ABSTRACT
This chapter addresses the origin, classification, and distribution of the deer family (Cervidae), which arose out of the Miocene from a group of early hoofed animals in Eurasia. The large tusk-like canines of these primitive deer gradually gave way to the development of antlers that were replaced annually. Later, well-developed cervids entered North America through Beringia, across what is now Alaska 7–5 million years before present (YBP). The earliest deer in North America are represented by 3 forms that appear nearly simultaneously in the fossil record about 5 million YBP. One of those forms was the genus Odocoileus, which includes 2 species of medium-sized deer whose distribution is centered on North America: black-tailed and mule deer and white-tailed deer. Mule deer have been divided into as many as 11 subspecies, but this chapter explains, based on phylogeny reflected by concordant phenotypic and genetic characteristics, that they are more appropriately called ecotypes. Given the totality of all the evidence, the chapter demonstrates support for 5 subspecies of black-tailed and mule deer: Sitka black-tailed deer, Columbian black-tailed deer, Cedros Island mule deer, Tiburón Island mule deer, and mule deer on the mainland.
