title: Formation of the Isthmus of Panama.
abstract: The formation of the Isthmus of Panama stands as one of the greatest natural events of the Cenozoic, driving profound biotic transformations on land and in the oceans. Some recent studies suggest that the Isthmus formed many millions of years earlier than the widely recognized age of approximately 3 million years ago (Ma), a result that if true would revolutionize our understanding of environmental, ecological, and evolutionary change across the Americas. To bring clarity to the question of when the Isthmus of Panama formed, we provide an exhaustive review and reanalysis of geological, paleontological, and molecular records. These independent lines of evidence converge upon a cohesive narrative of gradually emerging land and constricting seaways, with formation of the Isthmus of Panama sensu stricto around 2.8 Ma. The evidence used to support an older isthmus is inconclusive, and we caution against the uncritical acceptance of an isthmus before the Pliocene.
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.
authors.forename: Aaron
authors.initials: A
authors.lastname: O'Dea
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.
authors.forename: Harilaos A
authors.identifier: 0000-0003-4726-1382
authors.initials: HA
authors.lastname: Lessios
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.
authors.forename: Anthony G
authors.initials: AG
authors.lastname: Coates
authors.affiliation: Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA.
authors.forename: Ron I
authors.initials: RI
authors.lastname: Eytan
authors.affiliation: Departamento de Geociencias y Medio Ambiente Universidad Nacional de Colombia, Bogotá, Colombia.; Department of Geological Sciences, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Restrepo-Moreno
authors.affiliation: División Paleontología Vertebrados, Museo de La Plata, B1900FWA La Plata, Buenos Aires, Argentina.
authors.forename: Alberto L
authors.initials: AL
authors.lastname: Cione
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.; Department of Earth and Environment, and Department of Biological Sciences, Florida International University, Miami, FL 33199, USA.
authors.forename: Laurel S
authors.identifier: 0000-0003-4181-7271
authors.initials: LS
authors.lastname: Collins
authors.affiliation: Department of Biology, University of Nevada, Reno, NV 89557-0314, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: de Queiroz
authors.affiliation: Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL 32306, USA.
authors.forename: David W
authors.identifier: 0000-0002-8728-2746
authors.initials: DW
authors.lastname: Farris
authors.affiliation: Scripps Institution of Oceanography, La Jolla, CA 92093-0244, USA.
authors.forename: Richard D
authors.identifier: 0000-0001-5288-1733
authors.initials: RD
authors.lastname: Norris
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.; U.S. Geological Survey, 3215 Marine Street (Suite E127), Boulder, CO 80303, USA.
authors.forename: Robert F
authors.identifier: 0000-0001-8209-7608
authors.initials: RF
authors.lastname: Stallard
authors.affiliation: Department of Geological Sciences, University of California, Riverside, Riverside, CA 92507, USA.
authors.forename: Michael O
authors.identifier: 0000-0003-2516-9622
authors.initials: MO
authors.lastname: Woodburne
authors.affiliation: Universidade Federal Fluminense, Instituto de Biologia, Campus do Valonguinho, Outeiro São João Batista, s/n°, cep. 24020-141, Niterói, Rio de Janeiro, Brazil.
authors.forename: Orangel
authors.initials: O
authors.lastname: Aguilera
authors.affiliation: Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854-8066, USA.
authors.forename: Marie-Pierre
authors.identifier: 0000-0002-5613-5559
authors.initials: MP
authors.lastname: Aubry
authors.affiliation: Department of Earth and Planetary Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854-8066, USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Berggren
authors.affiliation: Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242, USA.
authors.forename: Ann F
authors.initials: AF
authors.lastname: Budd
authors.affiliation: Laboratório de Paleozoologia, Departamento de Biologia Geral, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, cep. 31270 010, Belo Horizonte, MG, Brazil.
authors.forename: Mario A
authors.identifier: 0000-0003-3645-0401
authors.initials: MA
authors.lastname: Cozzuol
authors.affiliation: Department of Biology, Hamilton College, 198 College Hill Road, Clinton, NY 13323, USA.
authors.forename: Simon E
authors.initials: SE
authors.lastname: Coppard
authors.affiliation: Academia Colombiana de Ciencias Exactas, Físicas y Naturales, Bogotá, Colombia.
authors.forename: Herman
authors.initials: H
authors.lastname: Duque-Caro
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Science Building #3140, Berkeley, CA 94720-3140, USA.
authors.forename: Seth
authors.identifier: 0000-0002-6175-6173
authors.initials: S
authors.lastname: Finnegan
authors.affiliation: División Paleontología Vertebrados, Museo de La Plata, B1900FWA La Plata, Buenos Aires, Argentina.
authors.forename: Germán M
authors.initials: GM
authors.lastname: Gasparini
authors.affiliation: Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Ethan L
authors.identifier: 0000-0002-1045-6939
authors.initials: EL
authors.lastname: Grossman
authors.affiliation: Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK.
authors.forename: Kenneth G
authors.initials: KG
authors.lastname: Johnson
authors.affiliation: Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA.
authors.forename: Lloyd D
authors.initials: LD
authors.lastname: Keigwin
authors.affiliation: Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Knowlton
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.
authors.forename: Egbert G
authors.initials: EG
authors.lastname: Leigh
authors.affiliation: Department of Geology, Washington and Lee University, 204 West Washington Street, Lexington, VA 24450, USA.
authors.forename: Jill S
authors.initials: JS
authors.lastname: Leonard-Pingel
authors.affiliation: Department of Biology, University of Hawai'i at Mānoa, 2538 McCarthy Mall, Honolulu, HI 96822, USA.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Marko
authors.affiliation: Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.
authors.forename: Nicholas D
authors.identifier: 0000-0003-4678-5782
authors.initials: ND
authors.lastname: Pyenson
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.; Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA.
authors.forename: Paola G
authors.identifier: 0000-0002-2056-9101
authors.initials: PG
authors.lastname: Rachello-Dolmen
authors.affiliation: División Paleontología Vertebrados, Museo de La Plata, B1900FWA La Plata, Buenos Aires, Argentina.
authors.forename: Esteban
authors.initials: E
authors.lastname: Soibelzon
authors.affiliation: División Paleontología Vertebrados, Museo de La Plata, B1900FWA La Plata, Buenos Aires, Argentina.
authors.forename: Leopoldo
authors.identifier: 0000-0002-9373-3494
authors.initials: L
authors.lastname: Soibelzon
authors.affiliation: Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK.
authors.forename: Jonathan A
authors.identifier: 0000-0002-0433-1611
authors.initials: JA
authors.lastname: Todd
authors.affiliation: Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA.
authors.forename: Geerat J
authors.initials: GJ
authors.lastname: Vermeij
authors.affiliation: Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Republic of Panama.; Scripps Institution of Oceanography, La Jolla, CA 92093-0244, USA.; Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.
authors.forename: Jeremy B C
authors.initials: JB
authors.lastname: Jackson
mesh_terms: D000569:Americas; D005075:Biological Evolution; D017753:Ecosystem; D004777:Environment; D005580:Fossils; D005844:Geology; D009792:Oceans and Seas; D010163:Paleontology; D010176:Panama; D058974:Phylogeography
keywords: Central America; Evolution; GABI; Isthmian closure; ecology; land-bridge