The Genus Trajana (Mollusca: Gastropoda) In the New World

Abstract

The nassarioid gastropod genus Trajana s.s. includes those species with a closed siphonal canal and a circular aperture, surrounded by a raised peristome. There are but four species in the fossil record of the New World, occurring in the upper Miocene of North Carolina, Florida, Mexico, and Peru, and the Pliocene of Ecuador. One of these four is a new species: T. veracruzana E. H. Vokes, from the upper Miocene Agueguexquite Formation of Mexico, and represents the first record of the genus in the "Tertiary Caribbean Province," linking the eastern United States and the western South American occurrences. Another new species, from the middle Miocene Gatun Formation of Panama, is believed to be ancestral to the Trajana s.s. group as it possesses an open siphonal canal and denticulations within the subcircular aperture with a raised peristome like that of Trajana s.s. Because of the fundamental differences this new species is made the type of a new subgenus with the name Trajana (Nerva) woodringi E. H . Vokes. In addition to the fossil species, there are two Recent species of Trajana s.s. found off the coast of western Mexico. All species are treated systematically.