Podocnemis unifilis Troschel, 1848 (Reptilia,Testudines): proposed precedence over Emys cayennensis Schweigger, 1812

The purpose of this application, under Article 23.9.3 of the Code, is to conserve the specific name Podocnemis unifilis Troschel, 1848, for a widely distributed species of Amazonian turtle (family PODOCNEMIDIDAE) of both economic and conservation importance, by giving it precedence over its infrequently used senior synonym Podocnemis cayennensis (Schweigger, 1812). This species, the Yellow-spotted River Turtle, has long been referred to as P. unifilis by the IUCN Red List and CITES, as well as in at least 200 scientific publications over more than a century, whereas the name P. cayennensis has only been applied to this species in very few recent publications. Prior to 1974, the name cayennensis had usually been used incorrectly for another species, the Red-headed River Turtle, Podocnemis erythrocephala (Spix, 1824), as noted and corrected by Mittermeier Wilson (1974) and Pritchard Trebbau (1984). The conservation of the binomen P. unifilis will stabilize the use of a name that has been in general use for this species in the vast majority of the scientific publications, government documents, endangered species lists, and the general literature for over 100 years. Giving precedence to the older name (cayennensis) would be counter to usage, and would create much confusion in the literature.