One of the hallmark of deer is the antler (deer antler), and not the horn, which is the growth of bone that develops annually (usually in summer) especially on the stag (although there are some exceptions). There are about 34 species of deer worldwide that are divided into two major groups: the old world deer groups belonging to the subfamilia of Muntiacinae and Cervinae; as well as the new world deer group, Hydropotinae and Odocoilinae.
