Beautiful Mosasaurus tooth from Morocco, featuring a well-preserved root and part of the mandibular bone. The bone has been partially restored, but the natural porosity is still clearly visible. It was discovered in the northwestern Sahara region. This Cretaceous marine reptile was one of the largest predators of its time. Mosasaurus was among the last mosasaurs and also one of the largest. Like most mosasaurs, its limbs had evolved into short but efficient flippers, with the front flippers larger than the rear ones. The largest known species, Mosasaurus hoffmannii, could reach lengths of 17–18 meters (56 feet), slightly longer than close relatives such as Tylosaurus and Hainosaurus. Mosasaurus was also one of the most robust mosasaurs, with large individuals estimated to weigh between 25 and 30 tons. Its body was long, thick, and barrel-shaped, with a massive skull and a powerful jaw tightly connected to the cranium. The eyes were relatively large but likely provided limited binocular vision, and the olfactory bulbs were not well developed, suggesting it lived primarily near the water’s surface.