An early Irvingtonian avifauna from Leisey Shell Pits, Hillsborough County, Florida

Abstract

A new early Irvingtonian avifauna is reported from Leisey Shell Pit, Hillsborough County, Florida. Bones of at least 30 extant and 15 extinct taxa are identified, including new species of spoonbill (Ajaia chione) and ibis (Eudocimus leiseyi). The avifauna is composed primarily of aquatic and wading species, with the earliest fossil occurrence of trumpeter swan (Cygnus buccinator), spoonbill, extinct flamingo (Phoenicopterus copei), eagle (Amplibuteo sp.) and the teratorn (Teratornis merriami), and the latest occurrence of an extinct loon (Gavia concinna). The flamingo, eagle, a large teratorn (Teratornis cf. T. incredibilis), and an extinct goose (Branta dickeyi) are also the first records of these taxa in the eastern U. S. The avifauna is indicative of a paleoenvironment of a coastal tidal marsh or wetland with nearby mud flats and sandy shores. This habitat is common along the Gulf Coast of Florida today, but lacks the diversity of avian species that was present in the early Pleistocene.