Camelops
Camelops is an extinct genus of camels that lived in North and Central America, ranging from Alaska to Honduras, from the middle Pliocene to the end of the Pleistocene. It is more closely related to the Old World dromedary and bactrian and wild bactrian camels than to the New World guanaco, vicuña, alpaca and llama; making it a true camel of the Camelini tribe. Its name is derived from the Ancient Greek (, "camel") and (, "face"), i.e. "camel-face". Taxonomy and evolution The genus Camelops first appeared during the middle Pliocene (about 4.0–3.2 million years ago (Mya) in southern North America and last being known around the latest Pleistocene (around 13,000 years ago). Despite the fact that camels are popularly associated with the deserts of Asia and Africa, the family Camelidae, which comprises camels and llamas, originated in North America during the middle Eocene period, at least 44 Mya. Both the camel and horse families originated in North America and migrated into Eurasia via the Bering Strait. Modern camels are descended from the extinct genus Paracamelus, which crossed the Bering land bridge into Asia approximately 7.5 to 6.5 million years ago. The divergence between Paracamelus and Camelops occurred about 11–10 Million years ago. Paracamelus would continue to live in North America as the High Arctic camel until the middle Pleistocene. During Pleistocene warm periods, a smaller morph of Camelops inhabited Alaska and northern Yukon. These specimens date to around 50–45 thousand years ago, and seem to have been extirpated from the area after this time, similar to the contemporaneous mastodon, the ground sloth Megalonyx, and the giant beaver Castoroides. The skull of a Camelops specimen was found above the Glenns Ferry Formation in present-day Idaho in a thick layer of coarse gravel known as the Tauna Gravels. Above this layer of gravel is another layer of fine river channel sands, where the skull was found. The age of this fossil is as young as 2 million years old and perhaps even younger, which can be inferred because it is younger than the other fossils found at the Hagerman Fossil Beds National Monument. During the late Oligocene and early Miocene periods, camels apparently underwent swift evolutionary change, resulting in several genera with different anatomical structures, ranging from those with short limbs, those with gazelle-like bodies, and giraffe-like camels with long legs and long necks. This rich diversity decreased until only a few species, such as Camelops hesternus, remained in North America, before going extinct entirely around 11,000 years ago. By the end of the Pleistocene, with the extinction of Paracamelus and Titanotylopus, Camelops was the only true camel remaining in North America and possibly both Americas. Camelops extinction was part of a larger North American extinction in which native horses, mastodons, and other camelids also died out. Possible causal factors for this megafaunal extinction include global climate change and hunting pressure from human beings. The mass extinction coincided roughly with the appearance of people belonging to the big game-hunting Clovis culture,