Eggysodontidae or Eggysodontinae is an extinct family or subfamily of rhinocerotoids. Fossils have been found in Oligocene deposits in Europe, the Caucasus, Central Asia, China, and Mongolia.
Taxonomy Eggysodonts are traditionally considered a subfamily of the rhinocerotoid famly Hyracodontidae, as Eggysodontinae.Radinsky, L. B., 1967. The families of the Rhinocerotoidea (Mammalia, Perissodactyla). J Mammal 47, 631–639.Uhlig U 1999. Die Rhinocerotoidea (Mammalia) aus der unteroligozänen Spaltenfüllung Möhren 13 bei Treuchtlingen in Bayern. Abhandlungen der Bayerischen Akademie der Wissenschafen, Mathematisch-Naturwissenschaftliche Klasse, Neue Folge, Munich 170: 1–254.Qiu Zhan-xiang; Wang Ban-yue, 1999. Allacerops (Rhinocerotoidea, Perissodactyla) its discovery in China and its systematic position. Vertebrata PalAsiatica 37 (1): 48-61, pl.1Heissig, K., 1989. Rhinocerotidae. In D. R. Prothero and R. M. Schoch, (eds.), The evolution of perissodactyls, pp.399-417. New York: Oxford Univ. Press. Rhinocerotoid phylogeny is highly variable between analyses. Some recent analyses recover eggysodonts as outside of Hyracodontidae, which has led to some researchers recognizing them as a distinct family, Eggysodontidae.Haibing Wang; Bin Bai; Jin Meng; Yuanqing Wang (2016). "Earliest known unequivocal rhinocerotoid sheds new light on the origin of Giant Rhinos and phylogeny of early rhinocerotoids". Scientific Reports. 6: Article number 39607. doi:10.1038/srep39607.Z. Qiu and B. Wang. 2007. Paracerathere Fossils of China. Palaeontologia Sinica, New Series C 193(29):1-396B. Bai and Y.-Q. Wang. 2012. Proeggysodon gen. nov., a primitive Eocene eggysodontine (Mammalia, Perissodactyla) from Erden Obo, Siziwangqi, Nei Mongol, China. Vertebrata PalAsiatica 50(3):204-218 They have been recovered in a variety of different positions in the rhinocerotoid family tree. Some analyses still recover eggysodonts within a monophyletic Hyracodontidae, in which case they are still treated as a subfamily.
Biology Eggysodonts were small, ground-dwelling browsers.
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