The Fossil Cypraeidae of the Fruitville Member (Unit 4) and Kissimmee River Valley Equivalent, Tamiami Formation of Southern Florida: (Mollusca: Gastropoda: Cypraeidae)

Abstract

The disappearance of all Pinecrest and equivalent Cypraeidae species from most of their habitats was caused by the circa 200,000 year cooling period in the mid Piacenzian Pliocene, c. 3.2-3.0 mya, and the associated significantly lower sea levels and dry terrestrial conditions in southern Florida. The cooling period was followed by a warming period, which resulted in the Tamiami Subsea being flooded to its maximum size and produced wide-spread tropical conditions throughout southern Florida, roughly similar to today’s southwest Pacific. This resulted in the renewed radiation and speciation of the Cypraeidae populations. In the Myakka Lagoon System, the eight Pinecrest Member (Unit 7) Cypraeidae species in five genera were followed by ten new species in five genera which emerged in Fruitville (Unit 4) time. In the Kissimmee River Valley, the five Unit 7 equivalent species in three genera were followed by eight new species in three genera, which emerged in that area. The number of genera remains consistent at three with the only species previously assigned to Pseudadusta Petuch, 2004 placed into synonymy with Akleistotoma bairdi (Petuch, 2004). This represented a continuation of geographically separate, but parallel, evolutionary tracks.