Cambaytherium

Cambaytherium is an extinct genus of placental mammals in the family Cambaytheriidae[1] whose fossils were found in an open pit coal mine located in Gujarat, India.[2] The mine was a treasure trove full of teeth and bones, over 200 of which were identified as belonging to Cambaytherium thewissi.[1] The fossils were dated to the Early Eocene, 54.5 million years ago,[3] making them slightly younger than the oldest known fossils belonging to the order Perissodactyla.

Cambaytherium
Temporal range: Eocene
Life Restoration
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Family:
Bajpai et al., 2005
Genus:
Cambaytherium[1]

Bajpai et al., 2005
Species
  • C. thewissi Bajpai et al., 2005
  • C. gracilis Smith et al., 2016
  • C. bidens Bajpai et al., 2005

Description

Cambaytherium[1] was a genus of herbivorous four-legged quadrupeds. The best-known species, C. thewissi, has been estimated to have weighed around 23 kilograms (51 lb), while the smaller C. gracilis weighed around 10 kilograms (22 lb). The remains of the third species are too fragmentary to allow a consistent estimate of its size, although it appears to have been significantly larger than the others, perhaps weighing 100 kilograms (220 lb) or more.[4] The shape and wear patterns of the teeth suggest that it was herbivorous, with a considerable amount of tough vegetation in its diet, such as nuts and abrasive leaves and stems.[5][6]

Many of Cambaytherium's features, such as the teeth and the number of sacral vertebrae, are intermediate between Perissodactyla and earlier mammals and may be indicative of what the common ancestor of all of Perissodactyla looked like.[7] The limbs have skeletal features suggesting that the animal was capable of running, but would not have been as fast as early perissodactyls. The fore-feet had at least four toes, and the hind-feet had five, one of which was vestigial, whereas even the earliest perissodactyls known had no more than four toes on each foot. The toes were short and stout, with most of the weight placed on digit three, which was slightly enlarged, as seen in living tapirs. The animal was likely at least digitigrade, and perhaps subunguligrade.[4]

Taxonomy

Cambaytherium is considered to be close to the ancestry of Perissodactyla, the odd-toed ungulates.[1][8][9] It retains features lost among the perissodactyls, a group which includes tapirs, rhinoceroses, and horses. An analysis published in 2019 placed the Cambaytheriidae as most closely related to the anthracobunids in the order Anthracobunia, a sister group to the true perissodactyls. In addition to Cambaytherium itself, the family includes Nakusia and Perissobune, which are known from more fragmentary remains.[4][10]

The presence of a sister group of perissodactyls in western India near or before the time of its collision with Asia, suggests that Perissodactyla may have originated on the Indian Plate during its final drift toward Asia.[2][11][12][13]

References

  1. ^ a b c d e f S. Bajpai; V. V. Kapur; D. P. Das; B. N. Tiwari; N. Saravanan; R. Sharma (2005). "Early Eocene land mammals from Vastan Lignite Mine, District Surat (Gujarat), Western India". Journal of the Palaeontological Society of India. 50 (1): 101–113.
  2. ^ a b Mohan, Geoffrey (20 November 2014). "Strange rhino-horse wandered ancient India". Los Angeles Times. Retrieved 21 November 2014.
  3. ^ Samanta, A.; Sarkar, A.; et al. (February 2013). "Late Paleocene–early Eocene carbon isotope stratigraphy from a near-terrestrial tropical section and antiquity of Indian mammals". Journal of Earth System Science. 122 (1): 163–171. Bibcode:2013JESS..122..163S. doi:10.1007/s12040-012-0259-6.
  4. ^ a b c d Rose, K.D.; Holbrook, L.T.; et al. (2019). "Anatomy, relationships, and paleobiology of Cambaytherium (Mammalia, Perissodactylamorpha, Anthracobunia) from the Lower Eocene of western India". Journal of Vertebrate Paleontology. 39 (sup1): 1–147. Bibcode:2019JVPal..39S...1R. doi:10.1080/02724634.2020.1761370. S2CID 226263139.
  5. ^ von Koenigswald, W.; Rose, K.D.; et al. (June 2018). "Mastication and enamel microstructure in Cambaytherium, a perissodactyl-like ungulate from the early Eocene of India". PalZ. 92 (4): 671–680. Bibcode:2018PalZ...92..671V. doi:10.1007/s12542-018-0422-8. S2CID 133969194.
  6. ^ "Out of India - 11/20/2014". www.hopkinsmedicine.org. Retrieved 2023-01-05.
  7. ^ von Koenigswald, Wighart; Rose, Kenneth D.; Holbrook, Luke T.; Kumar, Kishor; Rana, Rajendra S.; Smith, Thierry (2018-12-01). "Mastication and enamel microstructure in Cambaytherium, a perissodactyl-like ungulate from the early Eocene of India". PalZ. 92 (4): 671–680. Bibcode:2018PalZ...92..671V. doi:10.1007/s12542-018-0422-8. ISSN 1867-6812. S2CID 133969194.
  8. ^ Rose, K. D.; Holbrook, L. T.; Rana, R. S.; Kumar, K.; Jones, K. E.; Ahrens, H. E.; Missiaen, P.; Sahni, A.; Smith, T. (20 November 2014). "Early Eocene fossils suggest that the mammalian order Perissodactyla originated in India". Nature Communications. 5 (5570): 5570. Bibcode:2014NatCo...5.5570R. doi:10.1038/ncomms6570. hdl:1854/LU-5972511. PMID 25410701.
  9. ^ rpantaleo (25 November 2014). "Common Ancestor of Today's Horse and Rhino Found in India – Science World". VOA. Retrieved 2023-01-05.
  10. ^ Missiaen, Pieter; Rose, Kenneth; Ahrens, Heather; Kumar, Kishor; Smith, Thierry (2011). "Revision of Indobune and Cambaytherium from the early Eocene of Vastan (India), and their affinities with anthracobunid and perissodactyl mammals". Journal of Vertebrate Paleontology. 31. hdl:1854/LU-3178728.
  11. ^ Wesson, Simon (2020-11-02). "Indian fossils support new hypothesis for origin of hoofed mammals". Taylor & Francis Newsroom. Retrieved 2023-01-05.
  12. ^ Rose, Kenneth D.; Holbrook, Luke T.; Kumar, Kishor; Rana, Rajendra S.; Ahrens, Heather E.; Dunn, Rachel H.; Folie, Annelise; Jones, Katrina E.; Smith, Thierry (2019-11-11). "Anatomy, Relationships, and Paleobiology of Cambaytherium (Mammalia, Perissodactylamorpha, Anthracobunia) from the lower Eocene of western India". Journal of Vertebrate Paleontology. 39 (sup1): 1–147. Bibcode:2019JVPal..39S...1R. doi:10.1080/02724634.2020.1761370. ISSN 0272-4634. S2CID 226263139.
  13. ^ Rose, Kenneth D.; Holbrook, Luke T.; Rana, Rajendra S.; Kumar, Kishor; Jones, Katrina E.; Ahrens, Heather E.; Missiaen, Pieter; Sahni, Ashok; Smith, Thierry (2014-11-20). "Early Eocene fossils suggest that the mammalian order Perissodactyla originated in India". Nature Communications. 5 (1): 5570. Bibcode:2014NatCo...5.5570R. doi:10.1038/ncomms6570. hdl:1854/LU-5972511. ISSN 2041-1723. PMID 25410701.