Ischyromyid rodents found from the Eocene of Erlian Basin in Nei Mongol
The ischyromyids are the most primitive rodents that have a Holarctic Paleogene distribution. Members of the family are predominant in Paleogene rodents of North America, but are relatively rare in both Asia and Europe. In a study published in the latest issue of Vertebrata PalAsiatica 51(4), Drs. LI Qian and MENG Jin, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), Chinese Academy of Sciences, reported some new findings of the Eocene ischyromyids from the Huheboerhe area in the Erlian Basin, Nei Mongol, China. These include Asiomys dawsoni from the basal strata of the Irdin Manha Formation and Ischyromyidae gen. et sp. indet. from the basal strata of the Arshanto Formation. The new materials include fragmentary mandibles and numerous cheek teeth, which provide new evidence for the mammal's dispersal between Asia and North America during the Middle Eocene.