Richard Frederick Kay
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. "Teeth." Encyclopedia of Evolution and Prehistory, 2nd Edition. Ed. E Delson, I Tattersall, JAV Couvering, and A Brooks. New York: Garland Pub. Co., 2000. 695-703.
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.
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 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.
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
Allen, K, Gonzales, L, Cooke, S, and Kay, R. "EVALUATION OF UPPER MOLAR OCCLUSAL MORPHOLOGY FOR DIETARY INFERENCE IN MID- TO LARGE-BODIED PLATYRRHINI (PRIMATES)." JOURNAL OF VERTEBRATE PALEONTOLOGY 31 (2011): 61-61.
Williams, BA, Kay, RF, Kirk, EC, and Ross, CF. "Darwinius masillae is a strepsirrhine-a reply to Franzen et al. (2009)." Journal of Human Evolution 59.5 (2010): 567-573. Full Text
Coleman, MN, Kay, RF, and Colbert, MW. "Auditory morphology and hearing sensitivity in fossil new world monkeys." Anatomical Record 293.10 (2010): 1711-1721. Full Text
Kay, RF, and Fleagle, JG. "Stem taxa, homoplasy, long lineages, and the phylogenetic position of Dolichocebus." Journal of Human Evolution 59.2 (2010): 218-222. Full Text
Perry, JMG, Kay, RF, Vizcaíno, SF, and Bargo, MS. "Tooth root size, chewing muscle leverage, and the biology of Homunculus patagonicus (Primates) from the late early Miocene of Patagonia." Ameghiniana 47.3 (2010): 355-371.
Vizcaíno, SF, Bargo, MS, Kay, RF, Fariña, RA, Giacomo, MD, Perry, JMG, Prevosti, FJ, Toledo, N, Cassini, GH, and Fernicola, JC. "A baseline paleoecological study for the Santa Cruz Formation (late-early Miocene) at the Atlantic Coast of Patagonia, Argentina." Palaeogeography, Palaeoclimatology, Palaeoecology 292.3-4 (2010): 507-519. Full Text
Bargo, MS, Vizcaíno, SF, and Kay, RF. "Predominance of orthal masticatory movements in the early Miocene Eucholaeops (Mammalia, Xenarthra, Tardigrada, Megalonychidae) and other megatherioid sloths." Journal of Vertebrate Paleontology 29.3 (2009): 870-880. Full Text
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
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.
Kay, RF, Rae, TC, Koppe, T, and Colbert, MW. "Paranasal pneumatization in the early Miocene platyrrhine Homunculus patagonicus." 2006.
Mitchell, TRT, Schmitt, D, and Kay, RF. "The role of binocular vision in primate locomotion." 2006. Open Access Copy
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.