Megistosaurus Anonymous in Harlan, 1828 Dataset GBIF Backbone Taxonomy Rank GENUS Published in Amer. J. Sci., 14, 186. Classification kingdom Animalia phylum Chordata class Mammalia order Cetacea family Physeteridae genus Physeter Name Homonyms Megistosaurus Anonymous, 1828 Megistosaurus Godman, 1827