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The decline and extinction of Plesiadapiformes (Mammalia: ?Primates) in North America: displacement or replacement?

  • Mary C. Maas (a1), David W. Krause (a2) and Suzanne G. Strait (a1)


Plesiadapiforms were among the most diverse and abundant of North American mammalian groups during the Paleocene epoch. Their decline and extinction has been attributed to a variety of causes, including competitive exclusion by rodents and/or by primates of modern aspect (euprimates), and the effects of late Paleocene–early Eocene climatic warming. However, analyses of generic and species richness and relative abundance patterns indicate that the decline of plesiadapiforms was more complex than usually supposed. The two major superfamilies, Plesiadapoidea and Microsyopoidea, exhibited very different patterns of decline. Microsyopoids and paromomyid plesiadapoids do not exhibit a pronounced decline in taxonomic richness and relative abundance during the Early Tertiary. Non-paromomyid plesiadapoids do decline markedly, but, when their taxonomic richness and relative abundance patterns are compared with those of potentially competing taxa (rodents and euprimates) only non-paromomyid plesiadapoids and rodents show the inverse relationship consistent with taxonomic displacement. Euprimates appear in North America after non-paromomyid plesiadapoids were virtually extinct. Analyses of body size, diet, diel activity patterns, and locomotion support the hypothesis that rodents and non-paromomyid plesiadapoids may have competed for the same resources; their paleobiogeographic histories also are consistent with the competition argument.

Currently available paleoclimatological data for the Early Tertiary largely pertain to global temperature trends and are not detailed enough to demonstrate unequivocally whether the decline of non-paromomyid plesiadapoids coincided with climatic change. A more complete record of paleoclimatic indicators, especially from the Western Interior of North America, is needed to test the climate hypothesis adequately. The several independent lines of evidence considered here and elsewhere in reference to other mammalian taxa strongly support the hypothesis that competition with rodents was an important factor in a major restructuring of Early Tertiary mammalian communities in North America.



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Archibald, J. D. 1983. Structure of the K–T mammal radiation in North America: speculations on turnover rates and trophic structure. Acta Palaeontologica Polonica 28:717.
Archibald, J. D., Gingerich, P. D., Lindsay, E. H., Clemens, W. A., Krause, D. W., and Rose, K. D. 1987. First North American Land Mammal Ages of the Cenozoic Era. Pp. 2476. In Woodburne, M. W. (ed.), Cenozoic Mammals of North America. University of California Press; Berkeley.
Badgley, C. 1986. Counting individuals in mammalian fossil assemblages from fluvial environments. Palaios 1:328338.
Barth, F. B. 1950. On the relationships of early primates. American Journal of Physical Anthropology 8:139149.
Benton, M. J. 1983a. Dinosaur success in the Triassic: a non-competitive ecological model. Quarterly Review of Biology 58:2955.
Benton, M. J. 1983b. Large-scale replacements in the history of life. Nature 302:1617.
Berggren, W. A., McKenna, M. C., Hardenbol, J., and Obradovich, J. D. 1978. Revised Paleogene polarity time scale. Journal of Geology 86:6781.
Berggren, W. A., Kent, D. V., and Flynn, J. J. 1985a. Jurassic to Paleogene: Part 2. Paleogene geochronology and chronostratigraphy. Pp. 141195. In Snelling, N. J. (ed.), Geochronology and the Geological Record. Geological Society of London, Special Paper No. 10; London.
Berggren, W. A., Kent, D. V., Flynn, J. J., and Van Couvering, J. A. 1985b. Cenozoic geochronology. Geological Society of America Bulletin 96:14071418.
Black, C. C., and Sutton, J. F. 1984. Paleocene and Eocene rodents of North America. Carnegie Museum of Natural History Special Publication 9:6784.
Bown, T. M., and Rose, K. D. 1976. New early Tertiary Primates and a reappraisal of some Plesiadapiformes. Folia Primatologica 26:109138.
Brenchley, P. J. 1984. Introduction. Pp. xi–xv. In Brenchley, P. J. (ed.), Fossils and Climate. John Wiley and Sons; Chichester.
Buchardt, B. 1978. Oxygen isotope palaeotemperatures from the Tertiary period in the North Sea area. Nature 275:121123.
