The mountain goat is an even-toed ungulate of the order Artiodactyla and the family Bovidae that includes antelopes, gazelles, and cattle. It belongs to the subfamily Caprinae, along with true goats, wild sheep, the chamois, the muskox and other species. Notably, the takins of the Himalayan region, while not a sister lineage of the mountain goat, are nonetheless very closely related and almost coeval; they and the mountain goat are a case of parallel evolution from an ancestral goat. Other members of this group are the Pseudois "blue sheep", the true goats and the Himalayan tahr. The chamois and true sheep lineages are also very closely related, while the muskox lineage is somewhat more distant. The mountain goats probably diverged from their relatives in the late Tortonian, some 7. 5 to 8 million years ago.