Mosasaur (Primeval)

Mosasaurs were serpentine marine reptiles and ferocious predators from the Cretaceous period.

Characteristics
Mosasaurs were large serpentine marine reptiles and aquatic predators; They were not dinosaurs, but evolved from semi-aquatic squamates known as the "aigialosaurs", close relatives of modern-day monitor lizards. Mosasaurs breathed air, and were powerful swimmers that were well-adapted to living in the warm, shallow epicontinental seas prevalent during the Late Cretaceous. They grew up to 20 metres long but juveniles averaged 6-7 metres.

The species encountered by the Home Office possessed crocodilian-like armour, a long serpentine-like body, and they attacked aquatic animals for food, but would also attack creatures that were above the surface. These Mosasaurs would also attack and eat smaller Mosasaurs as well as other aquatic creatures.