Butler, P. M. 1973. Molar wear facets of Early Tertiary North American Primates. Pp. 127. In Zingeser, M. R. (ed.), Symposia of the Fourth International Congress of Primatology, vol. 3. Craniofacial Biology of Primates. Karger; Basel.
Butler, P. M. 1985. Homologies of molar cusps and crests, and their bearing on assessment of rodent phylogeny. Pp. 381401. In Luckett, W. P., and Hartenberger, J.-L. (eds.), Evolutionary Relationships among Rodents: A Multidisciplinary Analysis. Plenum Press; New York.
Campbell, C. A., and Valentine, J. W. 1977. Comparability of modern and ancient marine faunal provinces. Paleobiology 3:4957.
Carr, T. R., and Kitchell, J. A. 1980. Dynamics of taxonomic diversity. Paleobiology 6:427443.
Cifelli, R. L. 1981. Patterns of evolution among the Artiodactyla and Perissodactyla (Mammalia). Evolution 35:433440.
Connell, J. H. 1980. Diversity and the co-evolution of competitors, or the ghost of competition past. Oikos 35:131138.
Creighton, G. K. 1980. Static allometry of mammalian teeth and the correlation of tooth size and body size in contemporary mammals. Journal of Zoology, London 191:434443.
Emmons, L. H., Gautier-Hion, A., and Dubost, G. 1983. Community structure of the frugivorous-folivorous forest mammals of Gabon. Journal of Zoology, London 199:209222.
Emry, R. J. and Thorington, R. W. Jr. 1982. Descriptive and comparative osteology of the oldest fossil squirrel, Protosciurus (Rodentia: Sciuridae). Smithsonian Contributions to Paleobiology 47.
Fleagle, J. G. 1978. Size distributions of living and fossil primate faunas. Paleobiology 4:6776.
Fleagle, J. G. 1985. Size and adaptation in primates. Pp.119. In Jungers, W. L. (ed.), Size and Scaling in Primate Biology. Plenum Press; New York.
Gingerich, P. D. 1976. Cranial anatomy and evolution of Early Tertiary Plesiadapidae (Mammalia, Primates). University of Michigan Papers on Paleontology 15:1140.
Gingerich, P. D. 1980. Dental and cranial adaptations in Eocene Adapidae. Zeitung für Morphologie und Anthropologie 71:135142.
Gingerich, P. D. 1981. Early Cenozoic Omomyidae and the evolutionary history of tarsiiform primates. Journal of Human Evolution 10:345374.
Gingerich, P. D., Smith, B. H., and Rosenberg, K. 1982. Allometric scaling in the dentition of primates and prediction of body weight from tooth size in fossils. American Journal of Physical Anthropology 58:81100.
Gould, S. J. and Calloway, C. B. 1980. Clams and brachiopods—ships that pass in the night. Paleobiology 6:383396.
Grant, P. R. and Schluter, D. 1984. Interspecific competition inferred from patterns of guild structure. Pp. 202231. In Strong, D. R. Jr., Simberloff, D., Abele, L. G., and Thistle, A. B. (eds.), Ecological Communities: Conceptual Issues and the Evidence. Princeton University Press; Princeton, New Jersey.
Grayson, D. K. 1973. On the methodology of faunal analysis. American Antiquity 38:432439.
Grayson, D. K. 1978. Minimum numbers and sample size in vertebrate faunal analysis. American Antiquity 43:5365.
Gunnell, G. F. 1986. Evolutionary History of Microsyopoidea (Mammalia, Primates?) and the Relationship of Plesiadapiformes to Primates. (Volumes I and II). Unpublished Ph.D. Dissertation, The University of Michigan. Ann Arbor, Michigan. 612 pp.
Gunnell, G. and Gingerich, P. D. 1987. Skull and partial skeleton of Plesiadapis cookei from the Clark's Fork Basin, Wyoming. American Journal of Physical Anthropology 72:206 (abstract).
Hickey, L. 1977. Stratigraphy and paleobotany of the Golden Valley Formation (early Tertiary) of western North Dakota. Geological Society of America, Memoir 150.
Hickey, L. 1980. Paleocene stratigraphy and flora of the Clark's Fork Basin. University of Michigan Papers on Paleontology 24:3349.
Hoffman, A. and Kitchell, J. A. 1984. Evolution in a pelagic planktic system: a paleobiologic test of models of multispecies evolution. Paleobiology 10:933.
