| 词条 | Plionarctos |
| 释义 |
| name = Plionarctos | image = | image_caption = Reconstruction of head | fossil_range = {{Fossil range|late Miocene|Late Pliocene}} Possiblly survived until 1.8 million years ago in the Pleistocene | regnum = Animalia | phylum = Chordata | classis = Mammalia | ordo = Carnivora | subordo = Caniformia | superfamilia = Arctoidea | familia = Ursidae | subfamilia = Tremarctinae | genus = †Plionarctos | genus_authority = Frick, 1926[1] | type_species =†Plionarctos edensis | type_species_authority = Frick, 1926 | subdivision_ranks = Species | subdivision = †P. harroldorum (Tedfored & Martin, 2001)[2] †P. edensis (Frick, 1926) }} 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. TaxonomyPlionarctos 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).[3][4]MorphologyBody massTwo specimens were examined by Legendre and Roth for body mass.[5]
Fossil distributionSites and specimen ages:
References1. ^{{cite journal|last1=Frick|first1=Childs|title=The Hemicyoninæ and an American Tertiary Bear|journal=Bulletin of the American Museum of Natural History|date=1926|volume=56|issue=1|pages=111–119|hdl=2246/1321}} {{Taxonbar|from=Q3445718}}2. ^{{cite journal|last1=Tedford|first1=Richard H.|last2=Martin|first2=James|title=Plionarctos, a tremarctine bear (Ursidae: Carnivora) from western North America|journal=Journal of Vertebrate Paleontology|date=2001|volume=21|issue=2|pages=311–321|doi=10.1671/0272-4634(2001)021[0311:PATBUC]2.0.CO;2|jstor=20061955}} 3. ^R. L. Carroll. 1988. Vertebrate Paleontology and Evolution. W. H. Freeman and Company, New York 1-698 4. ^{{cite book |editor1-last=Jacobs |editor1-first= Louis |editor2-last= Janis |editor2-first= Christine M. | editor3-last= Scott | editor3-first= Kathleen L. |title=Evolution of Tertiary Mammals of North America: Volume 1, Terrestrial Carnivores, Ungulates, and Ungulate like Mammals |publisher=Cambridge University Press |location=Cambridge, UK |year=1998 |isbn=0-521-35519-2 | first1=R. M. |last1=Hunt | chapter= Ursidae |pages= 174–195 }} 5. ^{{cite journal|last1=Legendre|first1=Serge|last2=Roth|first2=Claudia|title=Correlation of carnassial tooth size and body weight in recent carnivores (mammalia)|journal=Historical Biology|date=1988|volume=1|issue=1|pages=85–98|doi=10.1080/08912968809386468}} 7 : Pliocene bears|Miocene bears|Pleistocene bears|Pleistocene genus extinctions|Pliocene mammals of North America|Pliocene mammals of Europe|Prehistoric mammal genera |
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