Genus HYDROTHEROSAURUS
Kingdom / Phylum . . . . . . . . Subphylum / Superclass . . . . Class / Subclass / Infraclass Division / Superorder / Order Suborder / Infraorder . . . . . . Superfamily / Family . . . . . . . Subfamily / Genus . . . . . . . . .	Animalia / Chordata Cephalochordata / Gnathostomata Reptilia / Diapsida / Lepidosauromorpha n.a. / Sauropterygia / Plesiosauria n.a. / n.a. Plesiosauroidea / Elasmosauridae n.a. / Hydrotherosaurus
Age: Distribution:	Late Cretaceous North America
Depicted on: Chad, 2021 (position 2 of sheet) Saint Kitts, 1994 (1,20 $., also with overprinted logo) Sierra Leone, 2020 (position 2 of sheet)