Brachyprotoma

Brachyprotoma; Temporal range: Pleistocene
	An ink drawing of an American Mastodon calf encountering a short-faced skunk, Brachyprotoma.
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Mephitidae
Genus:	Brachyprotoma; Brown 1908
Species:	B. obtusata
Binomial name
	Brachyprotoma obtusata; Cope 1899

Brachyprotoma, also known as the short-faced skunks, is an extinct genus of large skunk that inhabited Pleistocene North America, with specimens having been found from Yukon to West Virginia.^[1]^[2]^[3] There currently exists only one accepted species, Brachyprotoma obtusata.^[4]

Description

Brachyprotoma obtusata is known solely from its jaws and teeth, thus postcraneal elements are deduced based on the relatively similar hog-nosed skunks, but as a more robust form.^[5] The holotype, USNM 12045, is a damaged lower jaw that meassures 3 cm (1.2 in) long.^[6] Brachyprotoma obtusata's jaw is considered to possess several primitive characteristics, such as the large size of Premolar $^{4}$ and Molar $^{1}$ , the large size of the anterior premolars, the smaller protocone in P $^{4}$ , the weaker metaconid in M $^{1}$ and the transverse elongation of M $^{1}$ ;^[7] and some more derived traits, B. obtusata has two upper and three lower premolars, having gotten rid of the anterior-most premolars.^[8]

Etymology and Phylogeny

The generic name Brachyprotoma, from the greek brachy, meaning short; and protomē, the head and neck of a decapitated animal; in reference to the holotype's robust appearance as well as the curious lack of postcranial remains. The specific name obtusata hails from the Latin obtusitas, meaning dense.

The precise phylogenetic relationships of Brachyprotoma within Mephitidae remain controversial, it shares a dental formula with Promephitis hootoni, while its P $^{4}$ shares more characteristics with those in the genus Mephitis.^[8] As of Wang et. al. 2005,^[9] Brachyprotoma obtusata was recovered as a more derived skunk:

Mephitidae

	Mydaus

	Palaeomephitis

	Promephitis

Mephitini

Martinogale faulli

Martinogale chisoensis

Martinogale alveodens

Buisnictis

Spilogale

Brachyprotoma

	Mephitis

	Osmotherium

Conepatus

Extinction

It is unclear why Brachyprotoma obtusata went extinct along with the North American megafauna, there are several present specimens in the Bonneville Basin, Utah, circa 24.000 to 18.000 years ago. However, the species is absent in more recent strata; where only generalists remain, suggesting some degree of specialization in Brachyprotoma obtusata, perhaps related to the megafauna itself.^[10]

