Orii's shrew was first described, as a subspecies of the Dsinezumi shrew (Crocidura dsinezumi orii), by Kuroda Nagamichi in 1924; he named it after his collector, Orii Hyōjirō, who had provided the skin and skull of a single male from Amami Ōshima.[2]: 3 This type specimen, damaged during the initial trapping,[2]: 3 was destroyed by fire in 1945.[4]: 22 In their 1951 checklist, Ellerman and Morrison-Scott listed the shrew instead as a subspecies of the Greater white-toothed shrew (Crocidura russula orii).[3]: 81 In 1961, after the recovery of a second individual from the stomach of a hime habu or Ryukyu Island pit viper (Ovophis okinavensis), Imaizumi Yoshinori elevated the shrew to species rank, based on morphological comparison with other species of Crocidura.[4] In 1998, after the study of five further specimens from Amami Ōshima and Tokunoshima, Motokawa Masaharu [ja] confirmed this taxonomic treatment.[5]
^Motokawa, M. (1998). "Reevaluation of the Orii's shrew, Crocidura dsinezumi orii Kuroda, 1924 (Insectivora, Soricidae) in the Ryukyu Archipelago, Japan". Mammalia. 62 (2): 249–267. doi:10.1515/mamm.1998.62.2.259.