Four fossil bones sat unnoticed for almost three decades, tucked inside chunks of rock that also held the remains of a mosasaur, a giant marine reptile that once ruled the world's oceans. Researchers from Okayama University of Science, Tokyo City University, and the Natural History Museum in Kishiwada City, Osaka Prefecture, made the discovery only after going back to old, unprepared rock samples collected in Kishiwada decades ago. One of the bones is a premaxilla, the tip of the upper jaw, and it is the first one ever confirmed in a mosasaur found in Japan.
