Sulcusuchus

Sulcusuchus was first thought to be a crocodile, but scientists later realized it was a plesiosaur, a type of marine reptile.1

Its name means 'trough crocodile' because of the deep, groove-like channels on its jaw bones.1

The grooves on its snout and jaw may have held special organs that could detect electricity or movement, helping it find prey in murky water.2

One fossil of Sulcusuchus contained 95 gastroliths, or stomach stones, which may have helped it digest food or control its buoyancy.1

Sulcusuchus lived during the very end of the Age of Dinosaurs, about 69 to 66 million years ago.1

It is the only polycotylid plesiosaur from the Southern Hemisphere whose skull and lower jaw are known.2