Early Miocene Platanistoid from the Mizunami Group, Central Japan

A platanistoid fossil was recovered from the upper Lower Miocene Akeyo Formation, Mizunami Group, Gifu Prefecture, Japan. It consists of a right scapula, two cervical and three thoracic vertebrae, and an isolated tooth. The following key apomorphies of Platanistoidea are found in the scapula of the specimen: loss of or greatly reduced coracoids process, acromion located on the anterior edge of the scapula, and disappearance of the supraspinatus fossa on the lateral side of the scapula. This is the fourth platanistoid to be reported from Japan.