Tokudaia Kuroda, 1943 . Biogeographica, 139:61.
TYPE SPECIES: Rattus jerdoni osimensis Abe, 1934 .
SYNONYMS: Acanthomys (Tokuda, 1941, not Lesson, 1842), Tokudamys .
COMMENTS: In addition to two species listed below, a third, yet to be named and described, occurs on Tokun-oshima Isl in the Ryukyu group (Tsuchiya, 1981; Tsuchiya et al., 1989). Best estimate of phylogenetic relationships, based on dental morphology, placed Tokudaia in a group containing Apodemus, Pliocene Rhagapodemus, and Quaternary Rhagamys; and suggested that Tokudaia evolved from Miocene Parapodemus-Apodemus ancestral stock; its evolutionary link to primitive species of Apodemus may be found in Miocene or Pliocene sediments of China (see Kawamura, 1989).