Abstract
Part of a right dentary of a pseudodontorn, bony-toothed bird, was newly found from the shell bed of the Kamimitsugano tuffaceous siltstone Facies of the Mitsugano Member in the Oi Formation (17.5-17 Ma), Ichishi Group in the Misato area, Mie Pref., Central Japan. This is the first record of a pseudodontorn bill from the Miocene of Japan. The discovery supplements the fossil record of pseudodontorns in Japan, which comprises the Early Oligocene to the Pliocene. The arrangement of the bony teeth corresponds to that of Osteodontornis orri Howard, 1957 known from the west coast of North America, and the specimen is provisionally identified as Osteodontornis sp.