. "Opisthias is a genus of sphenodont reptile. The type species, Opisthias rarus, is known from the Late Jurassic (Kimmeridgian-Tithonian) Morrison Formation of western North America, present in stratigraphic zones 2 and 4\u20136."@en . . . . . . . . "5484"^^ . . "Gilmore, 1905"@en . . . . . . . . . . . "(Possible Berriasian record)"@en . . . "23790193"^^ . . . . "1113124175"^^ . . "Opisthias"@en . . "Gilmore 1909"@en . . . . . . "Opisthias"@en . . . "Opisthias is a genus of sphenodont reptile. The type species, Opisthias rarus, is known from the Late Jurassic (Kimmeridgian-Tithonian) Morrison Formation of western North America, present in stratigraphic zones 2 and 4\u20136."@en . . . . . . . . . . . . "Opisthias rarus"@en . . "Jaw of Opisthias rarus"@en . . . . .