Thomas E. Williamson

    Vertebrate Paleontologist

Publications - Paleocene



Recent presentations of our research:

Heizler, M. T., I. P. Mason, and T. E. Williamson, 2013. My Dates – Community Rates. William Smith Meeting of the Geological Society of London, Abstract with Programs. (abstract)

 Heizler, M. T., I. P. Mason, T. E. Williamson, D. J. Peppe, J. Ramezani, and S. A. Bowring. 2013. 40Ar/39Ar Chronostratigraphy of Cretaceous and Paleocene strata in the San Juan Basin, New Mexico: Accuracy limitations of high precision measurements. Geological Society of America, Abstract with Programs 114-9.

Hobbs, K. M., T. E. Williamson, and P. J. Fawcett. 2012. Early Paleocene temperature and precipitation estimates from paleosols at Kimbeto Wash, San Juan Basin, New Mexico, U.S.A. Geological Society of America, Program with Abstracts 44(6):69. (abstract)

Mason, I. P., M. T. Heizler, and T. E. Williamson, 2013. 40AR/39AR sanidine chronostratigraphy of K-Pg boundary sediments of the San Juan Basin, NM. Geological Society of America, Rocky Mountain Section, Abstract with Programs 15-4. (abstract)

Peppe, D. J., M. T. Heizler, T. E. Williamson, I. P. Mason, S. L. Brusatte, A. Weil, and R. Secord. 2013. New age constraints on Upper Cretaceous through lower Paleocene age rocks in the San Juan Basin, New Mexico. Geological Society of America, Abstracts with Programs 114-10. (abstract)

Secord, R., T. E. Williamson, and A. Weil. 2012. Stable isotope ecology of early Paleocene (Puercan and Torrejonian) mammals from the San Juan Basin, New Mexico. Journal of Vertebrate Paleontology, Program and Abstracts, 2012:170. (abstract)

Templeman, T. and T. E. Williamson. 2013. The Armijo Draw local fauna from the Santonian – lower Campanian Menefee Formation, San Juan Basin, New Mexico. Journal of Vertebrate Paleontology, Program and Abstracts, 2013:224. (abstract) 

Weil, A. B., B. McCullough, and T. E. Williamson. 2012. Newly reported multituberculate mammals from the Paleocene of the San Juan Basin of New Mexico. Geological Society of America, Programs with Abstracts 44(6):90.

Williamson, T. E. and S. L. Brusatte. 2013. New specimens of Wortmania (Mammalia: Taeniodonta) from the early Paleocene (Puercan) of New Mexico. Journal of Vertebrate Paleontology, Program and Abstracts, 2013:238. (abstract)

Williamson, T. E., S. L. Brusatte, D. J. Peppe, R. Secord, and A. Weil. 2012. No evidence for conformable contact between the Ojo Alamo Sandstone and the Nacimiento Formation. New Mexico Geology 34 (abstract)Williamson, T. E. and T. Templeman, 2013. A new vertebrate local fauna from the Menefee Formation, San Juan Basin, New Mexico. New Mexico Geology. (abstract) 

Williamson, T. E. and A. Weil. 2013. Small theropod teeth from the Upper Cretaceous Fruitland and Kirtland formations (late Campanian Hunter Wash and late Maastrichtian Alamo Wash local faunas), San Juan Basin, northwestern New Mexico. Burpee Museum of Natural History PaleoFest Program with Abstracts. (abstract)

Publications resulting from this research: 

Carr, T. D. and T. E. Williamson. 2010. Bistahieversor sealeyi gen. et sp. nov., a new tyrannosaur from New Mexico and the origin of deep snouts in Tyrannosauroidea. Journal of Vertebrate Paleontology 30:1-16.

Carr, T. D., T. E. Williamson, B. B. Britt, and K. Stadtman. 2011. A new genus of short-skulled tyrannosaurid from the Upper Cretaceous (upper Campanian) Kaiparowits Formation of Utah. Naturwissenschaften. 98(3):241-246.

Clemens, W. A. and T. E. Williamson. 2005. A new species of Eoconodon (Triisodontidae, Mammalia) from the San Juan Basin, New Mexico. Journal of Vertebrate Paleontology 25:208-213.

D’Emic, M. D.; J. A. Wilson, and T. E. Williamson. 2011. A sauropod dinosaur pes from the latest Cretaceous of North America and the validity of Alamosaurus sanjuanensis. Journal of Vertebrate Paleontology 31:1072-1079.

