A CATASTROPHIC DEATH ASSEMBLAGE OF A NEW SPECIES OF CORMORANT AND OTHER SEABIRDS FROM THE LATE PLIOCENE OF FLORIDA

A new late Pliocene (upper Pinecrest beds, 2.4-2.0 Ma) fossil locality in Florida has produced thousands of bones and 137 whole and partial skeletons of a new species of cormorant, Phalacrocorax filyawi, that i s related phylogenetically to Recent taxa currently restricted to the eastern north Pacific. Evidence from the bones and the stratigraphy of the site indicate that the cormorants died in a single catastrophic e vent, perhaps a red tide. At least eight other taxa of seabirds and sh orebirds also were recovered from the site and include two new species of gull, Larus perpetuus and L. lacus, described herein. The depositi onal environment reflected by this fauna is a coastal lagoon and beach or shoreline habitat that rarely is preserved in the fossil record of Florida. The fossil cormorant and other seabirds from the Pliocene su pport molluscan evidence that the Florida Gulf Coast was characterized then by cold-water upwelling and a highly productive marine system. M arine cormorants in the eastern Pacific may have extended into the Gul f of Mexico in the early Pliocene during submergence of the Panamanian Isthmus, but became extinct in this region by the end of the Pliocene .