Pluridens serpentis, a new mosasaurid (Mosasauridae: Halisaurinae) from the Maastrichtian of Morocco and implications for mosasaur diversity

摘要: Abstract Mosasaurids (Mosasauridae) were specialized marine lizards that evolved and radiated in the Late Cretaceous. Their diversity peaked Maastrichtian, with most diverse faunas known from Morocco. Here we describe a new species of mosasaurid this fauna. Pluridens serpentis sp. nov. is described based on two complete skulls referred jaws. It to elongate robust jaws, small teeth, tooth implantation. Halisaurinae posteriorly expanded premaxilla, long premaxilla-maxilla suture, broad premaxillary facet maxilla, closed otic notch, small, striated, hooked teeth. The orbits are reduced relative other halisaurines while snout flat broad, rounded tip. jaws bear numerous hooked, snake-like Skulls imply lengths 5-6 meters; material suggests ≥10 meters. Pluridens’ morphology – especially contrasting large size teeth - distinct feeding strategy. Small P. relied nonvisual cues including touch chemoreception during foraging, as modern snakes. Numerous neurovascular foramina premaxillae consistent idea. suggest proportionately prey. dentary becomes massive largest individuals, suggesting sexual selection perhaps dimorphism, mandibles possibly functioning for combat beaked whales lizards. mosasaur emphasizes how Maastrichtian mosasaurids characterized by high richness, functional niches occupied, certain degree endemism, i.e. geographic specialization. continued diversifying until end Cretaceous, just prior K-Pg extinction.