A Review of the Carolinean Province Americoliva nivosa Complex (Gastropoda: Olividae) with the Description of a New Subspecies
The common eastern North America and Gulf of Mexico olive shell, Americoliva nivosa (Marrat, 1871), is now known to comprise five separate subspecies that are distributed from Cape Hatteras to the Florida Keys, throughout the Gulf of Mexico to Isla Mujeres, and into the open Atlantic as far as Bermuda. The subspecies, which have disjunct distributions, include: Americoliva nivosa clenchi new subspecies (described here) which ranges from Cape Hatteras to Fort Pierce, Florida; Americoliva nivosa bollingi (Clench, 1934), which ranges from Palm Beach County, Florida south to the Florida Keys and Dry Tortugas; Americoliva nivosa choctaw Petuch and Myers, 2014, which ranges from Apalachicola to Pensacola along the Florida Panhandle of the northern Gulf of Mexico; Americoliva nivosa maya (Petuch and Sargent, 1986), which ranges from the Bay of Campeche to Isla Mujeres along the Yucatan Peninsula of Mexico; and Americoliva nivosa nivosa (Marrat, 1871), which is endemic to the island of Bermuda. All five of these distinct subspecies may have evolved from a common ancestor, the mid-Pleistocene (Ionian Age) Americoliva nivosa murielae (Olsson, 1967) from the Bermont Formation of southern Florida. A type locality is also designated for Marrat’s non-localized Americoliva nivosa.