Holtzman, R. 1979. Maximum likelihood estimation of fossil assemblage composition. Paleobiology 5:7789.
Hutchinson, G. E. 1959. Homage to Santa Rosalia, or why are there so many kinds of animals? American Naturalist 93:145159.
Jepsen, G. L. 1970. Bat origins and evolution. Pp. 164. In Wimsatt, W. A. (ed.), Biology of Bats. Academic Press; New York and London.
Kay, R. F. 1975. The functional adaptations of primate molar teeth. American Journal of Physical Anthropology 43:195216.
Kay, R. F. 1978. Molar structure and diet in extant Cercopithecidae. Pp. 309339. In Butler, P. M., and Joysey, K. A. (eds.), Development, Function and Evolution of Teeth. Academic Press; New York.
Kay, R. F. and Cartmill, M. 1977. Cranial morphology and adaptations of Palaechthon nacimienti and other Paromomyidae (Plesiadapoidea, ?Primates) with a description of a new genus and species. Journal of Human Evolution 6:1953.
Kay, R. F. and Hiiemae, K. M. 1974. Jaw movement and tooth use in Recent and fossil primates. American Journal of Physical Anthropology 40:227256.
Kay, R. F. and Hylander, W. L. 1978. The dental structure of mammalian folivores with special reference to Primates and Phalangeroidea (Mammalia). Pp. 173191. In Montgomery, G. G. (ed.), The Biology of Arboreal Folivores. Smithsonian Institution Press; Washington, D.C.
Kay, R. F., Sussman, R. W., and Tattersall, I. 1978. Dietary and dental variations in the genus Lemur, with comments concerning dietary-dental correlations among Malagasy primates. American Journal of Physical Anthropology 49:119128.
Kitchell, J. A. 1985. Evolutionary paleoecology: recent contributions to evolutionary theory. Paleobiology 11:91104.
Kitchell, J. A. and Carr, T. R. 1985. Nonequilibrium model of diversification: faunal turnover dynamics. Pp. 277309. In Valentine, J. W. (ed.), Phanerozoic Diversity Patterns. Princeton University Press and Pacific Division, American Association for the Advancement of Science; Princeton, New Jersey and San Francisco, California.
Korth, W. W. 1984. Earliest Tertiary evolution and radiation of rodents in North America. Carnegie Museum of Natural History, Bulletin 24:171.
Krause, D. W. 1986. Competitive exclusion and taxonomic displacement in the fossil record: the case of rodents and multituberculates in North America. Pp. 95117. In Flanagan, K. M., and Lillegraven, J. A. (eds.), Vertebrates, Phylogeny and Philosophy. Contributions to Geology Special Paper 3. The University of Wyoming; Laramie, Wyoming.
Krause, D. W. and Maas, M. C. 1987. Composition and diversity of mammalian faunas across the Torrejonian–Tiffanian boundary in western North America. Geological Society of America abstracts with Programs 19:287.
Krause, D. W. and Maas, M. C. In press. The biogeographic origin of Clarkforkian and Wasatchian mammalian faunas of the Western Interior of North America. In Rose, K. D., and Bown, T. M. (eds.), Dawn of the Age of Mammals. GSA Special Paper.
Krishtalka, L., West, R. M., Black, C. C., Dawson, M. R., Flynn, J. J., Turnbull, W. D., Stucky, R. K., McKenna, M. C., Bown, T. M., Golz, D. J., and Lillegraven, J. A. 1987. Eocene (Wasatchian through Duchesnean) biochronology of North America. Pp. 77117. In Woodburne, M. O. (ed.), Cenozoic Mammals of North America. University of California Press; Berkeley, California.
Lowrie, W. and Alvarez, W. 1981. One hundred million years of geomagnetic polarity history. Geology 9:392397.
Lucas, P. W. 1979. The dental-dietary adaptations of mammals. Neues Jahrbuch für Geologie und Paläontologie, Monatshefte 1979(8):486512.
Lucas, P. W. and Luke, D. A. 1984. Chewing it over: basic principles of food breakdown. Pp. 283301. In Chivers, D. J., Wood, B. A., and Bilsborough, A. (eds.), Food Acquisition and Processing in Primates. Plenum Press; New York.
MacArthur, R. H. 1972. Geographical Ecology. Harper and Row; New York. 269 pp.
