Date of this Version
Antlers of New World deer (Cervidae), though of considerable taxonomic importance, are rarely found in deposits earlier than Late Pleistocene. The one reasonably well known Blancan deer, Bretzia pseudalces, whose antlers are known from deposits in Washington and California, is an odocoilene, closely related to Odocoileus. An analysis of antler form and distribution patterns suggests that the immigration and divergence of the New World Odocoileinae (excluding Alces and Rangifer) occurred in the latest Hemphillian and Early Blancan. Evolution of complexity in antler form in this group begins with a relatively simple pattern which lacks a brow tine immediately adjacent to the burr, possesses a single anteriorly directed tine, and has a larger (sometimes forked) posterior tine. This pattern is seen in Ozotoceras and in Capreolus. Bretzia altered this pattern by spreading the antlers laterally and by developing palmation of the posterior branch. The evolution of antlers of Odocoileus seems to begin with development of a helical form incorporating beam and anterior tine. The latter form appeared by the end of the Early Blancan, when Odocoileus apparently replaced Bretzia in the western parts of North America.