''Indarctos'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of bear, present in

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

, and

Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...

during the

Miocene The Miocene ( ) is the first epoch (geology), 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 mea ...

. It was present from ~11.1 to 5.3 Ma, existing for approximately . The oldest member is from

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

(~11.1—7.7 Ma) and youngest is (~9.0—5.3 Ma) from

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

. In North America this animal was contemporary with '' Plionarctos'' (~10.3—3.3 Ma).

Discovery, history and taxonomy

Discoveries

A molar (designated to MNA 1839/km-83) discovered from the

Karabulak formation Karabulak may refer to: ;Places *Karabulak, Azerbaijan (disambiguation), Karabulak, Azerbaijan, alternative name of several localities in Azerbaijan *Karabulak, Kazakhstan, an urban-type settlement in Kazakhstan *Karabulak (South Kazakhstan), a vil ...

in 1988 was tentatively assigned to ''Indarctos sp''. In 2017 it was re examined and assigned to ''I. punjabensis.'' The tooth was found to belong to a young individual, which may be a male, and is the largest tooth known from the species. This might be due to

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

since extant male bears are larger than the females.

Species

''Indarctos'' is known from several species spread widely across Eurasia, North America, and

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

, however, most of them are known from fragmentary remains which leaves us with insufficient knowledge of the

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, lifestyle,

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

and

paleoecology Paleoecology (also spelled palaeoecology) is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs ...

of some species. These species are usually established based on poor remains, where the presence of sexual dimorphism, paleogeographical variation and individual variation is not taken into account, resulting in a number of species whose taxonomic validity is doubted. The following are some species of this genus: ''I. arctoides'': This species had an omnivorous diet, and it was ancestral to the later ''I. punjabensis''. ''I. punjabiensis'': This species is the geologically youngest and last species of ''Indarctos''. It had a wide distribution 6.3–6.5 Ma during the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

, across Eurasia. It is known from the Karabulak formation of

, to

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and the Dhon Pathan formation of Indo-

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

. It descended from the earlier ''I. arctoides'', but unlike its ancestor, it was

omnivorous An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize ...

and bigger in size. Based on the resemblance of its

forelimbs A forelimb or front limb is one of the paired articulated appendages ( limbs) attached on the cranial (anterior) end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used inst ...

to those of the modern

brown bear The brown bear (''Ursus arctos'') is a large bear native to Eurasia and North America. Of the land carnivorans, it is rivaled in size only by its closest relative, the polar bear, which is much less variable in size and slightly bigger on av ...

, it possibly had similar locomotor adaptations. Evolutionary features such as this led to the migration of ''Indarctos''-like bears into North America. At the end of the

, ''Indarctos punjabiensis'' went

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

as the last species of its genus.

Description

''I. arctoides'' was sexually dimorphic with males weighing , while females weighed .

Distribution

Some sites and specimen ages: *Box T Site,

Lipscomb County, Texas Lipscomb County ( ) is a county located in the U.S. state of Texas. As of the 2020 census, its population was 3,059. Its county seat is Lipscomb. The county was created in 1876 and organized in 1887. It is named for Judge Abner Smith Lipscom ...

~9.3—9.2 Ma. *Rattlesnake site,

Grant County, Oregon Grant County is one of the List of counties in Oregon, 36 counties in the U.S. state of Oregon. As of the 2020 United States census, 2020 census, the population was 7,233, making it Oregon's fourth-least populous county. The county seat is Can ...

~10.3—4.9 Ma. *Withlacoochee River Site 4A, Marion County,

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

(''Indarctos sp.'') ~10.3—4.9 Ma. *Lufeng,

Yunnan, China Yunnan; is an inland province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces of Guizhou, Sichuan, ...

''(I. atticus)'' ~9—5.3 Ma. *Yulafli (CY),

Thrace Thrace (, ; ; ; ) is a geographical and historical region in Southeast Europe roughly corresponding to the province of Thrace in the Roman Empire. Bounded by the Balkan Mountains to the north, the Aegean Sea to the south, and the Black Se ...

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

(''I. arctoides'') ~9.7—8.7 Ma. *Batallones-3, Madrid Basin,

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

(''I. arctoides'') ~11.6—5.3 Ma.Abella J, Valenciano A, Pérez-Ramos A, Montoya P, Morales J (2013) On the Socio-Sexual Behaviour of the Extinct Ursid ''Indarctos arctoides'': An Approach Based on Its Baculum Size and Morphology. PLoS ONE 8(9): e73711. doi:10.1371/journal.pone.0073711

Paleoecology

, the species ''I. punjabiensis'' is known from the Karabulak formation which dates to 6.3–6.5 Ma (

). It coexisted with three mustelids ('' Martes sp., Promeles sp., Plesiogulo crassa Teilhard''), three

feliforms Feliformia is a suborder within the order Carnivora consisting of "cat-like" carnivorans, including Felidae, cats (large and small), hyenas, mongooses, viverrids, and related taxa. Feliformia stands in contrast to the other suborder of Carnivora, ...

('' Adcrocuta eximia, Hyaenictitherium hyaenoides orlovi,'' ''Amphimachairodus kurteni''), four perissodactyls ( ''Hipparion hippidiodus'', '' H. elegans'', '' Chilotherium sp., Sinotherium zaisanensis)'', and six

artiodactyls Artiodactyls are placental mammals belonging to the order Artiodactyla ( , ). Typically, they are ungulates which bear weight equally on two (an even number) of their five toes (the third and fourth, often in the form of a hoof). The other thre ...

('' Cervavitus novorossiae, Procapreolus latifrons, Samotherium cf. irtyshense, Paleotragus (Yuorlovia) asiaticus, Tragoportax sp.,

Gazella dorcadoides A gazelle is one of many antelope species in the genus ''Gazella'' . There are also seven species included in two further genera; ''Eudorcas'' and ''Nanger'', which were formerly considered subgenera of ''Gazella''. A third former subgenus, ''P ...

''). The climate that ''Indarctos punjabensis'' lived in was mild and arid. It was a habitat of wide, open

steppes In physical geography, a steppe () is an ecoregion characterized by grassland plains without closed forests except near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the tropical and subtropical gr ...

References

{{Taxonbar, from=Q2892917 Fossil taxa described in 1913 Miocene bears Miocene mammals of North America Miocene mammals of Asia Miocene mammals of Africa Prehistoric mammals of Europe Prehistoric carnivoran genera Articles containing video clips Ailuropodinae