Mosasaur - Natural minerals and crystals

Mosasaurs are an extinct family of marine reptiles close to lizards and snakes but unrelated to dinosaurs. They appear in the Lower Cretaceous and disappear at the same time as the dinosaurs during the Cretaceous-Tertiary extinction, about 66 million years ago. Mosasaurs were adapted to marine life but like modern whales breathed in the open air. They could be up to 18 meters long and weigh more than 15 tons.