History of commensal rodents on Ishigaki Island (southern Ryukyus) reconstructed from Holocene fossils, including the first reliable fossil record of the house mouse Mus musculus in Japan

摘要

The history of commensal rodents in mainland Japan and the Ryukyu Islands (Ryukyus) has been poorly understood owing to the paucity of reliable fossil records. Recent excavation of the Shiraho-Saonetabaru cave site on Ishigaki Island of the southern Ryukyus yielded a large number of rodent fossils from well-dated sediments ranging from the Late Pleistocene to the Holocene. Some of the fossils were preliminarily assigned to Mus musculus and Rattus sp. They are described here to confirm their taxonomic positions. These forms are considered to be commensal rodents.