Ursavus is an extinct genus of bear that existed in North America, Europe, and Asia during the Miocene period, about 23–5.3 million years ago (Mya), existing for roughly 17.7 million years.[2][3] The genus apparently dispersed from Asia into North America about 20 Mya, becoming the earliest member of the subfamily Ursinae in the New World.[4] Qiu points out that if a questionable 29 million-year-old specimen of Ursavus reported in North America is validated, Ursavus may have evolved in North America and dispersed westward into Asia. The higher number of fossils in Europe grading toward eastern Asia make the westward dispersal unlikely.
Most other species are known from teeth and skull fragments. A complete skull has been found in the Gansu region of China of a new species from the late Miocene, dubbed U. tedfordi.[1] It was about the size of a wolf and – except for the giant panda and the spectacled bear – is believed to be the nearest to the common ancestor of modern bears.
Currently, the only member known from a complete skeleton is U. orientalis, found in the Shanwang diatomite of Early Miocene China.[8][10] However, Qiu et.al. (2014) have suggested reassignment of U. orientalis to the genus Ballusia, in which case it would no longer be considered part of Ursavus.[1]
^ abcdeQiu, Zhan-Xiang; et al. (2014). "A Late Miocene Ursavus skull from Guanghe, Gansu, China". Vertebrata PalAsiatica. 52 (3): 265–302.
^Kurten, Bjorn (1966). "Pleistocene bears of North America I: Genus Tremarctos, spectacled bears". Acta Zool. Fenn. 115: 1–120.
^Crusafont, M.; Kurten, B. (1976). "Bears and bear-dogs from the Vallesian of the Valles-Penedes basin, Spain". Acta Zool. Fenn. 144: 1–29.
^Zhanxiang, Qiu (2003). "Dispersals of Neogene carnivorans between Asia and North America". Bulletin of the American Museum of Natural History. 279 (279): 18–31. doi:10.1206/0003-0090(2003)279<0018:C>2.0.CO;2. S2CID 88183435.
^Derocher, Andrew E.; Ian Stirling (February 1989). "Factors affecting the evolution and behavioral ecology of the modern bears". Bears: Their Biology and Management. A selection of papers from the Eighth International Conference on Bear Research and Management (published 1990). 8: 189–204. doi:10.2307/3872919. JSTOR 3872919.
^McLellan, Bruce (1994). "A review of bear evolution" (PDF). [Proceedings of the] International Conference on Bear Research and Management. 9 (1): 85–96.
^Derocher, A. E.; Lynch, W. (2012). Polar Bears: A complete guide to their biology and behavior. Baltimore: Johns Hopkins University Press.
^ abcdLindburg, Donald G. (2004). Giant Pandas: Biology and Conservation. University of California Press. p. 46. ISBN9780520238671.
^ abYang, Hong; Shipu Yang (December 1994). "The Shanwang fossil biota in eastern China: a Miocene Konservat-Lagerstätte in lacustrine deposits" (PDF). Lethaia. 27 (4): 345–354. doi:10.1111/j.1502-3931.1994.tb01585.x.
