EVOLUTION OF CHINESE CASTORIDAE
This research investigates the origin and relationships among Chinese fossil beavers. Chinese beavers belong to nine species in seven genera (Youngofiber sinensis, Anchitheriomys tungurensis, Trogontherium cuvieri, Eucastor youngi, Dipoides majori, Dipoides anatolicus, Steneofiber hesperus, Castor anderssoni, and Castor zdanskyi), ranging in age from the Miocene to Pleistocene. The fossil record in China does not represent a continuum in castorid evolution but results from southward dispersals from the northern Asian corridor fauna. There are five immigration events since the Miocene : around 20Ma for Steneofiber hesperus and the appearance of Youngofiber; 14-13Ma for Anchitheriomys tungurensi; 7-6Ma for Dipoides and Castor; 4-3.5Ma for Eucastor; 2.5Ma for Trogontherium. Sinocastor is a synonym of Castor. Youngofiber from China and Japan, Asiacastor from Kazakhstan, Anchitheriomys from northern continents, and Trogontherium from Eurasia form a monophyletic group. This group is a sister taxon of the North American giant beaver group (including Eucastor and Dipoides). Steneofiber and Castor represent a third clade having a remote relationship to the foregoing clades.
- National Science Museum monographs
National Science Museum monographs 8, 77-97, 1994