality. Close association of the mammalian assemblage with remains of diatoms, mollusks, and fishes in the stratigraphic record establishes a definite correlation in time between these groups. The value of the discovery as a record of Upper Miocene life is greatly enhanced by the simultaneous occurrence in a limited area of these two entirely different and complementary facies of contemporary faunas, representing arid plains and inland lake. This association furnishes interesting and detailed information as to the paleogeography of the region. Abundance of individual mammals from a quarry of narrow horizontal and vertical limitations provides a large unmixed fauna on which to base paleoecological studies.