抄録
A juvenile specimen of Glossaulax hyugensis (Shuto) was collected from the Lower Pleistocene Imaizumi Sandstone and Conglomerate Member in the Nojima Formation. This formation is in the lower part of the Kazusa Group, a forearc-basin-fill sequence exposed on the Pacific Ocean side of central Japan. The specimen was found in a 9-m-thick conglomeratic sandstone bed in a channel-fill sequence. G. hyugensis is characteristic of the warm- and shallow-water Kakegawa fauna, which flourished on the Pacific Ocean side of southwestern Japan during the Late Pliocene to Early Pleistocene. The stratigraphic level at which the fossil was found is estimated to lie above the KGP tuff bed (2.5 Ma) and below the Olduvai subchronozone (1.97 Ma). This finding marks one of the latest fossil records for the species and suggests that it occurred for a long time period in the southern Kanto area, from the Late Pliocene to Early Pleistocene.
