SelmasaurusSelmasaurus is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Plioplatecarpinae subfamily alongside genera like Angolasaurus and Platecarpus. Two species are known, S. russelli and S. johnsoni; both are exclusively known from Santonian deposits in the United States. Selmasaurus is unique among the mosasaurs in that its skull is unusually akinetic, meaning that it is incapable of widening to swallow larger prey.
PlioplatecarpinaePlioplatecarpinae is a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the subfamily are informally and collectively known as "plioplatecarpines" and have been recovered from all continents, though the occurrences in Australia remain questionable. The subfamily includes the genera Latoplatecarpus, Platecarpus, Plioplatecarpus and Plesioplatecarpus. Plioplatecarpines were small to medium-sized mosasaurs that were comparatively fast and agile compared to mosasaurs of other subfamilies.
PrognathodonPrognathodon 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. Prognathodon means "forejaw tooth", which originates from the Latin pro- ("earlier" or "prior"), Greek gnathos ("jaw") and odṓn ("tooth").
MosasaurMosasaurs (from Latin Mosa meaning the 'Meuse', and Greek σαύρος sauros meaning 'lizard') comprise a group of extinct, large marine reptiles from 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. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Earliest Late Cretaceous with 42 described genera.