Protarctos
| Protarctos Temporal range:Pliocene–Early Pleistocene
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| Holotype skull and jaws (IVPP V10320) ofP. yinanensis,Paleozoological Museum of China | |
Scientific classification
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| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Carnivora |
| Family: | Ursidae |
| Subfamily: | Ursinae |
| Genus: | †Protarctos Kretzoi, 1945 |
| Type species | |
| †Ursus boeckhi Schlosser, 1899
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| Species | |
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Protarctosis an extinct genus of basalursine bearthat lived inNorth AmericaandEurasiaduring thePlioceneand intoEarly Pleistocene.
Description
[edit]Species ofProtarctoswere closer in size to theAmerican black bear(Ursus americanus) and theAsian black bear(U. thibetanus). They differ from other ursines in the primitive nature of their dental morphology.[1]
Systematics
[edit]
Although some paleontologists recognized the species ofProtarctosas members of the genusUrsus,at least one phylogenetic analysis from Wang et al. 2017 found the genus to be an evolutionary grade outside the last common ancestor of thespectacled bear(Tremarctos ornatus) and thebrown bear(U. arctos).[1]Thetype speciesisProtarctos boeckhi(Schlosser, 1899), followed by species referred into the genus such asP. abstrusus(Bjork, 1970),P. yinanensis(Li, 1993), andP. ruscinensis(Depéret, 1890). Each of the species can be differentiated by slight differences in the morphology of the skull, molar dental morphology and size of the specimens.[1]However, there are some authors that feel all speciesProtarctosshould be classified as subspecies or as junior synonyms ofUrsus minimus.[2][3]
Geological range
[edit]This genus small bear has been found in fossil localities from Eurasia and North America. WhileProtarctoshas been recovered from Pliocene-aged formations in Europe and North America, the genus lasted longer in Asia from the Pliocene to early Pleistocene.[2][1]
Paleobiology
[edit]Despite their primitive dental morphology in comparison with modern ursines, they still show evidence of moderate herbivory. Based on analysis on the teeth ofP. abstrusus,it has found that the teeth showed signs of dental caries. This suggests these bears were eating high amounts of a diet high in fermentable-carbohydrates or sugars, leading to the probability these bears also undergo hibernation as seen in modern species of the genusUrsus.[1]
References
[edit]- ^abcdeXiaoming Wang; Natalia Rybczynski; C. Richard Harington; Stuart C. White; Richard H. Tedford (2017)."A basal ursine bear (Protarctos abstrusus) from the Pliocene High Arctic reveals Eurasian affinities and a diet rich in fermentable sugars ".Scientific Reports.7(1): Article number 17722.Bibcode:2017NatSR...717722W.doi:10.1038/s41598-017-17657-8.PMC5735171.PMID29255278.
- ^abWagner, J. (2010). "Pliocene to early Middle Pleistocene ursine bears in Europe: a taxonomic overview".Journal of the National Museum (Prague), Natural History Series.179(20): 197–215.
- ^Baryshnikov, G. F.; Lavrov, A. V. (2013)."Pliocene bearUrsus minimusDevèze de Chabriol et Bouillet, 1827 (Carnivora, Ursidae) in Russia and Kazakhstan ".Russian Journal of Theriology.12(2): 107–118.doi:10.15298/rusjtheriol.12.2.07.