The Mosasaurs with the extinction of the ichthyosaurs and pliosaurs became the dominant marine predators of the age. The Cretaceous period marine reptile featured in the saga of Jurassic world films. The Mosasaurs were a group of perfectly developed marine predators, resembling a crocodilian and lizard form, with gigantic double-hinged jaws, with an artillery of large teeth, fully equipped to tackle the once prehistoric and deadly oceans. Yet to be proven however it is believed the Mosasaurus family were able to unhinge their jaws for a more precise attack and with a much deadlier force.
At first, it was thought that Mosasaurs used their bodies like snakes or eels when swimming, in an undulating side to side movement. However, the most recent research leads experts to theorise the Mosasuaurus species anatomy remained quite still whilst their large tail with tremendous strength and power provided the locomotion to propelled them forward.
Part of a more ancient group of aquatic lizards, the aigialosaurs group. Mosasaurs breathed air, gave birth to live young and grew from around 3 feet; Dallasaurus turneri, the smallest Mosasaur to 50 feet in length; Mosasaurus hoffmannii, the largest. The Mosasaurs reigned for around 20 million years before the mass extinction which also ended the dinosaurs' existence, around 65 million years ago at the K-T boundary event. This was the last 20 million years of the Cretaceous period. The Turonian to Maastrichtian ages.
The first fossils were discovered in an 18th-century limestone quarry near Maastricht on the river Meuse. When first discovered the skeleton was thought to be that of a dragon and the major of Maastricht had the fossil bones put on display in a glass case for all to marvel at the size of the amazing new discovery.