Plionarctos

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Plionarctos
Temporal range: late Miocene–Pleistocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Suborder: Caniformia
Superfamily: Arctoidea
Family: Ursidae
Subfamily: Ursinae
Tribe: Tremarctini
Genus: Plionarctos
Frick, 1926
Species
  • P. edensis (type)
  • P. harroldorum

Plionarctos is an extinct genus of mammals of the family Ursidae (bears) endemic to North America and Europe during Miocene through Pleistocene, living from ~10.3—3.3 Mya, existing for about 7 million years.

Indarctos (10.7—9.2 Mya) preceded Plionarctos by only a few thousand years and was a contemporary of that bear and shared its habitat. Plionarctus preceded and was also contemporary with Tremarctos floridanus (4.9 million — 11,000 years ago) and shared its habitat.

Plionarctos is the oldest known genus within the subfamily of the short-faced bears (Tremarctinae) endemic to the Americas, and is believed to be ancestral to the clade.

Taxonomy[edit]

Plionarctos was named by Frick (1926). Its type is Plionarctos edensis. It was assigned to Ursidae by Frick (1926) and Carroll (1988); and to Tremarctini by Hunt (1998).[1][2]

Morphology[edit]

Body mass[edit]

Two specimens were examined by Legendre and Roth for body mass.[3]

  • Specimen 1 was estimated to weigh 165.5 kg (360 lb).
  • Specimen 2 was estimated to weigh 25.3 kg (56 lb).

Fossil distribution[edit]

Sites and specimen ages:

References[edit]

  1. ^ R. L. Carroll. 1988. Vertebrate Paleontology and Evolution. W. H. Freeman and Company, New York 1-698
  2. ^ Hunt, R. M. (1998). "Ursidae". In Jacobs, Louis; Janis, Christine M.; Scott, Kathleen L. Evolution of Tertiary Mammals of North America: Volume 1, Terrestrial Carnivores, Ungulates, and Ungulate like Mammals. Cambridge, UK: Cambridge University Press. pp. 174–195. ISBN 0-521-35519-2. 
  3. ^ S. Legendre and C. Roth. 1988. Correlation of carnassial tooth size and body weight in recent carnivores (Mammalia). Historical Biology 1(1):85-98