References

^ Harington, C. R. (1978). "Quaternary vertebrate faunas of Canada and Alaska and their suggested chronological sequence". Syllogeus. 15: 1–105.
^ Grady, F.; Garton, E. R. (2000). "Paleontology and historic field trip of the John Guilday Cave Preserve (Trout Rock)". The Caves of East-central West Virginia. 14: 241–244.
^ Youngman, Phillip M. (1986). "The extinct short-faced skunk Brachyprotoma obtusata (Mammalia, Carnivora): first records for Canada and Beringia". Canadian Journal of Earth Sciences. 23 (2): 419–424. Bibcode:1986CaJES..23..419Y. doi:10.1139/e86-043.
^ Cope, Edward D. (1899). "Vertebrate remains from Port Kennedy bone deposit". Journal of the Academy of Natural Sciences of Philadelphia. Ser. 2. 11 (2): 236–237.
^ Wang, Xiaoming; Carranza-Castañeda, Óscar (October 2008). "Earliest hog-nosed skunk, Conepatus (Mephitidae, Carnivora), from the early Pliocene of Guanajuato, Mexico and origin of South American skunks". Zoological Journal of the Linnean Society. 154 (2): 386–407. doi:10.1111/j.1096-3642.2008.00411.x.
^ Emslie, Steven D. (2012). "Paleoecology of the Upper Gunnison Basin, Colorado". UNCW Emslie Lab. Retrieved 8 May 2024.
^ Pilgrim, G. E. (1933). "A fossil skunk from Samos". American Museum Novitates (663): 13.
^ ^a ^b Şenyürek, Muzaffer (20 July 1954). "A Sudy of A Skull of Promephitis from The Pontian of Küçükyozgat". Belleten. 18 (71): 279–316. ISSN 0041-4255.
^ Wang, Xiaoming; Whistler, David P.; Takeuchi, Gary T. (30 December 2005). "A new basal skunk Martinogale (Carnivora, Mephitinae) from Late Miocene Dove Spring Formation, California, and origin of New World mephitines". Journal of Vertebrate Paleontology. 25 (4): 936–949. doi:10.1671/0272-4634(2005)025[0936:ANBSMC]2.0.CO;2. ISSN 0272-4634.
^ Schmitt, D.N.; Lupo, K.D. (2016), "Changes in Late Quaternary Mammalian Biogeography in the Bonneville Basin", Lake Bonneville - A Scientific Update, Elsevier, pp. 352–370, doi:10.1016/b978-0-444-63590-7.00013-5, ISBN 978-0-444-63590-7, retrieved 8 May 2024

[1] Harington, C. R. (1978). "Quaternary vertebrate faunas of Canada and Alaska and their suggested chronological sequence". Syllogeus. 15: 1–105.

[2] Grady, F.; Garton, E. R. (2000). "Paleontology and historic field trip of the John Guilday Cave Preserve (Trout Rock)". The Caves of East-central West Virginia. 14: 241–244.

[3] Youngman, Phillip M. (1986). "The extinct short-faced skunk Brachyprotoma obtusata (Mammalia, Carnivora): first records for Canada and Beringia". Canadian Journal of Earth Sciences. 23 (2): 419–424. Bibcode:1986CaJES..23..419Y. doi:10.1139/e86-043.

[4] Cope, Edward D. (1899). "Vertebrate remains from Port Kennedy bone deposit". Journal of the Academy of Natural Sciences of Philadelphia. Ser. 2. 11 (2): 236–237.

[5] Wang, Xiaoming; Carranza-Castañeda, Óscar (October 2008). "Earliest hog-nosed skunk, Conepatus (Mephitidae, Carnivora), from the early Pliocene of Guanajuato, Mexico and origin of South American skunks". Zoological Journal of the Linnean Society. 154 (2): 386–407. doi:10.1111/j.1096-3642.2008.00411.x.

[6] Emslie, Steven D. (2012). "Paleoecology of the Upper Gunnison Basin, Colorado". UNCW Emslie Lab. Retrieved 8 May 2024.

[7] Pilgrim, G. E. (1933). "A fossil skunk from Samos". American Museum Novitates (663): 13.

[:0-8] Şenyürek, Muzaffer (20 July 1954). "A Sudy of A Skull of Promephitis from The Pontian of Küçükyozgat". Belleten. 18 (71): 279–316. ISSN 0041-4255.

[9] Wang, Xiaoming; Whistler, David P.; Takeuchi, Gary T. (30 December 2005). "A new basal skunk Martinogale (Carnivora, Mephitinae) from Late Miocene Dove Spring Formation, California, and origin of New World mephitines". Journal of Vertebrate Paleontology. 25 (4): 936–949. doi:10.1671/0272-4634(2005)025[0936:ANBSMC]2.0.CO;2. ISSN 0272-4634.

[10] Schmitt, D.N.; Lupo, K.D. (2016), "Changes in Late Quaternary Mammalian Biogeography in the Bonneville Basin", Lake Bonneville - A Scientific Update, Elsevier, pp. 352–370, doi:10.1016/b978-0-444-63590-7.00013-5, ISBN 978-0-444-63590-7, retrieved 8 May 2024

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