56. Kay, R.F., C.F. Ross, and B.A. Williams, Anthropoid Origins. Science, 1997. 275: p. 797-804.[see PDF]
57. Kay, R.F., R.H. Madden, C. Van Schaik, and D. Higdon, Primate species richness is determined by plant productivity: implications for conservation. Proceedings of the National Academy of Sciences (USA), 1997. 94: p. 13023-13027.[see PDF]
58. Kay, R.F., C. Ross, B.A. Williams, and D. Johnson, Cladistic analysis and Anthropoid Origins, reply to Block et al. Science, 1997. 278: p. 2135-2136.[see PDF]
59. Meldrum, D.J. and R.F. Kay, Nuciruptor rubricae, a new pitheciin seed predator from the Miocene of Colombia. American Journal of Physical Anthropology, 1997. 102: p. 407-427.[see PDF]
60. Sánchez-Villagra, M.R. and R.F. Kay, A skull of Proargyrolagus, the oldest argyrolagid (Late Oligocene Salla Beds, Bolivia), with brief comments concerning its paleobiology. Journal of Vertebrate Paleontology, 1997. 17: p. 717-724.
61. Kay, R.F., D.J. Johnson, and D.J. Meldrum, A new pitheciin primate from the middle Miocene of Argentina. American Journal of Primatology, 1998. 45: p. 317-336.[see PDF].
62. Kay, R.F., M. Cartmill, and M. Balow, The hypoglossal canal and the origins of human vocal behavior. Procedings of the National Academy (USA), 1998. 95: p. 5417-5419.[see PDF]
63. Ross, C., B.A. Williams, and R.F. Kay, Phylogenetic analysis of anthropoid relationships. Journal of Human Evolution, 1998. 35: p. 221-306.[see PDF]
64. Kay, R.F., R. Madden, M., M.G. Vucetich, A.A. Carlini, M.M. Mazzoni, G.H. Ré, M. Heizler, and H. Sandeman, Revised age of the Casamayoran South American land Mammals 'Age'-- climatic and biotic implications. Proceedings of the National Academy of Sciences (USA), 1999. 96(23): p. 13235-13240.[see PDF]
65. Kay, R.F., D.J. Johnson, and D.J. Meldrum, Proteropithecia, new name for Propithecia Kay, Johnson and Meldrum, 1998 non Vojnits 1985. American Journal of Primatology, 1999. 47: p. 347.[see PDF]
66. Kay, R.F. and E.C. Kirk, Ostological evidence for the evolution of activity pattern and visual acuity in primates. American Journal of Physical Anthropology, 2000. 113: p. 235-262.[see PDF]
67. Sánchez-Villagra, M., R.F. Kay, and F. Anaya-Daza, Cranial anatomy and paleobiology of the Miocene marsupial Hondalagus altiplanensis and a phylogeny of argyrolagids. Paleontology, 2000. 43: p. 287-301.[see PDF]
67A. Sánchez Villagra, M.R. and R.F. Kay, A skull of Proargyrolagus, the oldest argyrolagid (Late Oligocene Salla Beds, Bolivia), with brief comments concerning its paleobiology. J. Vert. Paleont., 1997. 17: p. 717-724.
