Mosasaurus
Mosasaurus ("lizard of the Meuse River") was a genus of mosasaur, a carnivorous, aquatic lizard, somewhat resembling a flippered crocodile, with elongated heavy jaws. The genus lived in the Maastrichtian age of the Cretaceous period (Mesozoic era), around 70-65 millions years ago. The name means "Meuse lizard", as it was found near the Meuse River (Latin Mosa + Greek sauros lizard). As with most mosasaurs, their legs and feet are modified into hydrofoil-like flippers, with the forelimbs larger than the hindlimbs. The first mosasaur ever discovered, Mosasaurus hoffmannii, was excavated in a mine near Maastricht, the Netherlands in the 1770s. Like its relatives Tylosaurus and Hainosaurus, Mosasaurus reached lengths of about 15meters.