Evans, D. C., T. E. Williamson, M. A. Loewen, and J. I. Kirkland. 2013. A review of pachycephalosaurid dinosaurs from Grand Staircase-Escalante National Monument, southern Utah. In A. L. Titus and M. A. Loewen (eds.), At the Top of the Grand Staircase: The Late Cretaceous of Southern Utah (Life of the Past), in p. 482-487. Indiana University Press, Bloomington.

Janis, C. M., J. D. Archibald, R. L. Cifelli, S. G. Lucas, C. R. Schaff, R. M. Schoch, and T. E. Williamson. 1998. Archaic ungulates and ungulate-like mammals, pp. 247-259, in C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary Mammals of North America. Cambridge, Cambridge University Press.

Lofgren, D. L., J. A. Lillegraven, W. A. Clemens, P. D. Gingerich, and T. E. Williamson. 2004. Paleocene biochronology of North America: The Puercan through Clarkforkian land mammal ages, Pp. 43-105, In M. O. Woodburne (ed.), The first North American land mammal ages of the Cenozoic Era, University of California Press.

Lucas, S. G., R. M. Schoch, and T. E. Williamson. 1998. Taeniodonta, in C. M. Janis, K. M. Scott, and L. L. Jacobs (eds.), Evolution of Tertiary Mammals of North America. Cambridge, Cambridge University Press.

Lucas, S. G. and T. E. Williamson. 1993a. Late Cretaceous to early Eocene vertebrate biostratigraphy and biochronology of the San Juan Basin, New Mexico.  New Mexico Museum of Natural History and Science, Bulletin 3:93-104.

Lucas, S. G. and T. E. Williamson. 1993b. A new taeniodont from the Paleocene of the San Juan Basin, New Mexico and the phylogeny of the Taeniodonta.  Journal of Mammalogy 74:175-179.

Lucas, S. G. and Williamson, T. E. 1995. Systematic position and biochronological significance of Yuodon and Palasiodon, supposed Paleocene "condylarths" from China. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 196:93-107.

Lucas, S. G., T. E. Williamson, and M. Middleton. 1997. Catopsalis (Mammalia: Multituberculata) from the Paleocene of New Mexico and Utah: taxonomy and biochronological significance.  Journal of Paleontology 71:484-493.

O’Leary, M. A., S. G. Lucas, and T. E. Williamson. 2000. A new specimen of Ankalagon (Mammalia, Mesonychia) and evidence of sexual dimorphism in mesonychians. Journal of Vertebrate Paleontology 20:387-393.

Schott, R., D. Evans, T. E. Williamson, T. Carr, and M. Goodwin. 2009. The anatomy and systematics of Colepiocephale lambei (Dinosauria: Pachycephalosauridae). Journal of Vertebrate Paleontology 29:771-786.

Shimada, K., T. E. Williamson, and P. L. Sealey. 2010. A new gigantic pycnodont fish from the Juana Lopez Member of the Upper Cretaceous Mancos Shale of New Mexico, U.S.A. Journal of Vertebrate Paleontology. 30:598-603.

Silcox, M. T. and T. E. Williamson. 2012. New discoveries of primates from the early Paleocene Nacimiento Formation (Torrejonian NALMA), San Juan Basin, New Mexico. Journal of Human Evolution 63:805-833.

Tanaka, K., D. K. Zelenitsky, T. Williamson, A. Weil, and F. Therrien. 2010. Description of fossil eggshells from the Upper Cretaceous Fruitland Formation (upper Campanian), New Mexico. Historical Biology. 1-15.

Williamson, T. E. 1996. The beginning of the age of mammals in the San Juan Basin, New Mexico: biostratigraphy and evolution of Paleocene Mammals of the Nacimiento Formation.  New Mexico Museum of Natural History Bulletin 8, 141 pp.

Williamson, T. E. and S. L. Brusatte. 2013a. New specimens of the rare taeniodont Wortmania (Mammalia: Eutheria) from the San Juan Basin of New Mexico and comments on the phylogeny and functional morphology of “archaic” mammals. PLoS ONE 8(9): e75886. doi:10.1371/journal.pone.0075886.

Williamson, T. E. and S. L. Brusatte. 2013b. Taxon-character dataset from Williamson and Brusatte (2013a). Morphobank, Project 1045.

Williamson, T. E., S. L. Brusatte, T. D. