We live in a geometric world. From the rectangular skylines of our cities and the orbiting planets of our solar system to the symmetry of butterfly wings and the spiraling double helix of DNA, every shape has its place. 

For as long as he can remember, Ryosuke Motani has been fascinated by shapes. And he’s built an illustrious paleobiology career studying them.

Some 240 million years ago, a dolphin-like ichthyosaur ripped to pieces and swallowed another marine reptile only a little smaller than itself. Then it almost immediately died and was fossilized, preserving the first evidence of megapredation, or a large animal preying on another large animal. The fossil, discovered in 2010 in southwestern China, is described in a paper published Aug. 20 in the journal iScience.