A new species of the genus Megapeomys (Mammalia, Rodentia, Eomyidae) from the Early Miocene of Japan

Yukimitsu Tomida

ABSTRACT

In 1998, a large, peculiar eomyid rodent Megapeomys was described from the Czech Republic. An isolated lower molar found in Japan was identified as a species of the same genus. Direct comparison of the Japanese specimen with the European material makes distinction from the Czech species possible, and therefore a new species (M. repenningi)  is described based on the characters of m1 with deeper synclinid III and single (non-splitting) distal root, in addition to a slight difference in size. The new species from Japan may represent a somewhat more primitive species, at least based on the root morphology, than Czech M. lavocati. Two apeomyine species, Megapeomys bobwilsoni and Apeomyoides savagei recently described from North America, can be distinguished from M. repenningi by clear morphological differences including size, crown height, and number of roots.

Yukimitsu Tomida. National Museum of Nature and Science, 3-23-1 Hyakunincho, Shinjukuku, Tokyo 169-0073, Japan. 

KEY WORDS: description; Eomyidae; Rodentia; Early Miocene; paleobiogeography; new species

PE Article Number: 14.3.25A
Copyright: Society of Vertebrate Paleontology November 2011
Submission: 15 June 2007. Acceptance: 17 March 2011