Mosasaurs are an extinct group of large aquatic reptiles within the family Mosasauridae that lived during the Late Cretaceous. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. They belong to the order Squamata, which includes lizards and snakes.
Mosasaurus is the type genus of the mosasaurs, 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 around 1780 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.
The Mosasaurinae are a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the subfamily are informally and collectively known as "mosasaurines" and their fossils have been recovered from every continent except for South America.
Globidens is an extinct genus of mosasaurid oceanic lizard classified as part of the Globidensini tribe in the Mosasaurinae subfamily. Globidens belongs to the family Mosasauridae, which consists of several genera of predatory marine lizards of various sizes that were prevalent during the Late Cretaceous. Specimens of Globidens have been discovered in Angola, Brazil, Morocco, Syria and the United States. Among mosasaurs, Globidens is probably most well known for the highly rounded, globe-like teeth that give it its name.
Prognathodon is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Clidastes. Prognathodon has been recovered from deposits ranging in age from the Campanian to the Maastrichtian in the Middle East, Europe, New Zealand, and North America.
Clidastes is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Prognathodon. Clidastes is known from deposits ranging in age from the Coniacian to the early Campanian in the United States.
Pluridens is an extinct genus of marine lizard belonging to the Mosasauridae. Pluridens is placed in the subfamily Halisaurinae with the genera Phosphorosaurus, Eonatator and Halisaurus. Compared to related halisaurines, Pluridens had longer jaws with more teeth, and smaller eyes. It also grew large size, measuring 5–6 m (16–20 ft) long and perhaps over 9 m (30 ft) in some individuals. The jaws in some specimens are robust, and sometimes show injuries suggestive of combat. The jaws may have been used for fighting over mates or territories.
Plioplatecarpus is a genus of mosasaur lizard. Like all mosasaurs, it lived in the late Cretaceous period, about 73-68 million years ago.
Liodon is a dubious genus of mosasaur from the Late Cretaceous, known from fragmentary fossils discovered in St James' Pit, England and possibly also the Ouled Abdoun Basin of Morocco. Though dubious and of uncertain phylogenetic affinities, Liodon was historically a highly important taxon in mosasaur systematics, being one of the genera on which the family Mosasauridae was based.
Igdamanosaurus, meaning "lizard from Igdaman", is an extinct genus of Cretaceous marine lizard belonging to the mosasaur family. It is classified as part of the Globidensini tribe, and is like the other members of the tribe recognised by its rounded and knob-like teeth. These teeth indicate a highly specialized lifestyle, likely including a durophagous diet.
Wadi Harrana is a seasonal stream (wadi) in the eastern Jordanian Badia, about sixty kilometers southeast of the city of Amman. It runs eastwards from the edge of the Jordanian Highlands to the Azraq oasis.
Eremiasaurus is a genus of mosasaurs, an extinct group of marine reptiles. It lived during the Maastrichtian stage of the Late Cretaceous in what is now North Africa. Only one species is known, E. heterodontus, described in 2012 from two remarkably complete fossil specimens discovered in the Ouled Abdoun Basin, Morocco. This site is known to have delivered a significant number of other related mosasaurs.
This timeline of mosasaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of mosasaurs, a group of giant marine lizards that lived during the Late Cretaceous Epoch. Although mosasaurs went extinct millions of years before humans evolved, humans have coexisted with mosasaur fossils for millennia. Before the development of paleontology as a formal science, these remains would have been interpreted through a mythological lens. Myths about warfare between serpentine water monsters and aerial thunderbirds told by the Native Americans of the modern western United States may have been influenced by observations of mosasaur fossils and their co-occurrence with creatures like Pteranodon and Hesperornis.
The Globidensini or Globidentatini are a tribe of mosasaurine mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the tribe, known as "globidensins" or "globidensine mosasaurs", have been recovered from North America, Europe, Africa and Asia. The tribe contains the genera Globidens, Carinodens, Igdamanosaurus, Harranasaurus and Xenodens. Features of the maxilla and digits make the placement of Carinodens and Xenodens in the tribe uncertain; some researchers have suggested that they may be more appropriately placed in the Mosasaurini.
Plicatoscyllium is an extinct genus of orectolobiform shark known from deposits of Late Cretaceous age in France, Jordan, the Netherlands, Syria and the United States. Remains tentatively referrable to the genus from Cenozoic deposits have been discovered in Saudi Arabia.
Xenodens is an extinct genus of marine lizard belonging to the mosasaur family. It currently contains a single species, X. calminechari, which is known from Late Maastrichtian phosphate deposits in the Ouled Abdoun Basin, Morocco. Its closest known relative is believed to be the durophagous Carinodens.
Harranasaurus is an extinct genus of globidensin mosasaur from Jordan. The genus contains one known species, H. khuludae from the Muwaqqar Chalk Marl Formation of Jordan.
Thalassotitan is an extinct genus of large mosasaurs that lived during the late Maastrichtian of the Cretaceous period in what is now Morocco, around 67 to 66 million years ago. The only known species is T. atrox, described in 2022 from fossils discovered in the Ouled Abdoun Basin, initially identified as coming from other genera such as Mosasaurus or Prognathodon. Hypothetical Thalassotitan specimens may have been found in other corners of the world, although researchers also note the possibility that they come from distinct, related taxa. It is considered to be close to the genera Prognathodon and Gnathomortis, together forming the tribe Prognathodontini. The prognathodontines are separated from other mosasaurs based on their massive jaws and robust teeth.