68. Sánchez-Villagra, M.R., R.J. Burnham, D.C. Campbell, R.M. Feldmann, E.S. Gaffney, R.F. Kay, R. Lozsán, R. Purdy, and J.G.M. Thewissen, A new near-shore marine fauna and flora from the early Neogene of Northwestern Venezuela. Journal of Paleontology, 2000. 74: p. 957-968.[see PDF]
69. Williams, S. and R.F. Kay, A Comparative Test of Adaptive Explanations for Hypsodonty in Ungulates and Rodents. Journal of Mammalian Evolution, 2001. 8(3): p. 207-229.[see PDF]
70. Bellosi, E.S., S.E. Miquel, R.F. Kay, and R.H. Madden, Un paleosuelo Mustersense con microgastrópodos terrestres (Charopidae) de la Formación Sarmiento, Eoceno de Patagonia central: significado paleoclim‡tico. Ameghiniana, 2002. 39: p. 453-464.[see PDF]
71. Holroyd, P.A., R.L. Ciochon, G.F. Gunnell, R.F. Kay, M. Takai, and M. Godinot, What's in a name? Family-group name taxonomy of larger-bodied Southeast Asian Eocene Primates. Journal of Human Evolution, 2002. 43: p. 755-758.[see PDF]
72. Shigehara, N., M. Takai, R.F. Kay, A.K. Aung, A.N. Soe, T. Tsubamoto, and T. Thein, The upper dentition and face of Pondaungia cotteri from central Myanmar. Journal of Human Evolution, 2002. 42: p. 143-166.[see PDF]
73. Goin, F.J., M.R. Sánchez-Villagra, R.F. Kay, F. Anaya-Diaz, and M. Takai, New paleothentid marsupial from the middle Miocene of Bolivia. Palaeontology, 2003. 46.[see PDF]
74. Jungers, W.L., A.A. Pokempner, R.F. Kay, and M. Cartmill, Hypoglossal canal size in living hominoids and the evolution of human speech. Human Biology, 2003. 75: p. 473-484.[see PDF]
75. Kirk, E.C., M. Cartmill, R.F. Kay, and P. Lemelin, Primate origins and carpolestid relationships: not nailed yet. Comment on Block and Boyer. Science, 2003. 300: p. 471.[see PDF]
76. Kay, R.F., D. Schmitt, C. Vinyard, J.M.G. Perry, M. Takai, N. Shigehara, and N. Egi, The paleobiology of Amphipithecidae, South Asian late Eocene primates. Journal of Human Evolution, 2004. 46: p. 3-25.[see PDF]
77. Kay, R., F. and M.A. Cozzuol, A new platyrrhine from the Solimões Formation (late Miocene, Acre State, Brazil) with comments about other Miocene monkeys from that region. South American Journal of Earth Sciences, 2004.[see PDF preprint ]
78. Kay, R.F., V.M. Campbell, J.B. Rossie, M.W. Colbert, and T. Rowe, The olfactory fossa of Tremacebus harringtoni (Platyrrhini, early Miocene, Sacanana, Argentina): Implications for activity pattern. Anatomical Record, 2004.[see PDF]
79. Kohn, M.J., J.A. Josef, R. Madden, M., R.F. Kay, G. Vucetich, and A. Carlini, Climate stability across the Eocene-Oligocene transition, southern Argentina. Geology, 2004. 32: p. 621-624.[see PDF]
24. Fleagle, J.G., R.F. Kay, and M.R.L. Anthony, Fossil New World monkeys, in Mammalian Evolution in the Neotropics, R.F. Kay, et al., Editors. 1997, Smithsonian Institution Press: Washington, D. C. p. 473-495.
25. Fleagle, J.G. and R.F. Kay, Platyrrhines, catarrhines and the fossil record, in New World Primates: Ecology, Evolution and Behavior, W.G. Kinzey, Editor. 1997, Aldine: New York. p. 3-24.
26. Kay, R.F. and R.H. Madden, Paleogeography and paleoecology, in Mammalian Evolution in the Neotropics, R.F. Kay, et al., Editors. 1997, Smithsonian Institution Press: Washington, D. C. p. 520-550.
27. Kay, R.F. and P. Ungar, Dental evidence for diet in some Miocene catarrhines with comments on the effects of phylogeny on the interpretation of adaptation, in Function, Phylogeny and Fossils: Miocene Hominoids and Great Ape and Human Origins, Begun, D. R., C. Ward, and M. Rose, Editors. 1997, Plenum Press: New York. p. 131-151.
28. Kay, R.F. and D.J. Meldrum, A new small platyrrhine from the Miocene of Colombia and the phyletic position of Callitrichinae, in Vertebrate Paleontology in the Neotropics, R.F. Kay, et al., Editors. 1997, Smithsonian Institution Press: Washington, D.C. p. 435-458[ see PDF].
29. Madden, R.H., J. Guerrero, R.F. Kay, J.J. Flynn, C.C. Swisher III, and A.H. Walton, The Laventan Stage and Laventan Age: New chronostratigraphic and geochronologic units for the Miocene of South America, in Vertebrate Paleontology in the Neotropics., R.F. Kay, et al., Editors. 1997, Smithsonian Institution Press: Washington, D. C. p. 499-519.
