Deer constitute the second most diverse family of artiodactyla after bovids. Though of a similar build, deer are strongly distinguished from antelopes by their antlers, which are temporary and regularly regrown unlike the permanent horns of bovids. Characteristics typical of deer include long, powerful legs, a diminutive tail and long ears. Deer exhibit a broad variation in physical proportions. The largest extant deer is the moose, which is nearly tall and weighs up to . The elk stands at the shoulder and weighs . The northern pudu is the smallest deer in the world; it reaches merely at the shoulder and weighs . The southern pudu is only slightly taller and heavier. Sexual dimorphism is quite pronounced – in most species males tend to be larger than females, and, except for the reindeer, only males possess antlers.