A Pliocene rodent fauna from Smiths Valley, Nevada

Tertiary mammalian remains were discovered by Chester Stock and E. L. Furlong several years ago in sedimentary beds exposed along the eastern side of Smiths Valley and south of Wilson Canyon, west-central Nevada. Since then field explorations have been conducted in the region, during the summers of 1931 and 1934, by the California Institute of Technology. At one locality near the western mouth of Wilson Canyon and about fifteen miles airline from Yerington, a small collection of rodent remains was obtained, the description of which is the purpose of the present paper. Determination of Pliocene age for the deposits is afforded, chiefly, by the larger mammals in the fauna, especially the Equidrae. However, the rodent assemblage is suggestive of a similar age and indeed in one or two points indicates a stage of evolution approximating the Thousand Creek middle Pliocene fauna from northwestern Nevada