Mosasaur Tooth and Plesiosaur Tooth in Matrix | Morocco

Mosasaur (Prognathodon sp.) and Plesiosaur (Zarafasaura oceanis)
Late Cretaceous (~70 million years ago)
Phosphate Deposits
Oulad Abdoun Basin, Morocco

Mosasaur tooth approx. size: 2"

Plesiosaur tooth approx. size: 1.75"

Matrix approx. size: 3.5" x 3" x 1.5"

Prognathodon was a large, formidable marine reptile belonging to the mosasaurs—a group of ocean-dwelling predators that thrived during the Late Cretaceous period, roughly 100 to 66 million years ago. Unlike dinosaurs, mosasaurs were more closely related to modern monitor lizards and snakes.

Prognathodon is best known for its broad, heavy skull and robust jaws. Its conical, thick teeth were built for crushing tough prey like turtles, ammonites, and even other marine reptiles. Depending on the species, Prognathodon could grow up to about 30–40 feet (9–12 meters) long. With a streamlined body and a crescent-shaped tail fin, it was a fast and efficient swimmer, perfectly suited for hunting in open ocean environments.

Prognathodon likely occupied the role of an apex predator in its ecosystem. Its strong bite force suggests it wasn’t picky—it could handle armored prey that other predators avoided. Fossil evidence even hints at scavenging behavior, meaning it may have fed on carcasses as well as live prey.

Fossils of Prognathodon have been discovered across multiple continents, including Europe, North America, Africa, and the Middle East. This wide distribution shows just how successful and adaptable this predator was in ancient seas.

Plesiosaurs were marine reptiles that appeared in the Triassic and died out along with the dinosaurs at the end of the Cretaceous period. They had a broad flat body and a short tail. Their limbs were four powerful flippers that made a flying movement to propel the plesiosaur through the water. Plesiosaurs breathed air, and bore live young. There are indications that plesiosaurs were warm-blooded. There were two main morphological types of plesiosaurs. Those with the "plesiosauromorph" build had a long neck and a small head; these were relatively slow and caught small prey. Others with the "pliosauromorph" build had a short neck and a large head; these were fast hunters and caught large prey.