Marshall, L. G. 1981. The great American interchange—an invasion-induced crisis for South American mammals. Pp. 133229. In Nitecki, M. H. (ed.), Biotic Crises in Ecological and Evolutionary Time. Academic Press; New York.
Martin, R. D. 1986. Primates: a definition. Pp. 131. In Wood, B., Martin, L., and Andrews, P. (eds.), Major Topics in Primate and Human Evolution. Cambridge University Press; Cambridge.
Matthew, W. D. 1910. On the osteology and relationships of Paramys, and the affinities of the Ischyromyidae. American Museum of Natural History Bulletin 28:4371.
McKenna, M. C. 1960. Fossil Mammalia from the earliest Wasatchian Four Mile fauna, Eocene of northwest Colorado. University of California, Publications in Geological Sciences 37:1130.
Mills, J. R. E. 1955. Ideal dental occlusion in the primates. The Dental Practitioner and Dental Record 6:4763.
Napier, J. R. and Napier, P. H. 1985. The Natural History of the Primates. Massachusetts Institute of Technology Press; Cambridge, Massachusetts. 200 pp.
Newell, N. D. 1952. Periodicity in invertebrate evolution. Journal of Paleontology 26:371385.
Parrish, J. T. 1987. Global palaeogeography and palaeoclimate of the Late Cretaceous and Early Tertiary. Pp. 5172. In Friis, E. M., Chaloner, W. G. and Crane, P. R. (eds.), The Origin of Angiosperms and their Biological Consequences. Cambridge University Press; Cambridge.
Peters, R. H. 1983. The Ecological Implications of Body Size. Cambridge University Press; Cambridge. 329 pp.
Rose, K. D. 1981a. The Clarkforkian Land-Mammal Age and mammalian faunal composition across the Paleocene–Eocene boundary. University of Michigan Papers on Paleontology 26:1197.
Rose, K. D. 1981b. Composition and species diversity in Paleocene and Eocene mammal assemblages: an empirical study. Journal of Vertebrate Paleontology 1:367388.
Rose, K. D. and Bown, T. M. 1982. New plesiadapiform primates from the Eocene of Wyoming and Montana. Journal of Vertebrate Paleontology 2:6369.
Rosenzweig, M. 1968. The strategy of body size in mammalian carnivores. American Midland Naturalist 80:299315.
Roughgarden, J. 1986. A comparison of food-limited and space-limited animal competition communities. Pp. 492516. In Diamond, J., and Case, T. J. (eds.), Community Ecology. Harper and Row; New York.
Roughgarden, J. and Diamond, J. 1986. Overview: the role of species interactions in community ecology. Pp. 333343. In Diamond, J., and Case, T. J. (eds.), Community Ecology. Harper and Row; New York.
Russell, D. E. 1964. Les mammifères paléocènes d'Europe. Mémoires du Muséum D'Histoire Naturelle Série C 13:1324.
Savage, D. E. and Russell, D. E. 1983. Mammalian Paleofaunas of the World. Addison-Wesley; Reading, Massachusetts. 432 pp.
Savin, S. M. 1977. The history of the earth's surface temperature during the past 100 million years. Annual Review of Earth and Planetary Sciences 5:319355.
Sepkoski, J. J. Jr. 1978. A kinetic model of Phanerozoic taxonomic diversity. I. Analysis of marine orders. Paleobiology 4:223251.
Sepkoski, J. J. Jr. 1984. A kinetic model of Phanerozoic taxonomic diversity. III. Post-Paleozoic families and mass extinctions. Paleobiology 10:246267.
Sepkoski, J. J. Jr., Bambach, R. K., Raup, D. M., and Valentine, J. W. 1981. Phanerozoic marine diversity and the fossil record. Nature 293:434437.
Shackleton, N. J. 1984. Oxygen isotope evidence for Cenozoic climatic change. Pp. 2734. In Brenchley, P. (ed.), Fossils and Climate. John Wiley and Sons; Chichester.
Shackleton, N. J. and Kennett, J. P. 1975. Paleotemperature history of the Cenozoic and the initiation of Antarctic glaciation: oxygen and carbon isotope analyses in DSDP Sites 277, 279 and 281. In Kennett, J. P., Houtz, R. E. et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Vol. 29. U.S. Government Printing Office; Washington D.C.