August 27, 2023
ursavus, extinct, genus, bear, that, existed, north, america, europe, asia, during, miocene, period, about, million, years, existing, roughly, million, years, genus, apparently, dispersed, from, asia, into, north, america, about, becoming, earliest, member, su. Ursavus is an extinct genus of bear that existed in North America Europe and Asia during the Miocene period about 23 5 3 million years ago Mya existing for roughly 17 7 million years 2 3 The genus apparently dispersed from Asia into North America about 20 Mya becoming the earliest member of the subfamily Ursinae in the New World 4 Qiu points out that if a questionable 29 million year old specimen of Ursavus reported in North America is validated Ursavus may have evolved in North America and dispersed westward into Asia The higher number of fossils in Europe grading toward eastern Asia make the westward dispersal unlikely UrsavusTemporal range 23 5 3 Ma PreꞒ Ꞓ O S D C P T J K Pg NCast skull of Ursavus tedfordiScientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass MammaliaOrder CarnivoraFamily UrsidaeTribe UrsaviniGenus UrsavusSchlosser 1899Type species Ursavus brevirhinusHofmann 1887Species 1 Ursavus brevirhinus Hofmann 1887 Ursavus primaevus Gaillard 1899 Ursavus intermedius Koenigswald 1925 Ursavus pawniensis Frick 1926 Ursavus ehrenbergi Brunner 1942 Ursavus sylvestris Qiu amp Qi 1990 Ursavus isorei Ginsburg amp Morales 1998 Ursavus tedfordi Zhanxiang et al 2014 U elmensis also known as the dawn bear 5 is generally taken to be the earliest undisputed bear species 6 7 Description Edit Restoration of Ursavus middle left and other animals of the Haystack AssemblageIn life the various species would have been between cat sized for the smaller species 8 and wolf sized for the larger members of the genus 9 and were mainly omnivores or hypocarnivores Most other species are known from teeth and skull fragments A complete skull has been found in the Gansu region of China of a new species from the late Miocene dubbed U tedfordi 1 It was about the size of a wolf and except for the giant panda and the spectacled bear is believed to be the nearest to the common ancestor of modern bears Currently the only member known from a complete skeleton is U orientalis found in the Shanwang diatomite of Early Miocene China 8 10 However Qiu et al 2014 have suggested reassignment of U orientalis to the genus Ballusia in which case it would no longer be considered part of Ursavus 1 Fossil distribution EditA partial list of find sites and specimen ages Pawnee Buttes Site Weld County Colorado U pawniensis 23 03 5 3 Ma Shanwang diatomite Shanwang China U orientalis 10 17 16 Ma 8 May belong to the genus Ballusia 1 Pasalar site Bursa Turkey U primaevus 16 13 7 Ma Baigneaux en Beauc Alsac France U brevirhinus 16 9 16 0 Ma Hambach mine horizon 6C Germany U elmensis 16 9 13 7 Ma Yost Farm Site Saskatchewan Canada U primaevus 16 3 13 6 Ma Myers Farm Site Valentine Formation Webster County Nebraska U brevirhinus 16 3 13 6 Ma Lufeng site Yunnan China U depereti 7 6 Ma 8 Linxia Basin Gansu China U tedfordi 9 7 Ma 1 References Edit a b c d e Qiu Zhan Xiang et al 2014 A Late Miocene Ursavus skull from Guanghe Gansu China Vertebrata PalAsiatica 52 3 265 302 Kurten Bjorn 1966 Pleistocene bears of North America I Genus Tremarctos spectacled bears Acta Zool Fenn 115 1 120 Crusafont M Kurten B 1976 Bears and bear dogs from the Vallesian of the Valles Penedes basin Spain Acta Zool Fenn 144 1 29 Zhanxiang Qiu 2003 Dispersals of Neogene carnivorans between Asia and North America Bulletin of the American Museum of Natural History 279 279 18 31 doi 10 1206 0003 0090 2003 279 lt 0018 C gt 2 0 CO 2 S2CID 88183435 Derocher Andrew E Ian Stirling February 1989 Factors affecting the evolution and behavioral ecology of the modern bears Bears Their Biology and Management A selection of papers from the Eighth International Conference on Bear Research and Management published 1990 8 189 204 doi 10 2307 3872919 JSTOR 3872919 McLellan Bruce 1994 A review of bear evolution PDF Proceedings of the International Conference on Bear Research and Management 9 1 85 96 Derocher A E Lynch W 2012 Polar Bears A complete guide to their biology and behavior Baltimore Johns Hopkins University Press a b c d Lindburg Donald G 2004 Giant Pandas Biology and Conservation University of California Press p 46 ISBN 9780520238671 phys org news a b Yang Hong Shipu Yang December 1994 The Shanwang fossil biota in eastern China a Miocene Konservat Lagerstatte in lacustrine deposits PDF Lethaia 27 4 345 354 doi 10 1111 j 1502 3931 1994 tb01585 x Retrieved from https en wikipedia org w index php title Ursavus amp oldid 1170070951, wikipedia, wiki, book, books, library,
