市道戸狩・月吉線工事現場（瑞浪市明世町）の下部中新統瑞浪層群明世層より鰭脚類の頭蓋を含む骨格化石の産出

抄録

A pinniped fossil was found at the construction site of the Togari-Tsukiyoshi City Road in Akeyo-cho, Mizunami City, Gifu Prefecture, Japan in September 2020. We briefly report this new discovery of a partial skeletal bones belonging to a single individual (MFM18009), which was recovered from the lowermost part of the Yamanouchi Member of the Akeyo Formation, the Mizunami Group (lower Miocene: ca 18 Ma). MFM18009 is consisted from a complete skull, distal half of the left mandible, the atlas, distal half of the left humerus, proximal half of the left ulna, the third metacarpus, thoracic vertebrae and ribs. MFM18009 seems to belong in the Pteronarctos-Pacificotaria species complex of pinnipediforms, and is provisionally identified as Enaliarctine genus and species undetermined.