First North American fossil monkey and early Miocene tropical biotic interchange.
New World monkeys (platyrrhines) are a diverse part of modern tropical ecosystems in North and South America, yet their early evolutionary history in the tropics is largely unknown. Molecular divergence estimates suggest that primates arrived in tropical Central America, the southern-most extent of the North American landmass, with several dispersals from South America starting with the emergence of the Isthmus of Panama 3-4 million years ago (Ma). The complete absence of primate fossils from Central America has, however, limited our understanding of their history in the New World. Here we present the first description of a fossil monkey recovered from the North American landmass, the oldest known crown platyrrhine, from a precisely dated 20.9-Ma layer in the Las Cascadas Formation in the Panama Canal Basin, Panama. This discovery suggests that family-level diversification of extant New World monkeys occurred in the tropics, with new divergence estimates for Cebidae between 22 and 25 Ma, and provides the oldest fossil evidence for mammalian interchange between South and North America. The timing is consistent with recent tectonic reconstructions of a relatively narrow Central American Seaway in the early Miocene epoch, coincident with over-water dispersals inferred for many other groups of animals and plants. Discovery of an early Miocene primate in Panama provides evidence for a circum-Caribbean tropical distribution of New World monkeys by this time, with ocean barriers not wholly restricting their northward movements, requiring a complex set of ecological factors to explain their absence in well-sampled similarly aged localities at higher latitudes of North America.
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.
Jonathan I
JI
Bloch
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.|Department of Biology, University of Florida, Gainesville, Florida 32611-7800, USA.
Emily D
ED
Woodruff
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.|Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa 50011-1027, USA.
Aaron R
AR
Wood
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.|Department of Geological Sciences, University of Florida, Gainesville, Florida 32611-7800, USA.
Aldo F
AF
Rincon
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.|Department of Biology, University of Florida, Gainesville, Florida 32611-7800, USA.|Department of Evolutionary Anthropology, Duke University, Durham, North Carolina 27708-9976, USA.
Arianna R
AR
Harrington
New Mexico Museum of Natural History and Science, Albuquerque, New Mexico 87104, USA.
Gary S
GS
Morgan
Department of Geological Sciences, University of Florida, Gainesville, Florida 32611-7800, USA.
David A
DA
Foster
Geociencias, Universidad de los Andes, Calle 1A # 18A-10, Edificio IP, Bogotá DC 111711, Colombia.
Camilo
C
Montes
Smithsonian Tropical Research Institute, Box 0843-03092, Balboa, Ancon, Republic of Panama.
Carlos A
CA
Jaramillo
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.
Nathan A
NA
Jud
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.
Douglas S
DS
Jones
Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611-7800, USA.
Bruce J
BJ
MacFadden
D025041:Animal Migration; D000818:Animals; D017691:Caribbean Region; D002427:Cebidae; D065928:Forests; D005580:Fossils; D049690:History, Ancient; D009656:North America; D009792:Oceans and Seas; D010176:Panama; D010802:Phylogeny; D051078:Platyrrhini / Q000033:anatomy & histology / Q000145:classification; D014329:Tropical Climate