''Bootherium'' (Greek: "ox" (boos), "beast" (therion)) is an extinct

bovid The Bovidae comprise the biological family of cloven-hoofed, ruminant mammals that includes cattle, bison, buffalo, antelopes, and caprines. A member of this family is called a bovid. With 143 extant species and 300 known extinct species, ...

genus from the middle to late

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

of North America which contains a single species, ''Bootherium bombifrons''.McKenna & Bell, 1997, p. 442. Vernacular names for ''Bootherium'' include Harlan's muskox, woodox, woodland muskox,The Academy of Natural Sciences
helmeted muskox, or bonnet-headed muskox. ''Bootherium'' was one of the most widely distributed

muskox The muskox (''Ovibos moschatus'', in Latin "musky sheep-ox"), also spelled musk ox and musk-ox, plural muskoxen or musk oxen (in iu, ᐅᒥᖕᒪᒃ, umingmak; in Woods Cree: ), is a hoofed mammal of the family Bovidae. Native to the Arctic, ...

species in North America during the Pleistocene era. It is most closely related to the modern

, from which it diverged around 3 million years ago, it is possibly synonymous with '' Euceratherium'', although this is uncertain.

Taxonomy

Fossils have been documented from as far north as

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, Oklahoma,

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and

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. The species became extinct approximately 11,000 years ago at the end of the last

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

''Symbos'' was formerly thought to be a separate genus, but is now known to be synonymous. The closest relative of ''Bootherium'' is the extant muskox ''

Ovibos moschatus The muskox (''Ovibos moschatus'', in Latin "musky sheep-ox"), also spelled musk ox and musk-ox, plural muskoxen or musk oxen (in iu, ᐅᒥᖕᒪᒃ, umingmak; in Woods Cree: ), is a Ungulate, hoofed mammal of the family Bovidae. Native to the ...

''. However, unlike the tundra muskox, ''Bootherium'' was physically adapted to a range of less frigid climates and appears to have been the only ox to have evolved in and remain restricted to the North American continent. ''Bootherium'' was significantly taller and leaner than muskoxen found today in

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, N ...

regions. ''Bootherium'' were estimated to weigh around .Paleobiology Database: Bootherium bombifrons
/ref> Other differences were a thicker skull and considerably longer snout. The horns of ''Bootherium'' were situated high on the skull, with a downward curve and were fused along the midline of the skull, unlike tundra muskoxen whose horns are separated by a medial groove. Three other species of musk oxen co-inhabited North America during the Pleistocene era. Besides the surviving tundra muskox, the extinct shrub-ox (''Euceratherium collinum'') and Soergel's ox (''Soergelia mayfieldi'') were also present.

Notes

References

External links

* http://nature.ca/notebooks/english/helmet.htm * https://web.archive.org/web/20080407140851/http://www.ansp.org/museum/jefferson/otherFossils/bootherium.php {{Taxonbar, from1=Q38720035, from2=Q1603113 Prehistoric bovids Prehistoric mammals of North America Pleistocene mammals of North America Pleistocene even-toed ungulates Pleistocene species extinctions Taxa named by Joseph Leidy Fossil taxa described in 1852 Taxa named by Richard Harlan Prehistoric even-toed ungulate genera