''Ursavus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of bear that existed in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

during the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

period, about 23–5.3 million years ago (Mya), existing for roughly . The genus apparently dispersed from Asia into North America about 20 Mya, becoming the earliest member of the subfamily Ursinae in the New World. 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. ''U. elmensis'', also known as the "dawn bear" is generally taken to be the earliest undisputed bear species.

Description

In life, the various species would have been between cat-sized for the smaller species and wolf-sized for the larger members of the genus phys.org news
/ref> and were mainly

omnivore An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutr ...

s or

hypocarnivore A hypocarnivore is an animal that consumes less than 30% meat for its diet, the majority of which consists of fungi, fruits, and other plant material. Examples of living hypocarnivores are the grizzly bear (''Ursus horribilis''), American black be ...

s. Most other species are known from teeth and skull fragments. A complete skull has been found in the

Gansu Gansu (, ; alternately romanized as Kansu) is a province in Northwest China. Its capital and largest city is Lanzhou, in the southeast part of the province. The seventh-largest administrative district by area at , Gansu lies between the Tibet ...

region of China of a new species from the late

, dubbed ''U. tedfordi''. It was about the size of a wolf and – except for the

giant panda The giant panda (''Ailuropoda melanoleuca''), also known as the panda bear (or simply the panda), is a bear species endemic to China. It is characterised by its bold black-and-white coat and rotund body. The name "giant panda" is sometimes us ...

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 China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

. However, Qiu ''et.al.'' (2014) have suggested reassignment of ''U. orientalis'' to the genus ''

Ballusia ''Ballusia'' is an extinct genus of small bear from the Early Miocene epoch, about 20.5-18 million years ago. Fossil remains attributed to the genus have been uncovered in Europe (Poland) and Asia (Russia, Mongolia, China).Baryshnikov G.F. & Lavro ...

'', in which case it would no longer be considered part of ''Ursavus''.

Fossil distribution

A partial list of find sites and specimen ages: *Pawnee Buttes Site,

Weld County, Colorado Weld County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 328,981. The county seat is Greeley. Weld County comprises the Greeley, CO Metropolitan Statistical Area, which is included in the Denver ...

(''U. pawniensis'') ~23.03–5.3 Ma. *Shanwang

diatomite Diatomaceous earth (), diatomite (), or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 μm to le ...

Shanwang The Shanwang National Geology Park () is located in central Shandong province, People's Republic of China, about from Linqu County. It has an area of about . The Park is well known for its fossil bearing diatomitic deposits, one of only a few such ...

(''U. orientalis'') ~17-16 Ma. May belong to the genus ''

'' *Pasalar site,

Bursa, Turkey ( grc-gre, Προῦσα, Proûsa, Latin: Prusa, ota, بورسه, Arabic:بورصة) is a city in northwestern Turkey and the administrative center of Bursa Province. The fourth-most populous city in Turkey and second-most populous in the ...

(''U. primaevus'') ~16–13.7 Ma. *Baigneaux-en-Beauc, Alsac,

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

(''U. brevirhinus'') ~16.9–16.0 Ma. *Hambach mine horizon 6C,

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

(''U. elmensis'') ~16.9–13.7 Ma. *Yost Farm Site,

Saskatchewan, Canada Saskatchewan ( ; ) is a Provinces and territories of Canada, province in Western Canada, western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on t ...

(''U. primaevus'') ~16.3–13.6 Ma. *Myers Farm Site,

Valentine Formation The Valentine Formation is a geologic unit formation or member within the Ogallala unit in northcentral Nebraska near the South Dakota border. It preserves fossils dating to the Neogene period and is particularly noted for Canid fossils. A pa ...

Webster County, Nebraska Webster County is a county in the U.S. state of Nebraska. As of the 2020 United States Census, the population was 3,411. Its county seat is Red Cloud. The county was formed in 1871, and was named for Daniel Webster. In the Nebraska license pla ...

(''U. brevirhinus'') ~16.3–13.6 Ma. *Lufeng site,

Yunnan, China Yunnan , () is a landlocked province in the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is Kunming. The province borders the C ...

(''U. depereti'') ~7-6 Ma. *Linxia Basin

Gansu, China Gansu (, ; alternately romanized as Kansu) is a province in Northwest China. Its capital and largest city is Lanzhou, in the southeast part of the province. The seventh-largest administrative district by area at , Gansu lies between the Tibe ...

(''U. tedfordi'') ~9-7 Ma.

References

{{Taxonbar, from=Q3308205 Miocene bears Messinian extinctions Miocene mammals of North America Miocene mammals of Asia Miocene mammals of Europe Miocene mammals of Africa Prehistoric carnivoran genera Aquitanian genus first appearances Fossil taxa described in 1899