Simberloff, D. 1983. Competition theory, hypothesis testing, and other community ecological buzzwords. American Naturalist 122:626635.
Simons, E. L. 1964. The early relatives of man. Scientific American 211:250262.
Simons, E. L. 1967. Fossil primates and the evolution of some primate locomotor systems. American Journal of Physical Anthropology 26:241254.
Simons, E. L. 1974. Notes on Early Tertiary prosimians. Pp. 415433. In Martin, R. D., Doyle, G. A., and Walker, A. C. (eds.), Prosimian Biology. Duckworth; London.
Simpson, G. G. 1953. The Major Features of Evolution. Columbia University Press; New York. 434 pp.
Sloan, R. E. 1987. Paleocene and latest Cretaceous mammal ages, biozones, magnetozones, rates of sedimentation, and evolution. Geological Society of America Special Paper 209:165200.
Sokal, R. R. and Rohlf, F. J. 1981. Biometry. W. H. Freeman and Company; San Francisco, California. 859 pp.
Stanley, S. M. 1979. Macroevolution: Pattern and Process. W. H. Freeman and Company; San Francisco, California. 332 pp.
Stenseth, N. C. and Maynard-Smith, J. 1984. Coevolution in ecosystems: Red Queen evolution or stasis? Evolution 38:870880.
Storer, J. E. 1984. Mammals of the Swift Current Creek local fauna (Eocene: Uintan), Saskatchewan. Saskatchewan Culture and Recreation, Museum of Natural History, Natural History Contributions No. 7. 158 pp.
Strong, D. R. Jr., Szyska, L. A., and Simberloff, D. 1979. Tests of community-wide character displacement against null hypotheses. Evolution 33:897913.
Strong, D. R., Simberloff, D., Abele, L. G., and Thistle, A. B. (eds.). 1984. Ecological Communities: conceptual issues and the evidence. Princeton University Press; Princeton, New Jersey. 613 pp.
Sussman, R. W. and Raven, P. H. 1978. Pollination by lemurs and marsupials: an archaic coevolutionary system. Science 200:731736.
Szalay, F. S. 1972. Paleobiology of the earliest primates. Pp. 335. In Tuttle, R. (ed.), The Functional and Evolutionary Biology of Primates. Aldine-Atherton; Chicago.
Szalay, F. S. 1977. Phylogenetic relationship and a classification of the eutherian Mammalia. Pp. 315374. In Hecht, M. K., Goody, P. C., and Hecht, B. M. (eds.), Major Patterns in Vertebrate Evolution. NATO Advanced Study Institute, Series A, vol. 14. Plenum Publishing Company; New York.
Szalay, F. S. 1981. Phylogeny and the problem of adaptive significance: the case of the earliest primates. Folia Primatologica 36:157182.
Szalay, F. S. 1985. Rodent and lagomorph morphotype adaptations, origins and relationships: some postcranial attributes analyzed. Pp. 83132. In Luckett, W. P., and Hartenberger, J. -L. (eds.), Evolutionary Relationships among Rodents: a Multidisciplinary Analysis. Plenum Press; New York.
Szalay, F. S. and Dagosto, M. 1980. Locomotor adaptations as reflected on the humerus of Paleogene primates. Folia Primatologica 34:145.
Szalay, F. S. and Decker, R. L. 1974. Origins, evolution and function of the tarsus in late Cretaceous eutherians and Paleocene primates. Pp. 223259. In Jenkins, F. A. Jr. (ed.), Primate Locomotion. Academic Press; New York.
Szalay, F. S. and Delson, E. 1979. Evolutionary History of the Primates. Academic Press; New York. 580 pp.
Szalay, F. S. and Drawhorn, G. 1980. Evolution and diversification of the Archonta in an arboreal milieu. Pp. 133169. In Luckett, W. P. (ed.), Comparative Biology and Evolutionary Relationships of Tree Shrews. Plenum Press; New York.
Szalay, F. S. and Li, C.-K. 1986. Middle Paleocene euprimate from southern China and the distribution of primates in the Paleogene. Journal of Human Evolution 15:387397.
Szalay, F. S., Tattersall, I., and Decker, R. L. 1975. Phylogenetic relationships of Plesiadapis—postcranial evidence. Pp. 136166. In Szalay, F. S. (ed.), Contributions to Primatology Vol. 5: Approaches to Primate Paleobiology. Karger; Basel.
