A museum rock was forgotten for 30 years in a drawer in Japan. Now, its hidden bones may uncover a new 66-million-year-old sea monster

Researchers in Japan have identified four previously overlooked mosasaur bones from rock samples collected in the early 1990s. One bone is the first confirmed mosasaur premaxilla found in Japan, while unusual features in another skull bone suggest the fossil may belong to a previously unknown species.