The mountain goat is an even-toed
ungulate of the order
Artiodactyla and the family
Bovidae (along with
antelopes,
gazelles, and
cattle). It belongs to the subfamily
Caprinae, along with
true goats,
wild sheep, the
chamois, the
muskox and other species. The
takins of the
Himalayan region, while not a
sister lineage of the mountain goat, are nonetheless very closely related and almost
coeval to the mountain goat; they
evolved in parallel from an ancestral goat. Other members of this group are the
bharal, the true goats, and the
Himalayan tahr. The sheep lineage is 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. Given that all major caprine lineages emerged in the
Late Miocene and contain at least one but usually several species from the eastern Himalayan region, their most likely place of origin is between today's
Tibet and
Mongolia or nearby. The mountain goat's ancestors thus probably crossed the
Bering Strait after they split from their relatives, presumably before the
Wisconsinian glaciation. No
Pliocene mountain goats have been identified yet; the known
fossil record is fairly recent, entirely from North America, and barely differs from the living animals. In the
Pleistocene era, the small prehistoric mountain goat
Oreamnos harringtoni lived in the southern
Rocky Mountains.
Ancient DNA studies suggest that this was the
sister species of the living mountain goat, not its ancestor; consequently, the living species would also date back to the Pleistocene at least. The mountain goat is the
only living species in the genus
Oreamnos. The name
Oreamnos is derived from the Greek term
óros (stem
ore-) meaning "mountain" (or, alternatively,
oreas "mountain nymph") and the word
amnós meaning "lamb". == General appearance and characteristics ==