Raoellidae
| Raoellidae | ||||||||||||
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Graphic representation of Indohyus |
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| Temporal occurrence | ||||||||||||
| Middle Eocene | ||||||||||||
| 50 to 48 million years | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Raoellidae | ||||||||||||
| Sahni , Bal Bhatia , Hartenberger , Jaeger , Kumar , Sudre & Vianey-Liaud , 1981 | ||||||||||||
The Raoellidae are an extinct group of even-toed ungulates that lived on the Indian subcontinent in the mid Eocene . Fossils have been found in Jammu and Kashmir and in the northern Pakistani Kala Chitta Mountains. At this time the Indian subcontinent had no contact with Asia and was isolated as an island continent in the Indian Ocean . A find of uncertain assignment to the Raoellidae is also from Burma .
The mammalian family was founded in 1981 by Sahni et al. set up. Type is the genus Raoella , which is now considered a synonym of Indohyus . The genera placed in the Raoellidae belonged to the Dichobundidae , the Helohyidae or were assigned to the pig-like species (Suiformes) incertae sedis . The family is documented in fossil form mainly through tooth finds.
Systematics
In December 2007, Hans Thewissen et al. in the journal Nature that an unusually complete skeleton of Indohyus from Kashmir suggests that the Raoellidae were aquatic and must be considered a sister group of the whales (Cetacea). In particular, the morphology of the ears and premolars , the density of the leg bones and the isotopic composition of the teeth show a close relationship between Indohyus and whales.
Genera
- Khirtharia Pilgrim, 1940
- Indohyus Ranga Rao, 1971
- Kunmunella , Sahni & Khare, 1971
- Metkatius , Kumar & Sahni, 1985
The genera can be divided into two groups: Khirtharia and Metkatius were small and had bunodonte or slightly lophodonte teeth. Indohyus and Kunmunella grew larger and had clearly lophodontic teeth.
literature
- Donald R. Prothero, Scott E. Foss (Eds.): The Evolution of Artiodactyls. Johns Hopkins University Press, Baltimore MD 2007, ISBN 978-0-8018-8735-2 .
Web links
Individual evidence
- ↑ JGM Thewissen, Lisa Noelle Cooper, Mark T. Clementz, Sunil Bajpai, BN Tiwari: Whales originated from aquatic artiodactyls in the Eocene epoch of India . In: Nature . tape 450 , December 20, 2007, pp. 1190–1194 , doi : 10.1038 / nature06343 .