We’re going to need a bigger boat: palaeontologists including UC Davis postdoc Lars Schmitz have described a 30-foot long ichthyosaur — an air-breathing, dolphin-like marine reptile — with five-inch long razor teeth that was likely the top predator in the ocean 244 million years ago. The fossil is described in a paper published in Proceedings of the National Academy of Sciences Jan. 7.

The fossil was found during a dig in Nevada, well-known as a site for ichthyosaur fossils. The researchers named the beast Thalattoarchon saurophagis, or “lizard-eating ruler of the seas,” because it likely preyed on other marine reptiles, filling the role of top predator of its time, like a modern Great White shark or killer whale.

T. saurophagi appeared just eight million years after the mass extinction at the end of the Permian era, when most life at sea was wiped out. The fossil find shows that marine life evolved rapidly after the Permian extinction, the researchers argue in their paper. Reptiles had colonized the ocean from land just four million years earlier.

“It was the first giant air-breathing marine predator equipped with teeth with cutting edges,” Ryosuke Motani, a UC Davis paleobiologist and ichthyosaur expert who was not involved in the discovery, told Wired.com.

Field Museum scientist Jim Holstein first discovered the fossil in 1997 returning tired from a day of fossil hunting. However, the complete fossil was not excavated until 2008, after Schmitz and Nada Frobisch stumbled over Holstein’s notes and realized the significance of the find. An expedition to collect the fossil was sponsored by the National Geographic Society.

More information: Ryosuke Motani’s Wonderful world of ichthyosaurs page