Symbos was formerly thought to be a separate genus, but is now known to be synonymous.[6] Its closest living relative is the muskox (Ovibos moschatus), from which it diverged around 3 million years ago.[7] It is also closely related to the contemporaneous extinct genus Euceratherium.[8][9]
Description
Unlike today's Arctic and tundra-adapted muskoxen, with their long, shaggy coats, Bootherium was physically adapted to a range of less frigid climates, and appears to have been the only species of muskox to have evolved in and remain restricted to the North American continent (the Arctic muskox's range is circumpolar, and includes the northern reaches of Eurasia as well as North America).[3]Bootherium was significantly taller and leaner than muskoxen found today in Arctic regions. Bootherium were estimated to weigh around 423.5 kg (934 lb).[10] 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.
^Bover, Pere; Llamas, Bastien; Thomson, Vicki A.; Pons, Joan; Cooper, Alan; Mitchell, Kieren J. (December 2018). "Molecular resolution to a morphological controversy: The case of North American fossil muskoxen Bootherium and Symbos". Molecular Phylogenetics and Evolution. 129: 70–76. Bibcode:2018MolPE.129...70B. doi:10.1016/j.ympev.2018.08.008. PMID30121342. S2CID52041464.
^Abraczinskas, L. M. "Pleistocene proboscidean sites in Michigan: New records and an update on published sites". Michigan Academician. 25 (4). Utah Geological Association: 443–490.
References
McKenna, Malcolm C.; Bell, Susan K. (1997). Classification of Mammals Above the Species Level. Columbia University Press. ISBN978-0-231-11013-6.
External links
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