Genus OPISTHIAS
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. / Lepidosauria / Sphenodontida n.a. / n.a. n.a. / Sphenodontidae n.a. / Opisthias
Age: Distribution:	Late Jurassic North America
Depicted on: United States, 1997 (position 8 of sheet)