This study presents a compilation of fossil and archeological records of the Ryukyu long-furred rat Diplothrix legata, a murid rodent endemic to the central part of the Ryukyu Archipelago (Amami and Okinawa Islands) of Japan, in order to further understand the distributional history of this endangered species. Although the species is currently confined to restricted forest areas on three islands (Amamioshima, Tokunoshima, and Okinawajima), fossiles or archeological occurrences have been reported at several extralimital localities on these islands, as well as on three other islands (Okinoerabujima, Kumejima, and Miyagijima). The records from the small island of Miyagijima are most likely remains from animals artificially brought to the island. The southern part of Okinawajima is devoid of Holocene records of the species during and after the Gusuku Period (from the 11th to 15th centuries Current Era [CE]) except for a single case. The species' decline in this area has been attributed to human activity in the Gusuku Period.