The group at the present day is divided into Girafjidae (giraffe and okapi), Cervidae (deer), Antilocapridae (prongbuck), and Bovidae (oxen, sheep, goats, antelopes, &c.).
No true antelopes are American, the prongbuck (Antilocapra), which is commonly called "antelope" in the United States, representing a distinct group; while, as already mentioned, the Rocky Mountain or white goat stands on the borderland between antelopes and goats.
When hunting antelope (prongbuck) and deer the coyotes spread out their pack into a wide circle, endeavouring to surround their game and keep it running inside their ring until exhausted.
Female prongbuck may or may not have horns.
Gadow is of opinion that the antlers of the deer, the hornlike protuberances on the skull of the giraffe, and the true horns of the prongbuck and other hollow-horned ruminants (Bovidae) are all different stages of evolution from a single common type: the antlers of the deer being the most primitive, and the horns of the Bovidae the most specialized.