長野県上田市中部中新統伊勢山層からミズウオ類口蓋骨化石の発見

抄録

A fossil palatine of alepisauroid fish was found from the lower part of the Middle Miocene (15 Ma) Iseyama Formation in Ueda City, Nagano Prefecture, central Japan. In comparison with a Recent species, this is identified as a palatine of lancetfish which belongs to the genus Alepisaurus. This is the fourth record of alepisauroid fossils in Japan and also the third one in the Northern Fossa Magna Region of Nagano Prefecture and is the largest fossil palatine of lancetfish discovered from the Japanese Miocene strata. This is probably an undescribed species of the genus Alepisaurus.