Coelodonta thibetana
| Coelodonta thibetana | ||||||||||||
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| Temporal occurrence | ||||||||||||
| Middle Pliocene | ||||||||||||
| 3.7 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Coelodonta thibetana | ||||||||||||
| Deng et al., 2011 |
Coelodonta thibetana is an extinct species of woolly rhinoceros ( Coelodonta ). It inhabitedthe Tibetan highlands around 3.7 million years ago in the middle Pliocene and is the earliest known representative of its genus, which populated all of Eurasia in the Pleistocene.
features
The only skull of Coelodonta thibetana found so far was 77 cm long; due to the size of the skull, a live weight of 1.8 t is reconstructed. He had a long drawn out occiput , the nasal bone was broad and strongly rounded to the front, the distance to the intermaxillary bone was 7.4 cm. This value is higher than that of C. nihowanensis , the phylegenetically next younger species, while the classic woolly rhinoceros ( C. antiquitatis ) have both bones directly next to each other. The horns on the skull speak for a relatively large nasal horn and a smaller forehead horn. In relation to body size, the species probably had the largest horn of all rhino species, but it was obviously flattened on the side. As with the woolly rhinoceros, the head posture was very steep due to the elongated occiput. However, the bony nasal septum characteristic of the woolen rhinoceros genus was not as well developed as in later species and only showed ossification in the front third. The tooth formula of C. thibetana is I 0/0 - C 0/0 - P 3/3 - M 3/3 and thus corresponds to that of all other woolly rhinos, plus the relative high crown of the teeth. However, the lower jaw belonging to the skull still had the alveoli of the second deciduous incisor . This feature is also found in C. nihowanensis , but is absent in the younger representatives of the woolly rhinoceros.
Paleobiology
With the help of isotope studies on the enamel of the teeth of C. thibetana , conclusions could be drawn about the diet of this rhino species. The investigations were carried out on different carbon isotopes , the relationship between which provides information about the climatic conditions prevailing at the time. The values determined are similar to those measured in parallel analyzes of today's Tibetan wild asses and speak in favor of a preferred food component consisting of grasses and bushes . Similar studies on oxygen isotopes showed that the environment was more humid and cooler at the time and that a significantly drier climate only set in after the middle Pliocene.
Systematics
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Position of C. thibetana within the rhinoceros
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Coelodonta thibetana is an early and original representative of the woolly rhinoceros. It developed from a common ancestor with the steppe rhinoceros ( Stephanorhinus hemitoechus ) when it colonized the Tibetan plateau. There, an adaptation to the cold climate of the high mountains took place, similar to how yaks ( Bos mutus ) still show today . When the global climate cooled at the beginning of the Pleistocene and large parts of Eurasia froze, C. thibetana was able to slowly expand its range and advance north. The population there developed over time into the woolly rhinoceros ( C. antiquatis ), which then penetrated west.
The first description of the species by Tao Deng et al. dates from 2011 and is based on a skull found in the Zanda Basin in the western Tibetan Plateau ( IVPP V15908). In addition to the skull, the holotype also includes the lower jaw and the first three cervical vertebrae. The specific epithet refers to the place where it was found in Tibet .
swell
literature
- Tao Deng, Xiaoming Wang, Mikael Fortelius, Qiang Li, Yang Wang, Zhijie J. Tseng, Gary T. Takeuchi, Joel E. Saylor, Laura K. Säilä, Guangpu Xie: Out of Tibet: Pliocene Woolly Rhino Suggests High-Plateau Origin of Ice Age Megaherbivores . In: Science 333, September 2011. doi : 10.1126 / science.1206594 , pp. 1285-1288.
- Tao Deng, Xiaoming Wang, Mikael Fortelius, Qiang Li, Yang Wang, Zhijie J. Tseng, Gary T. Takeuchi, Joel E. Saylor, Laura K. Säilä, Guangpu Xie: Supporting Online Material for Out of Tibet: Pliocene Woolly Rhino Suggests High-Plateau Origin of Ice Age Megaherbivores . In: Science 333, September 2011.
Individual evidence
- ↑ Deng et al. 2011a , pp. 1285-1288.
- ↑ Deng et al. 2011b , p. 12.
- ↑ Deng et al. 2011b , p. 6.
- ↑ Deng et al. 2011a , p. 1286.
- ↑ Deng et al. 2011b , p. 7.
- ↑ Deng et al. 2011b , pp. 13-15.
- ↑ Deng et al. 2011a , p. 1288.
- ↑ Deng et al. 2011a , p. 1285.