<sod>''Mosasaurus'' was among the last of the mosasaurids, and among the largest. As with most mosasaurids, the legs and feet of ''Mosasaurus'' were modified into flippers, and the front flippers were larger than the hind flippers. The largest known species, ''Mosasaurus hoffmannii'', reached lengths up to {{convert|18|m|ft}},<ref name=mulder1999>Mulder, E.W.A. (1999) and M.maximus was {{convert|26|m|ft}}. "Transatlantic latest Cretaceous mosasaurs (Reptilia, Lacertilia) from the Maastrichtian type area and New Jersey." ''Geologie en Mijnbouw'', '''78''': 281–300. {{doi|10.1023/A:1003838929257}}</ref> slightly longer than its relatives ''[[Tylosaurus]]'' and ''[[Hainosaurus]]''. ''Mosasaurus'' was also more robust than related mosasaurids. The skull was more robust than in other mosasaurids, and the lower jaws ([[mandible]]s) attached very tightly to the skull. They had deep, barrel-shaped bodies, and with their fairly large eyes, poor binocular vision, and  poorly developed olfactory bulbs, experts believe that ''Mosasaurus'' lived near the ocean surface, where they preyed on fish, turtles, [[ammonite]]s, smaller mosasaurids, and [[plesiosauria]]ns. Although they were able to dive, they evidently did not venture into deeper waters.<eod>
<sod>''Mosasaurus'' was among the last of the mosasaurids, and among the largest. As with most mosasaurids, the legs and feet of ''Mosasaurus'' were modified into flippers, and the front flippers were larger than the hind flippers. The largest known species, ''Mosasaurus hoffmannii'', reached lengths up to {{convert|18|m|ft}}or M.maximus was {{convert|26|m|ft}},<ref name=mulder1999>Mulder, E.W.A. (1999). "Transatlantic latest Cretaceous mosasaurs (Reptilia, Lacertilia) from the Maastrichtian type area and New Jersey." ''Geologie en Mijnbouw'', '''78''': 281–300. {{doi|10.1023/A:1003838929257}}</ref> slightly longer than its relatives ''[[Tylosaurus]]'' and ''[[Hainosaurus]]''. ''Mosasaurus'' was also more robust than related mosasaurids. The skull was more robust than in other mosasaurids, and the lower jaws ([[mandible]]s) attached very tightly to the skull. They had deep, barrel-shaped bodies, and with their fairly large eyes, poor binocular vision, and  poorly developed olfactory bulbs, experts believe that ''Mosasaurus'' lived near the ocean surface, where they preyed on fish, turtles, [[ammonite]]s, smaller mosasaurids, and [[plesiosauria]]ns. Although they were able to dive, they evidently did not venture into deeper waters.<eod>