Mosasaurus

Mosasaurus is an extinct genus of large marine reptiles that lived during the Late Cretaceous. It belonged to the mosasaur family and had limbs adapted into flippers.

Mosasaur: A family of extinct marine reptiles that flourished during the Cretaceous Period. Mosasaurus is one genus within this broader family.
Mosasaur locomotion: The swimming motion and propulsion used by mosasaurs. Mosasaurus propelled itself mainly with lateral undulation of its trunk and tail.
Maastrichtian: The final age of the Cretaceous Period, spanning roughly 72 to 66 million years ago. Mosasaurus fossils are especially associated with Maastrichtian deposits.
Mosasaurus conodon: A species of Mosasaurus known from Late Cretaceous fossils in North America. It represents the genus in deposits from the western interior of North America.
Extinction: The permanent loss of a species or other taxonomic group. Recognition of the Maastricht animal helped establish that entire kinds of animals could disappear.
Squamata: The reptile order containing lizards, snakes, and their close relatives. Mosasaur ancestry places Mosasaurus among squamates rather than dinosaurs.
Mosasaur skull: The skull structure of mosasaurs, including their jaws, teeth, and sensory openings. Its skull housed the jaws and teeth used to seize prey.
Maastricht Formation: A Late Cretaceous rock formation in the Netherlands and Belgium, rich in marine fossils. The genus was named after fossils discovered near Maastricht.
Mosasaurus missouriensis: A species of Mosasaurus named from fossils found in Missouri. Its name records an early North American fossil discovery attributed to the genus.
Cretaceous–Paleogene extinction event: The mass extinction about 66 million years ago that ended the Cretaceous Period. Mosasaurus and other non-avian dinosaurs disappeared in this event.

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