Ninjadelphis is an extinct genus of river dolphin from the early Miocene (Burdigalian) of Japan. The generic name refers to the fact that the type locality, Iga, was a training center in Japan for ninja warriors. Description Ninjadelphis is distinguished from other allodelphinids by having a trapezoidal shaped exposure of frontals on cranial vertex, a nuchal crest partly overhanging posterior end of maxilla, a wider basioccipital, and basioccipital crests widely diverging posteriorly . References Fossil taxa described in 2016 Miocene cetaceans Extinct mammals of Asia River dolphins