Urotrygon, Gill, 1863

DE CARVALHO, MARCELO R., MAISEY, JOHN G. & GRANDE, LANCE, 2004, Freshwater Stingrays Of The Green River Formation Of Wyoming (Early Eocene), With The Description Of A New Genus And Species And An Analysis Of Its Phylogenetic Relationships (Chondrichthyes: Myliobatiformes), Bulletin of the American Museum of Natural History 2004 (284), pp. 1-136 : 136

Urotrygon , 20, 29, 36, 42, 50, 51, 53, 56, 66, 69,

77, 84, 85, 90, 96, 100, 101–103, 108, 110,

111, 121 U. aspidura , 10 U. chilensis , 10, 33, 34f, 35f, 36, 48, 56, 75f, 82f,

83f, 86f, 87f U. microphthalmum , 10, 77, 93 U. nana , 10 U. venezuelae , 10, 37

† Xiphotrygon , 5, 65, 72

† X. acutidens , 65, 70, 72