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Mosasaurus
Meet mosasaurus—one more extraordinary life to discover.
Discover the expedition atlasA reference overview
Mosasaurus (; "lizard of the Meuse River") is the type genus (defining example) of the Mosasauridae, an extinct group of aquatic squamate reptiles. It lived from about 82 to 66 million years ago during the Campanian and Maastrichtian stages of the Late Cretaceous. The genus was one of the first Mesozoic marine reptiles known to science—the first fossils of Mosasaurus were found as skulls in a chalk quarry near the Dutch city of Maastricht in the late 18th century, and were initially thought to be crocodiles or whales.
Overview excerpt from Wikipedia contributors · Mosasaurus, under CC BY-SA 4.0. Excerpt may be shortened. Overview retrieved 2026-10-09.