title: Integrated Chronology, Flora and Faunas, and Paleoecology of the Alajuela Formation, Late Miocene of Panama.
abstract: The late Miocene was an important time to understand the geological, climatic, and biotic evolution of the ancient New World tropics and the context for the Great American Biotic Interchange (GABI). Despite this importance, upper Miocene deposits containing diverse faunas and floras and their associated geological context are rare in Central America. We present an integrated study of the geological and paleontological context and age of a new locality from Lago Alajuela in northern Panama (Caribbean side) containing late Miocene marine and terrestrial fossils (plants, invertebrates, and vertebrates) from the Alajuela Formation. These taxa indicate predominantly estuarine and shallow marine paleoenvironments, along with terrestrial influences based on the occurrence of land mammals. Sr-isotope ratio analyses of in situ scallop shells indicate an age for the Alajuela Formation of 9.77 ± 0.22 Ma, which also equates to a latest Clarendonian (Cl3) North American Land Mammal Age. Along with the roughly contemporaneous late Miocene Gatun and Lago Bayano faunas in Panama, we now have the opportunity to reconstruct the dynamics of the Central America seaway that existed before final closure coincident with formation of the Isthmus of Panama.
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: MacFadden
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Jones
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Jud
authors.affiliation: Smithsonian Tropical Research Institute, Ancon, Panama.
authors.forename: Jorge W
authors.initials: JW
authors.lastname: Moreno-Bernal
authors.affiliation: New Mexico Museum of Natural History, Albuquerque, New Mexico, United States of America.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Morgan
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Roger W
authors.initials: RW
authors.lastname: Portell
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.|Department of Geological Sciences, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Perez
authors.affiliation: Florida Museum of Natural History, University of Florida, Gainesville, Florida, United States of America.|Department of Biology, University of Florida, Gainesville, Florida, United States of America.
authors.forename: Sean M
authors.initials: SM
authors.lastname: Moran
authors.affiliation: Department of Geological & Atmospheric Sciences, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Wood
mesh_terms: D000818:Animals; D044822:Biodiversity; D005580:Fossils; D005844:Geology; D010163:Paleontology; D010176:Panama; D010944:Plants; D013326:Strontium Radioisotopes / Q000032:analysis
chemical_list: D013326:Strontium Radioisotopes