My research centers around Paleogene mammals and problems in paleoclimatology and paleoecology that can be addressed with the use of stable isotopes. In general, I am interested in faunal change and paleoecological change through time, and how those changes may have been influenced by climate. My current research focuses on a series of Paleogene mammalian dispersal events, the largest of which occurred during the Paleocene-Eocene thermal maximum (PETM). The earliest known true primates and modern ungulates (Perissodactyla and Artiodactyla) first appear in North America, Europe, and Asia during the PETM. Their dispersal coincided with extreme short-term warming as evidenced by marine and continental paleoclimate proxies. The arrival of these immigrants dramatically and permanently altered the composition of faunas. Along with collaborators from other institutions, we are developing a high-resolution biostratigraphy and chemostratigraphy through the PETM. Stable isotopes of oxygen and carbon from mammal teeth are providing clues to climate and ecological change that occurred in the PETM.
I am interested in applying similar methods to other intervals of marked climate change to learn more about the response of mammalian communities to climate and ecological change. I am also interested in mammalian biostratigraphy and biochronology for the purpose of placing faunas into a strong geochronologic framework.
- Secord, R., Bloch, J. I., Chester, S. G. B., Boyer, D. M., Wood, A. R., Wing, S. L., Kraus, M. J., McInerney, F. A., and Krigbaum, J., 2012, Evolution of the earliest horses driven by climate change in the Paleocene-Eocene Thermal Maximum, Science, 335, 959-962, doi:10.1126/science.1213859.
- Secord, R. , 2012, Warm spells on land (News and Views), Nature Geoscience, 5, 306-307, doi:10.1038/ngeo1457.
- Kelly, T. S., and Secord, R., 2011, A reevaluation of the mammalian fauna from the Hallelujah Formation, Long Valley, Lassen County, California, Paludicola, 8, 142-154.
- Secord, R., Gingerich, P.D., Lohmann, K.C., and MacLeod, K.G., 2010, Continental warming preceding the Palaeocene-Eocene thermal maximum., Nature, 467, doi:10.1038/nature09441.
- Chester, S.G.B., Block, J.I., Secord, R., and Boyer, D.M., 2010, A new, small species of Palaeonictis (Creodonta, Oxyaenidae> from the Paleocene-Eocene Thermal Maximum, Journal of Mammalian Evolution, 17, 227-243, doi:10.1007/s10914-010-9141-y.
- Kelly, T.S., and Secord, R., 2009, Biostratigraphy of the Hunter Creek Sandstone, Verdi Basin, Washoe County, Nevada, in Oldow, J.S., and Cashman, P.H., eds., Late Cenozoic structure and evolution of the Great Basin-Sierra Nevada transition, Geological Society of America Special Paper, 447, 133-146.
- Secord, R., 2008, The Tiffanian land-mammal age (middle and late Paleocene) in the northern Bighorn Basin, Wyoming, Papers on Paleontology, 35, 1-192.
- Secord, R., Wing, S.L., and Chew, A., 2008, Stable isotopes in early Eocene mammals as indicators of forest canopy structure and resource partitioning, Paleobiology, 282-300.
- Secord, R., Gingerich, P.D., Smith, M.E., Clyde, W.C., Wilf, P., and Singer, B. S., 2006, Geochronology and mammalian biostratigraphy of middle and upper Paleocene continental strata, Bighorn Basin, Wyoming, American Journal of Science, 306, 211-245.