HANOMYS MALCOLMI, A NEW SIMPLICIDENTATE MAMMAL FROM THE PALEOCENE OF CENTRAL CHINA: ITS RELATIONSHIPS AND STRATIGRAPHIC IMPLICATIONS

Abstract A simplicidentate mammal, Hanomys malcolmi, new genus and species, is the only fossil currently known from a recently discovered, presumably Paleocene, locality near Danjiangkou, Hubei Province, China. The specimen consists of the anterior part of a skull with complete dentition and articulated lower jaw, lacking only P3. Hanomys resembles the mixodont simplicidentates Heomys and Eurymylus in dental formula and general morphology of the cheek teeth. It differs from them in a combination of characters such as a more expanded hypocone on P4–M2 and dorsoventral expansion of the anterior root of the zygomatic arch. These characters indicate that Hanomys is at the root of the clade that includes Rhombomylus and Matutinia. This clade, a short-lived lineage known only from Asia, is here recognized as the family Rhombomylidae.

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