Tremarctos floridanus
| Tremarctos floridanus | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temporal occurrence | ||||||||||||
| Pliocene to Holocene | ||||||||||||
| 7.3 million years to around 8,000 years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Tremarctos floridanus | ||||||||||||
| ( Gidley , 1928) | ||||||||||||
Tremarctos floridanus is an extinct species of predator from the bear family(Ursidae). It is a representative of the short-snouted bears (Tremarctinae), whichare extinctwith the exception of the spectacled bear ( Tremarctos ornatus )living in South America. Tremarctos floridanus lived in North America and, like the spectacled bear and the European cave bear, probablyatemainly vegetarian fruits and other parts of plants.
features
Tremarctos floridanus was significantly larger than the spectacled bear, and its body was also larger and heavier. It had longer legs, a barrel-shaped body and an elongated neck, and a large head.
The bear had the typical teeth for the genus Tremarctos , which are characterized by relatively small teeth compared to other Tremarctinae. The lower jaw has a clear pit in front of the insertion of the masseter muscle , which can only be found in this form in the Tremarctinae. Compared to the spectacled bear, Tremarctos floridanus had smaller premolers and elongated molars .
distribution
Remains of Tremarctos floridanus have been found in North America in various parts of what is now the United States and northern Mexico . The oldest finds, dated to the Blancan, come from Idaho and southern California . Most of the finds come from Florida , where the bear has been identified for the Irvingtonian and Rancholabrean. Further finds from the Rancholabrean were found in Texas , New Mexico , Kentucky , Tennessee and Georgia as well as from the Mexican state of Nuevo León .
Way of life
Tremarctos floridanus lived terrestrially and probably ate almost exclusively on plants. In this respect it was similar to its relative, the spectacled bear, as well as the cave bear ( Ursus spelaeus ) native to Europe . He had various convergent features compared to the cave bear , including the teeth that specialize in vegetarian food, the masticatory muscles and the compact build.
In its habitat, Tremarctos floridanus often occurred together with the American black bear ( Ursus americanus ), which feeds on hunted animals to a significantly greater extent.
Evolution and systematics
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Phylogenetic system of bears according to Krause et al. 2008
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The first scientific description of Tremarctos floridanus was in 1928 by JW Gidley. He assigned the species as Arctodus floridanus to the then already known genus of the short- faced bear ( Arctodus ) with the short- faced bear (Arctodus simus). The Finnish paleontologist Björn Kurtén first placed the species in the genus Tremarctos in 1963 , to which only the spectacled bear ( Tremarctos ornatus ) that is still alive today is assigned. The genus Tremarctos appeared with Tremarctos floridanus in the late Miocene to early Pliocene 7.3 to 4.3 million years ago, when the genera of the Tremarctinae separated. This species probably lived in Florida until 8,000 years ago and thus also occurred in the Holocene . However, the two known Tremarctos species did not split up until the late Pleistocene to early Holocene, around 0.13 million years ago. As a result, the spectacled bear is considered to be the youngest species of all recent bears in evolution.
Within the bears, the genus is listed as a subfamily of the short- nosed bears (Tremarctinae), which also contains several extinct species such as the short- faced bears ( Arctodus simus ), which were native to North America until the end of the Pleistocene about 11,000 years ago . The Tremarctinae are compared to the real bears (Ursinae).
supporting documents
- ↑ a b c d e f Björn Kurtén , Elaine Anderson: Pleistocene Mammals of North America. Columbia University Press, New York 1980; Pp. 178–180 ( Google Books )
- ↑ a b c Johannes Krause et al. : Mitochondrial genomes reveal an explosive radiation of extinct and extant bears near the Miocene-Pliocene boundary. BMC Evolutionary Biology 2008, doi : 10.1186 / 1471-2148-8-220
- ^ JW Gidley: A new species of bear from the Pleistocene of Florida. Journal of the Washington Academy of Sciences 18, 1928: 430-433.
- ^ Tremarctos in the Paleobiology Database.
- ^ A b "Evolution, Phylogeny and Taxonomy." In: Shaenandhoa García-Rangel: Andean bear Tremarctos ornatus natural history and conservation. Mammal Review 42 (2), 2012; Pp. 90-91.
literature
- Björn Kurtén , Elaine Anderson: Pleistocene Mammals of North America. Columbia University Press, New York 1980; Pp. 178–180 ( Google Books )