The Genus Conus (Mollusca:Neogastropoda) in the Plio-Pleistocene of the Southeastern United States


Book Description

Conus (or cone) shells are common in many Pliocene and Pleistocene fossil deposits from the Coastal Plain of the southeastern United States, but have never been the subjects of a comprehensive taxonomic review or revision. In total, 84 names (including those of some Recent species and fossil taxa from other strata or areas) have been applied to Plio-Pleistocene cone shells from this region, and since Green described Conus marylandicus in 1830, and additional 59 species have been described from these strata. Forty of these taxa were described in the last 17 years and were published outside of the peer-reviewed literature, making their status as distinct species suspect, particularly because most are poorly illustrated, perfunctorily described, and based on few specimens. This makes them nearly impossible to evaluate without direct inspection of type material and/or access to large suites of specimens. Evaluating whether these suspect taxon names represent distinctive morphospecies is critical to attaining an understanding of the evolutionary history and diversity of Neogene and Recent Conus in the western Atlantic. The present work provides a systematic treatment of 82 of the 84 names that have been applied to Conus shells from the Plio-Pleistocene fossil records of Virginia, North Carolina, South Carolina, and Florida. Here, through application of a conservative morphological species concept (one that accepts large amounts of intraspecific morphological variation), 19 of these nominal taxa are accepted as representing distinctive species of Plio-Pleistocene Conus from this study area. In addition, this investigation also resulted in the discovery of one new fossil morphospecies, described here as Conus burnetti n. sp. An identification key to these 20 species is provided. The status of three additional, previously described species (known only by their type specimens) remains less certain. Two names that are likely familiar to collectors of Plio-Pleistocene Conus from the United States Coastal Plain, C. floridanus Gabb, 1869, and C. druidi Olsson, 1967, are synonymized, respectively, with G. fg. largillierti Kiener, 1845, and C. haytensis G. B. Sowerby II, 1850. All previously described species of sinistral Conus are considered to belong to one highly morphologically variable species, C. adversarius Conrad, 1840.