30. Meldrum, D.J. and R.F. Kay, The postcranial skeleton of Miocene platyrrhine primates, in Vertebrate Paleontology in the Neotropics, R.F. Kay, et al., Editors. 1997, Smithsonian Institution Press: Washington, D.C. p. 459-472.
31. Kay, R.F., Diet, in Encyclopedia of Evolution and Prehistory, 2nd Edition, E. Delson, et al., Editors. 2000, Garland Pub. Co.: New York. p. 208-212.
32. Kay, R.F., Parapithecidae, in Encyclopedia of Evolution and Prehistory, 2nd Edition, E. Delson, et al., Editors. 2000, Garland Pub. Co.: New York. p. 545-548.
33. Kay, R.F., Teeth, in Encyclopedia of Evolution and Prehistory, 2nd Edition, E. Delson, et al., Editors. 2000, Garland Pub. Co.: New York. p. 695-703.
34. Kay, R.F. and E. Delson, Oligopithecidae, in Encyclopedia of Evolution and Prehistory, 2nd Edition, E. Delson, et al., Editors. 2000, Garland Pub. Co.: New York. p. 490-493 [see PDF].
35. Kay, R.F. and J.A. Van Couvering, Fayum, in Encyclopedia of Evolution and Prehistory, 2nd Edition, E. Delson, et al., Editors. 2000, Garland Pub. Co: New York. p. 265-267.
36. Van Couvering, J.A. and R.F. Kay, Oligocene, in Encyclopedia of Evolution and Prehistory, 2nd Edition, E. Delson, et al., Editors. 2000, Garland Pub. Co: New York. p. 489-490.
37. Kay, R.F., B.A. Williams, and F. Anaya, The adaptations of Branisella boliviana, the earliest South American monkey, in Reconstructing Behavior in the Primate Fossil Record, J.M. Plavcan, et al., Editors. 2001, Kluwer Academic/Plenum Publishers: New York. p. 339-370.[see PDF]
38. Plavcan, J.M., R.F. Kay, W.L. Jungers, and C. van Schaik, Reconstructing behavior in the fossil record, in Reconstructing Behavior in the Primate Fossil Record (Advances in Primatology), J.M. Plavcan, et al., Editors. 2001, Kluwer/Plenum Publishers: New York.
40. Kirk, E.C. and R.F. Kay, The Evolution of High Visual Acuity in the Anthropoidea, in Anthropoid Origins: New Visions, C.F. Ross and R.F. Kay, Editors. 2004, Kluwer/Plenum Publishing: New York. p. 539-602.[see PDF]
41. Ross, C.F. and R. Kay, F., Anthropoid Origins: Retrospective and Prospective, in Anthropoid Origins: New Visions (Advances in primatology), C.F. Ross and R.F. Kay, Editors. 2004, Kluwer/Plenum Publishing: New York. p. 699-737.[see PDF]
42. Ross, C.F. and R.F. Kay, Evolving perspectives on Anthropoidea, in Anthropoid Origins: New Visions, C.F. Ross and R.F. Kay, Editors. 2004, Kulwer/Plenum: New York. p. 3-41.[see PDF]
43. Ungar, P.S., M.F. Teaford, and R.F. Kay, Molar microwear and shearing crest development in Miocene catarrhines. Anthropologie, 2004. 42: p. 21-35.[see PDF]
3. Kay, R.F., R.H. Madden, R.L. Cifelli, and J.J. Flynn, Vertebrate Paleontology in the Neotropics. 1997, Washington, D. C.: Smithsonian Institution Press. 000.
4. Plavcan, J.M., R.F. Kay, W.L. Jungers, and C. van Schaik, Reconstructing Behavior in the Primate Fossil Record. Advances in Primatology. 2001, New York: Kluwer/Plenum Publishers. 437.
5. Ross, C.F. and R.F. Kay, Anthropoid Origins: New Visions (Advances in Primatology). 2004, New York: Kluwer/Plenum Publishers. 749.
Published scientific reviews.
13. Kay, R.F., Review of Adaptive Radiations of Neotropical Primates, edited by M. A. Norconk, A. L. Rosenberger, and P. A. Garber. International Journal of Primatology, 2000, 2:325-32.
