King of the ancient seas

Bus-sized marine reptile had teeth with serrated edges

BRISTOL, England — Paleontologists have unearthed the nearly complete remains of an immense ichthyosaur with serrated teeth, an evolutionary innovation that would have rendered the behemoth the top predator in its ecosystem.

The newly described marine creature, whose remains were discovered at a remote site in central Nevada, lived about 240 million years ago, at a time early in ichthyosaur evolution, Nadia Fröbisch reported September 23 at the Society of Vertebrate Paleontology annual meeting.