Richard F. Frederick Kay
Professor of Evolutionary Anthropology
I have two areas of research:1) the evolution of primates in South America; and 2) the use of primate anatomy to reconstruct the phylogenetic history and adapations of living and extinct primates, especially Anthropoidea.
1) Evolution of primates and mammalian faunal evolution, especially in South America. For the past 30 years, I have been engaged in research in Argentina, Bolivia The Dominican Republic, Peru, and Colombia with three objectives:a) to reconstruct the evolutionary history and adaptive patterns of South America primates and other mammals; b) to establish a more precise geologic chronology for the mammalian faunas between the late Eocene and middle Miocene (between about 36 and about 15 million years ago); and c) to use anatomy and niche structure of modern mammals as a means to reconstruct the evolution of mammalian niche structure in the Neotropics.
2) Primate Anatomy. I am working to reconstruct the phylogeny of primates based (principally) on anatomical evidence; and to infer the adaptations of extinct primates based mainly on cranial and dental evidence.
Current fieldwork is focused on the study of terrestrial biotic change in Patagonia through the 'mid-Miocene Climate Optimum' when global climate was moderate and the subtropical zone, with primates and other typically tropical vertebrates, extended their ranges up to 55 degrees of South latitude.
In this collaborative research undertaking with colleagues at University of Washington and Boise State University, the geochronology of the Santa Cruz Formation at in extreme southern Argentina is being refined using radiometric dating. Stratigraphically-controlled collections have been made of vertebrates and plant macro- and microfossils. Climate change and its impact on the biota is assessed 1) using biogeochemical analysis of stable isotopes in fossil mammalian tooth enamel; 2) by documenting changes in mammalian community structure (richness, origination and extinction rates, and ecological morphology); and 3) by documenting changes in vegetation and floral composition through the study of phytoliths. These three independent lines of evidence in a refined geochronologic framework will then be compared with similar evidence from continental sequences in the Northern Hemisphere and oceanic climatic records to improve our understanding of the timing and character of climatic change in continental high latitudes during this temporal interval.
A second field project project in its early stages is the study of the fossil vertebrates of the Amazon Basin. The latter is a collaborative effort of biologists and geologists across schools at Duke (Nicholas School) and among six North American universities. My role is to direct the vertebrate paleontology component of this project in Brazil and Amazonian Peru. The hope is to recover primates from the Oligocene through Early Miocene. New material will shed light on the phylogenetic status of African Paleogene anthropoids, one of which may be the platyrrhine sister-taxon. Also, new remains of fossil primates will help to refine hypotheses about the origins of the modern families and subfamilies of platyrrhines, all of which trace back to an Early Miocene (17-21 Ma) common ancestor. Finally, new fossil primates may further constrain the time of entry of platyrrhines into South America.
Paleontology And Geochronology Of The Middle Micene Of Sou awarded by National Science Foundation (Principal Investigator). 1992 to 1993
Paleontology And Geochronology Of The Middle Miocene Of So awarded by National Science Foundation (Principal Investigator). 1991 to 1993
Paleontology And Geochronology Of The Middle Miocene Of awarded by National Science Foundation (Principal Investigator). 1990 to 1992
Dental Sexual Di-Morphism In The Catarrhine Primates awarded by National Science Foundation (Principal Investigator). 1989 to 1991
Biochronology And Geochronology Of Friasian (Middle Miocen awarded by National Science Foundation (Principal Investigator). 1989 to 1990
Collaborative Research: Biochronology And Geochronology Of awarded by National Science Foundation (Principal Investigator). 1987 to 1989
Collaborative Research On Sexual Dimorphism In The Definit awarded by National Science Foundation (Principal Investigator). 1986
Collaborative Research On Sexual Dimorphism In The Dentit awarded by National Science Foundation (Principal Investigator). 1984 to 1986
Kay, RF. "Diet." Encyclopedia of Evolution and Prehistory, 2nd Edition. Ed. E Delson, I Tattersall, JA VanCouvering, and A Brooks. New York: Garland Pub. Co., 2000. 208-212.
