Amynodontidae Explained

Amynodontidae ("defensive tooth")^{[1] [2]} is a family of extinct perissodactyls related to true rhinoceroses. They are commonly portrayed as semiaquatic hippo-like rhinos^{[3] [4]} but this description only fits members of the Metamynodontini; other groups of amynodonts like the cadurcodontines had more typical ungulate proportions and convergently evolved a tapir-like proboscis.

The Greek name of the family describes their tusks, derived from enlarged canine teeth. Odd-toed ungulates are herbivores, so these tusks would have been used either to deter or defend against predators (as suggested by the name) or perhaps in fights among males.^[5]

Their fossils have been found in North America, and Eurasia ranging in age from the Middle Eocene to the Early Oligocene, with a single genus (Cadurcotherium) surviving into the Late Oligocene in South Asia (Pakistan).^[6] The genus Metamynodon may have survived into the early Miocene.

Taxonomy

†Amynodontidae

• Subfamily Amynodontinae
  • Tribe Cadurcodontini
    • Genus Cadurcodon^[7]
    • Genus Lushiamynodon^[7]
    • Genus Sharamynodon^[7]
  • Tribe Metamynodontini
    • Genus Gigantamynodon^[7]
    • Genus Metamynodon
    • Genus Paramynodon^[7]
    • Genus Zaisanamynodon^[7]
  • Tribe incertae sedis
    • Genus Amynodon^[7]
• Subfamily incertae sedis
  • Genus Amynodontopsis^[7]
  • Genus Armania^[8]
  • Genus Cadurcotherium^[7]
  • Genus Caenolophus^[9]
  • Genus Hypsamynodon^[7]
  • Genus Megalamynodon^[7]
  • Genus Penetrigonias^[10]
  • Genus Procadurcodon^[7]
  • Genus Rostriamynodon^[11]
  • Genus Teilhardia^[11]

Notes and References

1. Web site: Glossary | Perissodactyl. research.amnh.org. 29 June 2023.
2. https://logeion.uchicago.edu/%E1%BC%80%CE%BC%CF%8D%CE%BD%CF%89
3. Book: Savage, RJG . Long, MR . 1986 . Mammal Evolution: an illustrated guide. registration . Facts on File. New York. 194. 0-8160-1194-X.
4. Book: Palmer, D.. 1999 . The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. Marshall Editions. London. 264. 1-84028-152-9.
5. Web site: Horns, Tusks, and Flippers: The Evolution of Hoofed Mammals . rhinoresourcecenter.com. 29 June 2023.
6. Book: Wall. William P.. Prothero. Donald R.. Schoch. Robert M.. The Evolution of perissodactyls. 1989. Oxford University Press. 9780195060393. The phylogenetic history and adaptive radiation of the Amynodontidae.
7. Averianov . A. . Danilov . I. . 89118812 . etal . 2017 . A new amynodontid from the Eocene of South China and phylogeny of Amynodontidae (Perissodactyla: Rhinocerotoidea) . Journal of Systematic Palaeontology . 15 . 11 . 927–945 . 10.1080/14772019.2016.1256914. 2017JSPal..15..927A .
8. von Koenigswald . W. . Holbrook . L.T. . 33679289 . etal . March 2011 . Diversity and Evolution of Hunter-Schreger Band Configuration in Tooth Enamel of Perissodactyl Mammals . Acta Palaeontologica Polonica . 56 . 1 . 11–32 . 10.4202/app.2010.0021. free .
9. Huang . X. . Wang . J. . January 2001 . New materials of tapiroid and rhinocerotoid remains (Mammalia, Perissodactyla) from the Middle Eocene of Yuanqu Basin, Central China . Vertebrata PalAsiatica . 39 . 3 . 197–203 . 14 August 2020.
10. Antoine . P. . Ducrocq . S. . etal . 2003 . Early rhinocerotids (Mammalia: Perissodactyla) from South Asia and a review of the Holarctic Paleogene rhinocerotid record . Canadian Journal of Earth Sciences . 40 . 3 . 365–374 . 10.1139/e02-101. 2003CaJES..40..365A .
11. Wall . W.P. . Manning . E. . July 1986 . Rostriamynodon grangeri n. gen., n. sp. of amynodontid (Perissodactyla, Rhinocerotoidea) with comments on the phylogenetic history of Eocene Amynodontidae. Journal of Paleontology . 60 . 4 . 911–919 . 10.1017/S0022336000043079 . 1305081 . 1986JPal...60..911W . 59363111 .