レター
A new fossil specimen of the Suidae (Mammalia, Artiodactyla) from the upper Miocene Oiso Formation and a brief review of Neogene suids from Japan
2022 年 128 巻 1 号 p. 287-293
詳細
2022 年 128 巻 1 号 p. 287-293
A new specimen of a fossil tooth of the Suidae (Mammalia, Artiodactyla) discovered in the upper Miocene Oiso Formation (ca. 8.29-5.57 Ma) of the Miura Group, Kanagawa Prefecture, Japan, is described. The tooth is left m3, and its hypoconulid has broken away. It is bunodont, low-crowned, and moderately to heavily worn. The m3 has the typical lower molar morphology of a medium-sized suid, with some furrows on the cusps. The part of the tooth containing the first two lobes is relatively elongated, similar to that of m3 of the Suinae. It is more elongated than that of m3 of the Asian Tetraconodontinae. Based on its size and observable morphology, this m3 is most comparable to that of Propotamochoerus hyotherioides (Suinae). This discovery reinforces the hypothesis that the Oiso Formation was deposited in the Honshu Arc, rather than the Paleo-Izu Arc. Only seven (five Miocene and two Pliocene) suid specimens have been reported from the Neogene of Japan to date.
