Shundong Bi, Jin Meng, Wenyu Wu, Jie Ye, Xijun Ni
American Museum Novitates 2009 (3663), 1-18, (28 August 2009) https://doi.org/10.1206/665.1
Three new distylomyid species, Distylomys burqinensis, Prodistylomys wangae, and P. lii, are described from the Suosuoquan Formation, early Miocene, of Xinjiang Province, northwestern China. Previously unknown cranial materials and upper dentitions add new information for the higher-level taxonomy of distylomyid rodents. Based on these new discoveries, the Family Distylomyidae is resurrected. These fossils demonstrate that distylomyids have a combination of primitive “ctenodactylid” characters and derived hystricognathous ones, possibly indicating a close affinity with South American caviomorph rodents and thereby offering new evidence to challenge the hypothesis that the traditional “Ctenodactyloidea” are monophyletic.
Prodistylomys lii was recovered from Suosuoquan mammal assemblage III (magnetostratigraphically dated as 21.69–21.16 Mya) at the Chibaerwoyi locality. Distylomys burqinensis and Prodistylomys wangae were collected from a new fossiliferous locality, Locality XJ200601 of Burqin County. The composition of the fauna from this new locality suggests that it represents an assemblage younger than Suosuoquan mammal assemblage III. Preliminary comparison with other faunas suggests that the assemblage is of early Miocene age, approximately 20 Mya old, and is a new fossil level within the Suosuoquan Formation.