In the circumference of the Ôsaka region, there are widely distributed Plio-Pleistocene deposits, the Ôsaka group. In September of 1964, nearly complete, but without some limbs and tail bones, skeletons of a fossil crocodile were excavated from the upper part of the Ôsaka group, at the ground of the Ôsaka University, Machikaneyama, Shibahara, Toyonaka City, Ôsaka Pref.. The horizon was the fresh water sandy clay bed which lay between the 8th marine clay above and the 7th marine clay below, of that group. Thus, the geological age of this horizon is estimated to be the Early Pleistocene. It was the first discovery of the crocodile fossil in Japan, and then, this long snout crocodile was named as Tomistoma machikanense Kamei et Matsumoto (n. sp.).
