1. An extinct marine reptile of the Late Cretaceous period, related to modern lizards and snakes, characterized by a long body (up to 17 meters), powerful jaws, and flipper-like limbs
   "Fossils of mosasaurs have been found on every continent";
   - mosasaurus
    
2. (palaeontology) any member of the family Mosasauridae, a group of large, predatory, aquatic lizards that lived during the Late Cretaceous period, approximately 82 to 66 million years ago
   "The discovery of a new mosasaur species excited the paleontological community"

Derived forms: mosasaurs

Encyclopedia: Mosasaur