| 词条 | Parictis |
| 释义 |
| name = Parictis | fossil_range = {{Fossil range|Eocene|Miocene}} | regnum = Animalia | phylum = Chordata | classis = Mammalia | ordo = Carnivora | familia = Ursidae | subfamilia = Amphicynodontinae | genus = Parictis | subdivision_ranks = Species | subdivision = See text }}Parictis is the earliest genus of bears known.[1] It was a very small and graceful ursid with a skull only 7 cm long. Parictis first appeared in North America in the Late Eocene (around 38 million years ago), but it did not arrive in Eurasia until the Miocene.[2] Some suggest that Parictis may have emigrated from Asia into North America during the major sea level low about 37 mya, because of the continued evolution of the Amphicynodontinae into the Hemicyoninae in Asia.[3] Although no Parictis fossils have been found in East Asia, Parictis does appear in Eurasia and Africa, but not until the Miocene.[2] Species
Formerly classed under Parictis
References1. ^While originally classified as a bear (Ursidae), {{Cite book|author=Hunt, R. M. Jr.|year=1998|chapter=Ursidae|editor1=Janis, Christine M. |editor2=Scott, Kathleen M. |editor3=Jacobs, Louis L. |title=Evolution of Tertiary Mammals of North America, volume 1: Terrestrial carnivores, ungulates, and ungulatelike mammals|location=Cambridge, England|publisher=Cambridge University Press|pages=174–195|isbn=978-0-521-35519-3}}, others consider the entire Amphicynodontinae family to be at most bear-dogs. {{Cite journal|author1=McLellan, Bruce |author2=Reiner, David C. |lastauthoramp=yes |year=1994|chapter=A review of bear evolution|editor=Claar, James J.|title=Bears: Their Biology and Management: Ninth International Conference on Bear Research and Management|publisher=International Association for Bear Research and Management|pages=85–96|isbn=978-0-944740-04-0|display-editors=etal}} {{Wikispecies|Ursidae}}{{Portal|Palaeontology}}{{Taxonbar|from=Q3441656}}{{paleo-carnivora-stub}}2. ^1 {{Cite book|author=Kemp, T. S.|year=2005|title=The Origin and Evolution of Mammals|publisher=Oxford University Press|page=260|isbn=978-0-19-850760-4}} 3. ^Several students (Erdbrink 1953, Kurten 1966, Mitchell and Tedford 1973, Thenius 1979) suggested that the evolutionary line between the canid subfamily Amphicynodontinae and the ursid subfamily Hemicyoninae was through the genera Cephalogale and Ursavus. {{Cite journal|author1=McLellan, Bruce |author2=Reiner, David C. |lastauthoramp=yes |year=1994|chapter=A review of bear evolution|editor=Claar, James J.|title=Bears: Their Biology and Management: Ninth International Conference on Bear Research and Management|publisher=International Association for Bear Research and Management|pages=85–96|isbn=978-0-944740-04-0|display-editors=etal}} 4. ^{{cite journal | author = Chafee, R. F. | year = 1954 | title = Campylocynodon personi, a new Oligocene carnivore from the Beaver Divide, Wyoming | journal = Journal of Paleontology | volume = 28 | issue = 1 | pages = 43–46 }} 5. ^{{Cite journal|author=Hall, E. Raymond|year=1931|title=Description of a New Mustelid from the Later Tertiary of Oregon, with Assignment of Parictis primaevus to the Canidae|journal=Journal of Mammalogy|volume=12|issue=2|pages=156–158|doi=10.2307/1373915}} 6. ^{{Cite book|author=Hunt, R. M. Jr.|year=1998|chapter=Ursidae|editor1=Janis, Christine M. |editor2=Scott, Kathleen M. |editor3=Jacobs, Louis L. |title=Evolution of Tertiary Mammals of North America, volume 1: Terrestrial carnivores, ungulates, and ungulatelike mammals|location=Cambridge, England|publisher=Cambridge University Press|pages=174–195|isbn=978-0-521-35519-3}} 7. ^{{Cite journal|author=Olsen, Stanley J.|year=1958|title=Some problematical carnivores from the Florida Miocene|journal=Journal of Paleontology|volume=32|issue=3|pages=595–602|doi=10.2307/1300686}} 8. ^{{Cite book|author1=Tedford, Richard H. |author2=Frailey, David |lastauthoramp=yes |year=1976|title=Review of some Carnivora (Mammalia) from the Thomas Farm local fauna (Hemingfordian, Gilchrist County, Florida)|series=American Museum Novitates; no. 2610|location=New York|publisher=American Museum of Natural History|page=2|url=http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/2925/N2610.pdf?sequence=1}} 7 : Miocene bears|Eocene bears|Oligocene bears|Miocene genus extinctions|Transitional fossils|Eocene carnivorans|Prehistoric mammal genera |
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