Sea Reptiles

New marine reptile? This skull bone matches no known mosasaur

A rock block from Japan sat in a museum for more than three decades — packed with mosasaur bones that nobody had recognised. Researchers found four overlooked bones inside it, including the first confirmed front upper-jaw bone from a mosasaur in Japan. A braincase bone bears a combination of features unlike any described mosasaur. It may represent a new species, but that has not been established.