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Brown Bear (Ursus arctos) Fact Sheet: Taxonomy & History

Taxonomic History & Nomenclature


  • Taxonomy: see right panel
  • 16 subspecies listed for Brown Bears (Ursus arctos)
  • Other taxonomists say populations in Eastern Europe, Siberia, Alaska, Canada, and the U.S. are probably not genetically distinct enough to merit separate taxonomic designation. (Leonard et al 2000)

Common Names

  • Brown Bear, Grizzly Bear, Kodiak Bear
  • Brown Bears have traditionally been referred to as Grizzly Bears in the non-coastal western U.S.

Scientific Name

  • Ursus is Latin for "bear"
  • arctos comes from Greek arktos, meaning bear

Evolutionary History

Phylogeny (Krause 2008) (Yu et al 2007)

  • Origins of the Ursidae family: 15-20 million years ago (mid-Miocene)
  • Brown Bears (includes Grizzly Bears) and Polar Bears diverged from the Black and Sun Bears in the last 6.1 million years ago (Pliocene)
  • An ancestor of Brown and Polar Bears diverged from the European Cave Bears (U. spelaeus) around 1.6 million years ago. (Bon et al 2008)
    • Cave Bears are sister to a clade of Brown and Polar Bears (Agnarsson et al 2010)
  • Estimates vary widely for timing of Brown Bear and Polar Bears divergence (Lindqvist et al 2010)
    • 1,320,000 to 200,000 years ago.
  • First Brown Bears lived in China, about 500,000 years ago (Pasitschniak-Arts 1993)
  • Brown Bears and Cave Bears lived at the same time in Europe beginning about 250,000 years ago (Pasitschniak-Arts 1993)
  • Brown Bears replaced Cave Bears in Great Britain about 10,000 years ago
  • Brown Bears first appeared 50-70,000 years ago in eastern Beringia (land bridge between Siberia and Alaska during Pleistocene Ice Ages) (Leonard et al 2000)
    • By about 36,000 years ago three main clades of brown bears in Beringia.
    • From Beringia, Brown Bears spread into Canada, Alaska, and the lower U.S.
    • Appeared in lower U.S. 13,000 years ago, at end of last Ice Age when ice-free corridor available.
  • Polar Bears are closest relatives of Brown Bears.
    • Polar-Bear/Grizzly hybrids are fertile (Davis 1950)

Cultural History

Popular cultural references

  • Documentary appearances
    • Walking with Giants: The Grizzlies of Siberia - 1999, PBS
      • This episode from season 17 of the Nature program takes a look at bears that have never been with people before.
    • Showdown at Grizzly River - 2000, PBS
      • This episode from season 18 of the Nature program takes viewers to Alaska, where the competition for salmon is fierce.
    • The Good, the Bad, and the Grizzly - 2004, PBS
      • This episode from season 23 of the Nature program allows viewers to witness grizzly bears in Yellowstone.
    •  Clash: Encounters of Bears and Wolves - 2010, PBS
      • This episode from season 28 of the Nature program shows two fierce competitors as they test their strategies for survival in Yellowstone.
    • Bears of the Last Frontier - 2011, PBS
      • This 3 part episode arc from season 29 of the Nature program displays "City of Bears," "The Road North," and "Arctic Wanderers."
    • Fortress of the Bears - 2012, PBS
      • In this episode from season 30 of Nature, Yellowstone National Park is once again the backdrop as viewers can observe grizzly bears.
    • Bears - 2014, Disneynature
      • This film is based on a year in the life of a bear family, a mother and her two cubs, in Alaska.


Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Ursidae (bears)

Genus: Ursus

Species: Ursus arctos (Brown Bear, Grizzly Bear)

Subspecies: currently debated among taxonomists; see Gippoliti (2016) for discussion

Describer (Date): Linnaeus 1758

Source: Integrated Taxonomic Information System (ITIS); downloaded April 2010.

Brown Bear

drawing of a Brown bear

Brown Bear, Ursus arctos

Image credit: © Biodiversity Heritage Library Flick. Some rights reserved.

Page Citations

Agnarsson et al (2010)
Bonn et al (2008)
ITIS (2010)
Krause et al (2008)
Leonard et al (2000)
Lindqvist et al (2010)
Yu et al (2007)
Pasitschniak-Arts (1993)

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