Vulpes qiuzhudingi
| Vulpes qiuzhudingi | ||||||||||||
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| Temporal occurrence | ||||||||||||
| Early Pliocene | ||||||||||||
| 5.08 to 3.60 million years | ||||||||||||
| Locations | ||||||||||||
| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Vulpes qiuzhudingi | ||||||||||||
| Wang et al. , 2014 |
Vulpes qiuzhudingi is an extinct species of real fox . It lived around 5 to 3.6 million years ago in the early Pliocene on the highlands of Tibet and its characteristics resembled the arctic fox ( Vulpes lagopus ) that lives today.
The remains of Vulpes qiuzhudingi include a few jaw fragments found in the Zanda Basin and in the central Kunlun in the Kunlun Pass Basin. On the basis of fossils of this species as well as some other mammalian fossils from the Tibetan high plateau, the research team led by vertebrate biologist Wang confirmed their "out-of-Tibet" hypothesis, according to which animal species adapted to extreme cold developed and developed in the Tibetan high mountains before the Ice Age then spread across the arctic regions of the northern hemisphere.
features
Vulpes qiuzhudingi was likely the size of a large male red fox , around 20% larger than the arctic fox living today . Like the arctic fox, Vulpes qiuzhudingi had teeth adapted to a high proportion of meat (hypercarnivor). The size reconstruction was reconstructed solely on the existing dentition parts, further features are unknown.
The description was based on a few parts from the dentition of various representatives of the species. The holotype IVPP V18923 is an almost complete left lower jaw bone with individual teeth and tooth cavities. The canine , the second premolar and the first molar are preserved, alveoli exist from the first, third and fourth premolars and the second molar. There is also a fragment of the right branch of the lower jaw with some broken teeth from the canine to the fourth premolar (Fossil IVPP V18924) and around a single second molar (Fossil IVPP V19060). The known fossils can be differentiated from today's foxes by the details of their teeth. The two molars m1 and m2 are typical with sharp talonids, which are dominated by high hyperconids and have a reduced or no entoconid. The molar m3 is missing.
Locations and chronological classification
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The available fossil material is estimated to be 3.6 to 5 million years old. The fossils for the first description come from the Zanda Basin and the Kunlun Pass Basin in the highlands of Tibet . The holotype V18923 is found in the Zanda Basin on the northern edge of the Himalayas in the Zanda District, Ngari District , and thus in the far west of the Tibet Autonomous Region in the People's Republic of China . It lies at an altitude of 4114 meters and is known as IVPP ZD1001, the formation as the Zanda formation. The fossil V18924 also comes from the Zanda Basin, but from a different site (IVPP ZD1055). The third described fossil IVPP V19060, the single tooth, on the other hand, comes from the IVPP site KL0605 in the Kunlun Pass Basin in the central Kunlun Mountains.
Due to the numerous finds of vertebrate fossils, especially fish and mammals, the Zanda Basin is an important fossil deposit from the late Miocene to the early Pleistocene . Due to its location, the fauna of the area can be reconstructed and interpreted during the Pliocene period based on the fossil history. During the documented period of time the highlands of Tibet , which arose in the course of the formation of the Himalayas in the early Miocene, dried up , as well as the almost complete glaciation of the highlands at the beginning of the Pleistocene Ice Age and the associated increase in monsoon activities in India and East Asia.
Way of life and paleoecology
Vulpes qiuzhudingi probably corresponded in its way of life to the recent arctic fox. He was a predator and probably lived a large proportion of his diet on meat (hypercarnivor).
Like the arctic fox and the Tibetan fox ( V. ferrilata ) that lives in Tibet today , Vulpes qiuzhudingi was adapted to the way of life in the cold climate of the Himalayas. These adaptations include the compact physique with short ears and short legs as well as the long fur with a dense undercoat , which makes up up to 70% of the fur of the arctic fox in winter. There are also physiological adjustments such as a reduced metabolism in winter and thermoregulation via the feet, which is characterized by a fine capillary network in the ball of the toes.
“Out of Tibet” hypothesis
As early as 2011, the research team from the Chinese Academy of Sciences led by Wang from the Natural History Museum of Los Angeles County in California developed a hypothesis according to which animal species adapted to extreme cold developed in the Tibetan high mountains before the Ice Age and then over the arctic regions have spread across the northern hemisphere. The basis for this assumption, known as the “out of Tibet” hypothesis, was formed by fossils of the rhinoceros Coelodonta thibetana , which were also found on the Tibetan plateau. It was a predecessor of the woolly rhinoceros , which was widespread in the Ice Age cold steppes between Western Europe and East Asia during the Middle and Young Pleistocene . The thesis was underpinned by the first description of Vulpes qiuzhudingi and, among other things, fossils of the Panthera blytheae , an early big cat species, and the oldest fossils of the genus Sinicuon , a close relative of the red dog .
Taxonomy
Vulpes qiuzhudingi is considered by the first descriptors to be a fossil relative of the arctic fox due to its dental morphology and its adaptation to the hypercarnivorous diet and cold climates.
A convergent adaptation to cold highland climates took place in the Tibetan fox, which is regarded as a sister species of the steppe fox ( V. corsac ). This also developed as a parallel line in the Tibetan highlands.
Naming
Vulpes qiuzhudingi was named after the Chinese paleontologist Qiu Zhuding of the Chinese Academy of Sciences .
supporting documents
- ↑ a b c d e f g Xiaoming Wang, Zhijie Jack Tseng, Qiang Li, Gary T. Takeuchi, Guangpu Xie: From 'third pole' to north pole: a Himalayan origin for the arctic fox . In: Royal Society (ed.): Proceedings of the Royal Society B . 281, No. 1787, June 11, 2014. doi : 10.1098 / rspb.2014.0893 . Retrieved July 8, 2014.
- ^ A b Z. Jack Tseng, Xiaoming Wang, Graham J. Slater, Gary T. Takeuchi, Qiang Li, Juan Liu, Guangpu Xie: Himalayan fossils of the oldest known pantherine establish ancient origin of big cats. Proceedings of the Royal Society B - Biological Sciences vol. 281 no. 1774 20132686, November 2013. doi : 10.1098 / rspb.2013.2686
- ↑ Xiaoming Wang, Qiang Li, Guangpu Xie, Joel E. Saylor, Zhijie J. Tseng, Gary T. Takeuchi, Tao Deng, Yang Wang, Sukuan Hou, Juan Liu, Chunfu Zhang, Ning Wang, Feixiang Wu: Mio-Pleistocene Zanda Basin biostratigraphy and geochronology, pre-Ice Age fauna, and mammalian evolution in western Himalaya. Palaeogeography, Palaeoclimatology, Palaeoecology 374, 2013; Pp. 81-95. doi : 10.1016 / j.palaeo.2013.01.007
- ↑ 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, pp. 1285-1288. doi : 10.1126 / science.1206594
- ↑ Xiaoming Wang, Qiang Li, Guangpu Xie: Earliest record of Sinicuon in Zanda Basin, southern Tibet and implications for hypercarnivores in cold environments. Quaternary International, in Press 2014 (available online since March 2014). doi : 10.1016 / j.quaint.2014.03.028
literature
- Xiaoming Wang, Zhijie Jack Tseng, Qiang Li, Gary T. Takeuchi, Guangpu Xie: From 'third pole' to north pole: a Himalayan origin for the arctic fox . In: Royal Society (ed.): Proceedings of the Royal Society B . 281, No. 1787, June 11, 2014. doi : 10.1098 / rspb.2014.0893 . Retrieved July 8, 2014.