14. Kay, R., F., Review of The Primate Fossil Record, edited by W. Hartwig. American Journal of Human Biology, 2003. 15(6): p. 839-840.
44. Kay, R.F. and M.R. Sánchez-Villagra, Skull of Hondalagus, an argyrolagid marsupial from the Middle Miocene of Bolivia. Journal of Vertebrate Paleontology, 1997 [see PDF]
45. Gonzalez, W.G., R.F. Kay, and E.C. Kirk, Optic canal and orbit size-- implications for the origins of diurnality and visual acuity in primates. American Journal of Physical Anthropology, 1998. Suppl 26: p. 87.
46. Heizler, M., R.F. Kay, R.H. Madden, M.M. Mazzzoni, G. Re, H. Sandeman, and M.G. Vucetich, Geochronologic age of the casamayoran fauna at Gran Barranca, Chubut Province, Argentina. Congreso Argentino de Paleontologia y Biostratigrafia, 1998. VII: p. 89.
47. Kay, R.F., M. Cartmill, and M. Balow, The hypoglossal canal and the origins of human vocal behavior. American Journal of Physical Anthropology, 1998. Suppl. 26: p. 137. [see PDF]
48. Madden, R.H., R.F. Kay, M.G. Vucetich, M.M. Mazzoni, G.H. Ré, M. Heizler, and H. Sandeman. Geochronologic age of the Casamayoran fauna at Gran Barranca, Chubut Province, Argentina. 1998.
49. Carlini, A.A., M.G. Vucetich, M. Mazzoni, A. Zucol, G.H. Ré, J.F.A. Vilas, R.F. Kay, R.H. Madden, and M. Heizler, Implications of the late Eocene age of the casamayoran fauna at Gran Barranca, Patagonia. Journal of Vertebrate Paleontology, 1999. 19, Suppl to #3: p. 35A.
50. Kay, R.F., R.H. Madden, M. Mazzoni, M.G. Vucetich, G. Ré, M. Heizler, and H. Sandeman, The oldest Argentine primates: first age determinations for the Colhuehuapian South American Land Mammal 'Age'. American Journal of Physical Anthropology, 1999. Suppl. 28: p. 166. [see PDF]
51. Williams, S.H. and R.F. Kay, A comparative test of competing adaptive explanations for hypsodonty in ungulates and rodents. Programa y Resúmenes, Evolución Neotropical del Cenozoico,La Paz, Bolivia, 1999: p. 46.
52. Zack, S., R.F. Kay, and R.H. Madden, New notoungulates from the Paleogene at Vilcapujio, Bolivia. Journal of Vertebrate Paleontology, 1999. 19, Suppl to #3: p. 86A.
53. Kay, R.F., R.H. Madden, E.S. Bellosi, A.A. Carlini, M. Heizler, G. Ré, F. Vilas, and M.G. Vucetich, Puesto Almendra-Colhue-Huapi contact at Gan Barranca, Sarmiento Formation, Chubut, Argentina. Ameghiniana, 2001. 38(4 (supplement)): p. 35R.
54. Kay, R.F., R.H. Madden, A.A. Carlini, E.S. Bellosi, M. Heizler, G. Ré, F. Vilas, and M.G. Vucetich, The Mustersan interval at Gran Barranca. Ameghiniana, 2001. 38((4) Supplement): p. 34R.
