Journal of Paleontology, page 1 of 36 Copyright © 2017, The Paleontological Society 0022-3360/15/0088-0906 doi: 10.1017/jpa.2017.5 Late Miocene chondrichthyans from Lago Bayano, Panama: Functional diversity, environment and biogeography Victor J. Perez,1,2 Catalina Pimiento,3,4 Austin Hendy,4,5 Gerardo González-Barba,6 Gordon Hubbell,7 and Bruce J. MacFadden1,2 1Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA, 〈victorjperez@ufl.edu〉; 〈bmacfadd@flmnh.ufl.edu〉 2Department of Geological Sciences, University of Florida, Gainesville, FL 32611, USA 3Paleontological Institute and Museum, University of Zürich, Ch-8006 Zürich, Switzerland, 〈
[email protected]〉 4Smithsonian Tropical Research Institute, Center for Tropical Paleoecology and Archaeology, Box 2072, Panama, Republic of Panama 5Natural History Museum of Los Angeles, Los Angeles, CA 90007, USA, 〈
[email protected]〉 6Museo de Historia Natural, Area de Ciencias del Mar, La Paz, Universidad Autonoma de Baja California Sur, AP 23080, Mexico, 〈
[email protected]〉 7Jaws International, Gainesville, FL, USA, 〈
[email protected]〉 Abstract.—This newly described chondrichthyan fauna from the late Miocene Chucunaque Formation of Lago Bayano reveals a prolific and highly diverse assemblage from Panama, and one of the richest shark faunas from the Neotropics. Strontium geochronology indicates an age of 10–9.5 Ma for the chonrichthyan-bearing strata. Field efforts resulted in 1429 identifiable specimens comprising at least 31 taxa, of which at least eight are new to the documented fossil record of Panama. With this information an analysis of functional diversity was conducted, indicating ecosystems dominated by generalist species feeding upon a wide range of organisms, from plankton to marine mammals.