Tidwell, W. D., Ash, S. R., and Parker, I. R. 1981. Cretaceous and Tertiary floras of the San Juan Basin. Pp. 307332. In Lucas, S. G., Rigby, J. K. Jr., and Kues, B. S. (eds.), Advances in San Juan Basin Paleontology. University of New Mexico Press; Albuquerque.
Van Valen, L. 1971. Adaptive zones and the orders of mammals. Evolution 25:420428.
Van Valen, L. and Sloan, R. E. 1966. The extinction of the multituberculates. Systematic Zoology 15:261278.
Webb, S. D. 1985. Late Cenozoic mammal dispersals between the Americas. Pp. 357386. In Stehli, F. G., and Webb, S. D. (eds.), The Great American Biotic Interchange. Plenum Press; New York.
West, R. M. 1973. Geology and mammalian paleontology of the New Fork-Big Sandy area, Sublette County, Wyoming. Field Museum of Natural History, Fieldiana: Geology 29:1193.
Wilson, D. S. 1975. The adequacy of body size as a niche difference. American Naturalist 109:769784.
Wing, S. L. 1980. The Willwood Formation (Lower Eocene) of the Southern Bighorn Basin, Wyoming, and its mammalian fauna. University of Michigan Papers on Paleontology 24:119126.
Wing, S. L. 1981. A Study of Paleoecology and Paleobotany in the Willwood Formation (Early Eocene, Wyoming). Unpublished Ph.D. Dissertation, Yale University. New Haven, Connecticut. 391 pp.
Wing, S. L. 1987. Eocene and Oligocene floras and vegetations of the Rocky Mountains. Annals of the Missouri Botanical Gardens 74:748784.
Wing, S. L. and Bown, T. M. 1985. Fine scale reconstruction of late Paleocene–early Eocene paleogeography in the Bighorn Basin of Northern Wyoming. Pp. 93105. In Flores, R. M., and Kaplan, S. S. (eds.), Cenozoic Paleogeography of the West-Central United States. Rocky Mountain Paleogeography Symposium 3. The Rocky Mountain Section Society of Economic Paleontologists and Mineralogists; Denver, Colorado.
Wolberg, D. L. 1978. The Mammalian Paleontology of the Late Paleocene (Tiffanian) Circle and Olive Localities, McCone and Powder River Counties, Montana. Unpublished Ph.D. Dissertation, University of Minnesota. Minneapolis, Minnesota. 385 pp.
Wolfe, J. A. 1978. A paleobotanical interpretation of Tertiary climates in the Northern Hemisphere. American Scientist 66:694703.
Wolfe, J. A. 1985. Distribution of major vegetational types during the Tertiary. Pp. 357375. In Sundquist, E. T., and Broecker, W. S. (eds.), The Carbon Cycle and Atmospheric CO2: Natural Variations Archean to Present. Geophysical Monograph 32. American Geophysical Union; Washington, D.C.
Wolfe, J. A. 1987a. Late Cretaceous–Cenozoic history of deciduousness and the terminal Cretaceous event. Paleobiology 13:215226.
Wolfe, J. A. 1987b. An overview of the origins of the modern vegetation and flora of the northern Rocky Mountains. Annals of the Missouri Botanical Garden 74:785803.
Wolfe, J. A. and Hopkins, D. M. 1967. Climatic changes recorded by Tertiary land floras in northwestern North America. Pp. 6776. In Hatai, K. (ed.), Tertiary Correlation and Climatic Changes in the Pacific. 11th Pacific Scientific Congress, Symposium Vol. 25.
Wolfe, J. A. and Poore, R. Z. 1982. Tertiary marine and non-marine climatic trends. Pp. 154158. In Geophysics Study Committee, Geophysics Research Board, Commission on Physical Sciences, Mathematics and Resources, National Research Council (compilers), Climate in Earth History. National Academy Press; Washington, D.C.
Wolfe, J. A. and Upchurch, G. R. Jr. 1986. Vegetation, climatic and floral changes at the Cretaceous–Tertiary boundary. Nature 324:148152.
Wood, A. E. 1962. The Early Tertiary rodents of the family Paramyidae. Transactions of the American Philosophical Society 52:1261.


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