A middle Pleistocene bird community from Saint Lucie County, Florida

Abstract

Dickerson Coquina Pit (DCP) is a sand and coquina mine located in Saint Lucie County, Florida, 16 km inland from the Atlantic Ocean. Collections were made from a middle Pleistocene (late Irvingtonian Land Mammal Age) vertebrate fossil bed in the Okeechobee Formation at DCP from 2002 until the pit was flooded in 2008. Vertebrate fossils from DCP also were discovered in fill material used in beach replenishment on North Hutchinson Island, St. Lucie County. The avifauna of DCP is based on 65 fossil elements representing 12 orders, 16 families, and 26 species, with habitat preferences ranging from woodlands and prairies to fresh water and estuarine wetlands to the open ocean. Extinct or extralocal species include a transitional Wild Turkey Meleagris cf. M. gallopavo, transitional Short-tailed Albatross Phoebastria cf. P. albatrus, a large stork Ciconia maltha, a large crane Grus sp., Great Auk Pinguinus impennis, and Carolina Parakeet Conuropsis carolinensis. The taphonomy and paleoecology of the Dickerson Coquina Pit generally resemble those of other shell beds in Central and South Florida, such as the Irvingtonian Leisey Shell Pit of Hillsborough County. The avifauna from DCP is distinctive, however, in featuring Florida’s first Pleistocene records of four marine species (Short-tailed Albatross, Northern Gannet Morus bassanus, Great Cormorant Phalacrocorax carbo, and Great Auk) and the Carolina Parakeet.