Meldrum, DJ, and Kay, RF. "The postcranial skeleton of Miocene platyrrhine primates." Vertebrate Paleontology in the Neotropics. Ed. RF Kay, RH Madden, RL Cifelli, and JJ Flynn. Washington, D.C.: Smithsonian Institution Press, 1997. 459-472.
Madden, RH, Guerrero, J, Kay, RF, Flynn, JJ, Swisher III, CC, and Walton, AH. "The Laventan Stage and Laventan Age: New chronostratigraphic and geochronologic units for the Miocene of South America." Vertebrate Paleontology in the Neotropics. Ed. RF Kay, RH Madden, RL Cifelli, and JJ Flynn. Washington, D. C.: Smithsonian Institution Press, 1997. 499-519.
Kay, RF, and Ungar, P. "Dental evidence for diet in some Miocene catarrhines with comments on the effects of phylogeny on the interpretation of adaptation." Function, Phylogeny and Fossils: Miocene Hominoids and Great Ape and Human Origins. Ed. DR Begun, C Ward, and M Rose. New York: Plenum Press, 1997. 131-151.
Kay, RF, and Meldrum, DJ. "A new small platyrrhine from the Miocene of Colombia and the phyletic position of Callitrichinae." Vertebrate Paleontology in the Neotropics. Ed. RF Kay, RH Madden, RL Cifelli, and JJ Flynn. Washington, D.C.: Smithsonian Institution Press, 1997. 435-458.
Kay, RF, and Madden, RH. "Paleogeography and paleoecology." Mammalian Evolution in the Neotropics. Ed. RF Kay, RH Madden, RL Cifelli, and JJ Flynn. Washington, D. C.: Smithsonian Institution Press, 1997. 520-550.
Fleagle, JG, Kay, RF, and Anthony, MRL. "Fossil New World monkeys." Mammalian Evolution in the Neotropics. Ed. RF Kay, RH Madden, RL Cifelli, and JJ Flynn. Washington, D. C.: Smithsonian Institution Press, 1997. 473-495.
Fleagle, JG, and Kay, RF. "Platyrrhines, catarrhines and the fossil record." New World Primates: Ecology, Evolution and Behavior. Ed. WG Kinzey. New York: Aldine, 1997. 3-24.
Kay, RF, and Williams, BA. "Dental evidence for anthropoid origins." Anthropoid Origins: The Fossil Evidence. Ed. JG Fleagle and RF Kay. New York: Plenum Press, 1994. 361-446.
Fleagle, JG, and Kay, RF. "Anthropoid origins: past, present, and future." Anthropoid Origins: The Fossil Evidence. Ed. JG Fleagle and RF Kay. New York: Plenum Press, 1994. 675-698.
Perry, JMG, Kay, RF, Vizcaíno, SF, and Bargo, MS. "Oldest known cranium of a juvenile New World monkey (Early Miocene, Patagonia, Argentina): Implications for the taxonomy and the molar eruption pattern of early platyrrhines." Journal of Human Evolution 74 (January 1, 2014): 67-81. Full Text
Patnaik, R, Milankumar Sharma, K, Mohan, L, Williams, BA, Kay, RF, and Chatrath, P. "Additional Vertebrate Remains from the Early Miocene of Kutch, Gujarat." Special Publication of the Paleontological Society of India 5 (2014): 335-351. Open Access Copy
Fernicola, JC, Cuitiño, JI, Vizcaíno, SF, Bargo, MS, and Kay, RF. "Fossil Localities Of The Santa Cruz Formation (Lower Miocene, Patagonia, Argentina) Prospected By Carlos Ameghino In 1887. The Problem Of The Notohippidian Stage." South American Journal of Earth Sciences 52 (2014): 94-107.
