Raoellidae

The Raoellidae, previously grouped within Helohyidae, are an extinct family of semiaquatic digitigrade artiodactyls in the clade Whippomorpha. Fossils of raoellids are found in Eocene strata of South Asia and Southeast Asia.

Raoellidae Temporal range: Early Eocene – Middle Eocene
Indohyus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Clade:	Cetaceamorpha
Family:	†Raoellidae Sahni, Bal Bhatia, Hartenberger, Jaeger, Kumar, Sudre & Vianey-Liaud, 1981
Genera
Haqueina Dehm & Oettingen-Spielberg 1958 Indohyus Rao 1971 Khirtharia Pilgrim 1940 Kunmunella Sahni & Khare 1971 Rajouria Rana et al. 2021 Raoella Sahni & Khare 1971 Metkatius Kumar & Sahni 1985

An exceptionally complete skeleton of Indohyus from Kashmir suggests that raoellids are the "missing link" sister group to whales (Cetacea). All other Artiodactyla are relatives of these two groups. δO¹⁸ values and osteosclerotic bones indicate that the raccoon-like Indohyus was habitually aquatic. However, it is still unclear if Indohyus primarily fed on land or in water. It is hypothesized that cetaceans evolved from ancestors similar to Indohyus and later fully adapted to aquatic life.

Taxonomy

• Raoella
  • Raoella dograi
• Haqueina
  • Haqueina haquei
• Indohyus
  • Indohyus indirae
  • Indohyus major
• Kunmunella
  • Kunmunella kalakotensis
  • Kunmunella transversa
• Metkatius
  • Metkatius kashmiriensis
• Khirtharia
  • Khirtharia aurea
  • Khirtharia dayi
  • Khirtharia inflatus

Sources

• Dehm, Richard; Oettingen-Spielberg, Therese zu (1958). Paläontologische und geologische Untersuchungen im Tertiär von Pakistan. 2. Die mitteleocänen Säugetiere von Ganda Kas bei Basal in Nordwest-Pakistan. Abhandlungen / Neue Folge, 91. Munich: Beck. OCLC 163296508.
• Kumar, K.; Sahni, A. (1985). "Eocene mammals from the upper Subathu Group, Kashmir Himalaya, India". Journal of Vertebrate Paleontology. 5 (2): 153–68. doi:10.1080/02724634.1985.10011853. OCLC 4649653478.
• Pilgrim, G. E. (1940). "Middle Eocene mammals from north-west Pakistan". Proceedings of the Zoological Society. B. 110. London: 127–152.
• Rao, A Ranga (1971). "New mammals from Murree (Kalakot Zone) of the Himalayan foot hills near Kalakot, Jammu and Kashmir state, India". Journal of the Geological Society of India. 12 (2): 124–34.
• Rana, R. S.; Waqas, M.; Orliac, M.; Folie, A.; Smith, T. (2021). "A new basal raoellid artiodactyl (Mammalia) from the middle Eocene Subathu Group of Rajouri District, Jammu and Kashmir, northwest Himalaya, India" (PDF). Geobios. 66–67: 193–206. Bibcode:2021Geobi..66..193R. doi:10.1016/j.geobios.2020.12.003. S2CID 233516820.
• Sahni, A.; Bhatia, S. B.; Hartenberger, J. L.; Jaeger, J. J.; Kumar, K.; Sudre, J.; Vianey-Liaud, M. (1981). "Vertebrates from the Subathu Formation and comments on the biogeography of Indian subcontinent during the early Paleogene". Bulletin of the Geological Society of France. 23 (6): 689–95. doi:10.2113/gssgfbull.S7-XXIII.6.689.
• Sahni, A. S. H. O. K.; Khare, S. K. (1971). "Three new Eocene mammals from Rajauri District, Jammu and Kashmir". Journal of the Palaeontological Society of India. 16: 41–53.
• Thewissen, JGM; Cooper, Lisa Noelle; Clementz, Mark T; Bajpai, Sunil; Tiwari, BN (20 December 2007). "Whales originated from aquatic artiodactyls in the Eocene epoch of India" (PDF). Nature. 450 (7173): 1190–4. doi:10.1038/nature06343. OCLC 264243832. PMID 18097400. S2CID 4416444. Retrieved 29 June 2013.