Abstract
Amynthas japonicus (Horst, 1883) was one of three native earthworms first described from Japan in Dr P.F.B. von Siebold’s collection from around 1820s (Edo period). While the other two species are relatively well known and their current distributions mapped, the species of concern has not been found since. An expedition organized to collect earthworms from the probable Nagasaki type-locality failed to find this worm. This, coupled with review of surveys by other workers, shows that this species has not been recorded for nearly 200 years and is either particularly rare or, more likely, extinct. Its current IUCN Redlisting as Data Deficient but “Possibly extinct” should now be reclassified as “Extinct”. This is the first earthworm and second invertebrate extinction from Japan. An updated checklist of known Japanese native earthworms is appended.