Malinzak, MD, Kay, RF, and Hullar, TE. "Locomotor head movements and semicircular canal morphology in primates." Proc Natl Acad Sci U S A 109.44 (October 30, 2012): 17914-17919. Full Text Open Access Copy
Kay, RF. "Evidence for an Asian origin of stem anthropoids." Proc Natl Acad Sci U S A 109.26 (June 26, 2012): 10132-10133. Full Text Open Access Copy
Allen, KL, and Kay, RF. "Dietary quality and encephalization in platyrrhine primates." Proceedings. Biological Sciences 279.1729 (February 2012): 715-721. Full Text Open Access Copy
Wilson, LAB, Madden, RH, Kay, RF, and Sánchez-Villagra, MR. "Testing a developmental model in the fossil record: Molar proportions in South American ungulates." Paleobiology 38.2 (2012): 308-321. Full Text Open Access Copy
Malinzak, , Kay, MD, Hullar, RF, and E, T. "Predicting locomotion from the primate semicircular canal system." Proceedings of the National Academy (USA) 109 (2012): 17914-17919. (Academic Article)
Kay, R, Allen, K, Gonzales, L, and Krueger, K. "DIETARY RECONSTRUCTION OF ANTILLOTHRIX BERNENSIS, A HOLOCENE MONKEY FROM THE DOMINICAN REPUBLIC." JOURNAL OF VERTEBRATE PALEONTOLOGY 31 (2011): 135-135.
Kay, RF, Hunt, K, Beeker, C, Conrad, G, Johnson, C, and Keller, J. "Preliminary notes on a newly discovered skull of the extinct monkey Antillothrix from Hispaniola and the origin of the Greater Antillean monkeys." Journal of Human Evolution 60.1 (2011): 124-128. Full Text Open Access Copy
Perry, JMG, Kay, RF, Vizcaino, SF, and Bargo, MS. "First Cranial Material of a Juvenile Monkey from the Tertiary of South America: Cranial Anatomy and Dental Eruption Sequence." 2008.
Kay, RF, and Kirk, EC. "New data on encephalization in Miocene New World monkeys: implications for anthropoid brain evolution." 2008.
Krueger, KL, Scott, JR, Ungar, PS, and Kay, RF. "Comparisons of dental microwear texture attributes between facets in three primate taxa." 2008.
Malinzak, M, Kay, RF, Sims, EL, and Queen, R. "Characterization of primate head accelerations during locomotion: A novel application of 3D motion analysis with comparative implications." 2008.
Kay, RF, Simons, E, and Ross, JL. "The basicranial anatomy of African Eocene/Oligocene anthropoids. Are there any clues, for platyrrhine origins?." 2008. Full Text
Vizcaíno, SF, Bargo, MS, and Kay, RF. "Reconstructing the paleoecology of the Santacrucian fauna (Early-Middle Miocene; Patagonia; Argentina) From form and function. Armadillo and primate examples." 2006.
Vizcaíno, SF, Bargo, MS, and Kay, RF. "Morfología y paleobiología de vertebrados. Aplicación a los mamíferos de la Formación Santa Cruz (Mioceno temprano-medio), Patagonia, Argentina." 2006.
Perry, JMG, Kay, RF, and Colbert, MW. "Tooth root size and chewing muscle leverage in Homunculus, a Miocene Primate from Patagonia." 2006.
Kay, RF, and Takai, M. "Pitheciidae and other platyrrhine seed predators: the dual occupation of the seed predator niche during platyrrhine evolution." XXI International Congress of Primatology. Entebe Uganda: International Journal of Primatology, 2006.
Kay, RF, Kirk, EC, Malinzak, M, and Colbert, MW. "Brain size, activity pattern, and visual acuity in Homunculus patagonicus, an early Miocene stem platyrrhine: the mosaic evolution of brain size and visual acuity in Anthropoidea." 2006.