55. Kay, R.F., D. Schmitt, and C. Vinyard, Pondaungia cotteri, a slow moving primate seed predator from the Eocene of South Asia. American Journal of Physical Anthropology, 2002. Supplement 34: p. 92-93. [see PDF]
56. Kirk, E.C., R.F. Kay, and W.L. Jungers, Activity patterns of subfossil lemurs: evidence based on the relative size of the optic canal. Amerian Journal of Primatology, 2002. Supplement 34: p. 96. [see PDF]
57. Kay, R.F. and T.R.T. Mitchell, Cranial evidence for the timing of the catarrhine-platyrrhine divergence. American Journal of Physical Anthropology, 2003. Suppl. 35. [see PDF]
58. Madden, R., M., A. Carlini, G. Vucetich, R. Kay, F., M. Heizler, F. Vilas, G. Re, M.J. Kohn, A. Zucol, and E.S. Bellosi. The terrestrial Eocene-Oligocene transition at Gran Barranca in Patagonia. in Symposium on the Paleogene, Belgium, 25-28 August. 2003. [no PDF]
59. Madden, R., M., A. Carlini, M.G. Vucetich, R. Kay, F., M. Heizler, F. Vilas, G. Re, M.J. Kohn, A. Zucol, and E.S. Bellosi. Gran Barranca: the most complete South American middle Cenozoic sequence. in Symposium on the Paleogene, Belgium, 25-28 August. 2003. [no PDF]
60. Kay, R.F., J.B. Rossie, M.W. Colbert, and T. Rowe, Observations on the olfactory system of Tremacebus harringtoni (Platyrrhini, early Miocene, Sacanana, Argentina) based on high resolution X-ray CT scans. American Journal of Physical Anthropology, 2004. Supplement 35: p. 123-124. [see PDF]
61. Mitchell, T.R.T., R.F. Kay, M.W. Colbert, and T.R. Rowe, The interorbital region of Dolichocebus gaimanensis (Platyrrhini, early Miocene, Argentina) based on high resolution X-ray CT imagingÑphylogenetic implications. American Journal of Physical Anthropology, 2004. Supplement 35: p. 124. [see PDF]
62. Tauber, A.A., R.F. Kay, C. Luna, and M.E. Palacios, Aspectos paleoambientales de la Formación Santa Cruz (Mioceno temprano-medio) en Killik Aike Norte, Patagonia, Argentina. Asociacion Paleontologica Argentina, Reunin Anual de Communicaciones, 2004: p. 26. [see PDF]
63. Vizcaino, S.F., M.S. Bargo, and R.F. Kay, Functional remarks on the humerus of anteaters (Mammalia, Vermilingua) from Santa Cruz Formation (early Middle Miocene). Asociacion Paleontologica Argentina, Reunin Anual de Communicaciones, 2004: p. 29. [see PDF]
64. Vucetich, G., A. Carlini, R. Madden, M., R.F. Kay, and E.C. Vieytes, Nuevos hallazgos entre los más antiguos roedores de América del Sur: una dispersión post transición Eoceno-Oligoceno. Asociacion Paleontologica Argentina, Reunin Anual de Communicaciones, 2004: p. 29. [see PDF]
65. Madden, R., M., R.F. Kay, M. Heizler, F. Vilas, and G. Ré, Geochronology of the Sarmiento Formation at Gran Barranca and elsewhere in Patagonia: calibrating middoe Cenozoic mammal evolution in South America. J. Vert. Paleont., 2004. 24, suppl to #3: p. 87A. [see PDF]
66. Vucetich, G., A. Carlini, R. Madden, M., and R.F. Kay, New discoveries among the oldest rodents in South America: how old and how primitive? J. Vert. Paleont., 2004. 24, suppl to #3: p. 125A. [see PDF]
67. Kay, R.F., S.F. Vizcano, A.A. Tauber, M.S. Bargo, B.A. Williams, C. Luna, and M.W. Colbert, Three newly discovered skulls of Homunculus patagonicus support its position as a stem platyrrhine and establish its diurnal arboreal folivorous habits. Am. J. Phys. Anthropol., in press, 2005. Suppl. [see PDF]
68. Tauber, A.A., R.F. Kay, and C. Luna, Killik Aike Norte, una localidad clásica de la Formación Santa Cruz (Mioceno temprano-medio), Patagonia, Argentina. Ameghiniana, 2004.
69. Tauber, A.A., S.F. Vizcaino, R.F. Kay, M.S. Bargo, and C. Luna, Aspectos biostratigráficos y paleoecológicos de la Formación Santa Cruz (Mioceno temprano-medio) de Patagonia, Argentina. Ameghiniana, 2004.
70. Vizcaino, S.F., M.S. Bargo, A.A. Tauber, and R.F. Kay, The armadillos (Mammalia, Xenarthra) of the Santa Cruz Formation (Early-Middle Miocene). An approach to their paleobiology. Ameghiniana, 2004.