One fossil teeth of Onchosaurus & one of Mosasaur Onchosaurus is an extinct marine reptile that lived during the Late Cretaceous period (about 90-66 million years) Mosasaur is an an extinct marine reptile that lived during the age (about 150-66 million years) The tooth of Onchosaurus length is 6cm and width is 1cm The teeth of Mosasaur length is 10cm Origin Morocco Condition Onchosaurus is Natural And the Mosasaur jaw is composed