Mosasaurs are extinct aquatic reptiles that stalked the Cretaceous oceans 140 to 66 million years ago.

The largest species, M. hoffmannii, could get over 44 feet long while the smallest was only 3 feet long. Fossils of this marine predator are found in Africa, Asia, North and South America, and even Antarctica.

Their conical skulls had strong jaws lined with dozens of sharp teeth. Like snakes, the jaws could expand with a second set of teeth in the back to help swallow food. It had 4 paddle-shaped limbs and a downturned tail.

Mosasaurs ate anything they could find like sharks, birds, cephalopods (squid, ammonites), fish, and even other mosasaurs. Because they were reptiles, mosasaurs had to surface to breathe air.

Type: Mosasaurus Tooth
Group: Plesiosaures
Family: Mosasaurides
Age: Upper Cretaceous (80-65 million years ago)
Khouribga, Morocco

Size of Matrix: 2.38 x 1.63 x 1.63 inches
Size of Specimen: 1.44 x .94 x .75 inches
Weight: 3.15 oz.