The Genus Turbinella (Mollusca, Gastropoda) in the New World

Abstract

Two lines of T urbinella have developed from the ancestral Eocene species, one in the Old World and one in the New World. The evolutionary development of these has been remarkably parallel, although apparently separate. In both regions the earliest species are shouldered forms, and successive species become increasingly smooth. In the New World a secondary group developed in the lower Miocene. This branch, here called the 11angulata11 lineage, is marked by an exceedingly large nucleus, and by a noded shoulder in contrast to the smooth outline of the primary form, here termed the 11laevigatan lineage. In this paper the 24 known species of New World Turbinellinae are treated systematically, and one new species, Turbinella dalli1 is described. In addition the homonym T. praeovoidea Maury, non Vredenburg, is replaced by T. praelaevigata1 nom. nov.