Mosasaurus Fact Sheet

General

Mosasaurus, meaning “lizard of the Meuse River (Maas)”, was actually not a dinosaur. Dinosaurs are extinct animals with upright limbs that lived on land during the Mesozoic Era (252 to 66 million years ago). Mosasaurus was a separate group of aquatic reptiles, more closely related to modern snakes and lizards. They lived from about 82 to 66 million years ago during the Late Cretaceous.

Traditional interpretations have estimated the maximum length of the largest species, M. hoffmannii, to be up to 17.1 meters (56 ft), making it one of the largest mosasaurs, although some scientists consider this an overestimation with recent estimates suggesting a length closer to 13 meters (43 ft). The skull of Mosasaurus was equipped with robust jaws capable of swinging back and forth and strong muscles capable of powerful bites using dozens of large teeth adapted for cutting prey. Its four limbs were shaped into robust paddles to steer the animal underwater. Its tail was long and ended in a downward bend and a paddle-like fluke.

Dicovery

The earliest fossils of Mosasaurus known to science were found as skulls in a chalk quarry near the Dutch city of Maastricht in the late 18th century. At first the discoverers claimed the bones to be originated from ancient crocodiles or whales. One skull discovered around 1780, and which was seized by France during the French Revolutionary Wars for its scientific value, was famously nicknamed the “great animal of Maastricht”.

Habitat and lifestyle

Known fossils of Mosasaurus have typically been recovered from deposits representing nearshore habitats during the Cretaceous period, with some fossils coming from deeper-water deposits. Mosasaurus lived alongside other large predatory mosasaurs also considered apex predators, most prominent among them being the tylosaurines and Prognathodon.

Pop culture references

Mosasaurus was made famous by movies like Jurassic World were it jumped out of the water to catch its prey. The actual size of a Mosasaurus was a lot smaller. In Aquaman, the mermen rode Mosasaurus-like creatures in the final battle.