Eremiasaurus

Eremiasaurus ("desert lizard") is a genus of mosasaurs, an extinct group of marine reptiles, who lived during the Maastrichtian stage of the Late Cretaceous. The first known fossils of this taxon were teeth discovered in the Ouled Abdoun Basin in Morocco, and described in 1952 by Camille Arambourg as coming from Mosasaurus. However, it was in 2012 that Aaron R. H. LeBlanc and his colleagues described the only known species, E. heterodontus, from two more or less complete skeletons that had been discovered in the same geological area as the teeth originally described by Arambourg. Subsequently, fossil teeth discovered in Israel, Brazil, and the Ganntour Basin in Morocco were subsequently attributed to the genus.

It is a relatively small mosasaurid, with the syntype specimens suggesting a size of around 5 m (16 ft) long. The animal's skull is robust and is characterized by its very pronounced heterodonty (hence its specific epithet), a trait rarely observed in others mosasaurs. This particular dentition leaves it unclear what prey the animal consumed. The anatomy of the caudal vertebrae of Eremiasaurus suggests that it would have been a predator capable of swimming at high speed. Eremiasaurus lived in the southern margin of the Mediterranean Tethys. This paleo-ocean had a significant diversity of aquatic vertebrates and had a temperate and warm oceanic climate. The fossil record also shows that there would have been niche partitioning between Eremiasaurus and the various other mosasaur species identified within the Ouled Abdoun Basin.