Overview

Mosasaurus is the type genus 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. One skull discovered in 1778 was famously nicknamed the "great animal of Maastricht". In 1808, naturalist Georges Cuvier concluded that it belonged to a giant marine lizard with similarities to monitor lizards but otherwise unlike any known living animal. This concept was revolutionary at the time and helped support the then-developing ideas of extinction. Cuvier did not designate a scientific name for the animal; this was done by William Daniel Conybeare in 1822 when he named it Mosasaurus in reference to its origin in fossil deposits near the Meuse River. The exact affinities of Mosasaurus as a squamate remain controversial, and scientists continue to debate whether its closest living relatives are monitor lizards or snakes.

Source: Wikipedia

When it lived

100.5 – 61.7 million years ago · Cenomanian to Danian · Cretaceous, Paleogene

Where it was found

Netherlands, Belgium, North America · Countries with fossils: AO, AQ, AR, BE, BG, BR, CA, CD, CU, DE, DK, ES, FR, IT, JO, JP, MA, MX, NE, NL, NZ, PL, RU, SE, SY, TR, UK, US, ZA

130 fossil occurrences in the Paleobiology Database · Rock formations: Argille Varicolori, Argille di Viano, Bearpaw Shale, Cantabria, Conway, Conway , Couche III, Craie de Ciply

Size

02468101214

Length 14 m · Mass 10 t · Size estimates are editorial, from the literature; silhouettes from PhyloPic.

Length

14 m

Height

1.5 m

Mass

10 t10,000 kg

First appearance

100.5 MaCenomanian

Last appearance

61.7 MaDanian

Span of the fossil record

38.8 million years

Fossil occurrences

130AO, AQ, AR, BE, BG, BR, CA, CD, CU, DE, DK, ES, FR, IT, JO, JP, MA, MX, NE, NL, NZ, PL, RU, SE, SY, TR, UK, US, ZA

Year named

1822Parkinson

Sources