The Cantharus Group of Pisaniine Buccinid Gastropods: Review of the Oligocene to Recent Genera and Description of Some New Species of Gemophos and Hesperisternia

The Cantharus group of pisaniine buccinid gastropods is represented in the Oligocene to Recent interval by twelve genera, two of which are extinct. I review the species composition, synonymy, characteristics, and fossil record of these genera: Anna Risso, 1826 (early Oligocene to Recent, eastern Atlantic); Cancellopollia Vermeij and Bouchet, 1998 (Recent, Indo-West Pacific); Cantharus Rdding, 1798 (Pliocene to Recent, Indo-West Pacific); Editharus Vermeij, 2001a (early Eocene to early Oligocene, Europe); Gemophos Olsson and Harbison, 1953 (late Miocene to Recent, tropical and subtropical America, one species in West Africa); Hesperisternia Gardner, 1944 (late Oligocene to Recent, tropical and subtropical America); Pallia Gray in Sowerby, 1834 (early Miocene to Recent, Indo-West Pacific; one species in West Africa); Preangeria Martin, 1921 (early Miocene to Recent, Indo-West Pacific); Prodotia Dali, 1924 (?late Miocene to Recent, Indo-West Pacific); Pusio Gray in Griffith and Pidgeon, 1834 (?early and middle Miocene, late Miocene to Recent, eastern Pacific); Solenosteira Dali, 1890 (late Miocene to Recent, tropical America); and Zeapollia Finlay, 1927 (Oligocene to Pliocene, Australia and New Zealand). Besides many generic reassignments, I describe the following new species: Gemophos basidentatus (early Pleistocene, Florida); G. crispatus (late Pliocene, Florida); G. filistriatus (Recent, North Carolina to eastern Florida); Hesperisternia binodosa (late Pliocene, Atlantic Costa Rica); H. distans (early Miocene, Venezuela); and H. petuchi (late Miocene, Maryland). New morphological data are presented for Gemophos tridentatus (Tuomey and Holmes, 1857) from the late Pliocene of the southeastern United States. Biogeographically, the Cantharus group conforms to many other shallow-water molluscan clades in having its highest diversity in the Indo-West Pacific (about 25 species), followed by the eastern Pacific (19), western Atlantic (7), and eastern Atlantic (5). Within the western Atlantic, a distinction at the species level between the Gatunian Province (Greater Antilles to Brazil) and the Caloosahatchian Province (southeastern United States) has existed throughout the Neogene. At least three invasions from the Gatunian to the Caloosahatchian Province are documented, two in Gemophos and one in Solenosteira. In addition, Gemophos spread across the Atlantic to West Africa, and extended its range from the Indian Ocean to West Africa. Neogene extinction was most intense in the western Atlantic, where the end of the Pliocene witnessed the regional or global extinction of at least two lineages of Solenosteira and one each of Gemophos and Hesperisternia. Warm-temperate members of the Cantharus group disappeared in the Pliocene and Pleistocene in California, Australia, New Zealand, and the northwestern Atlantic, and survive today only in the Mediterranean.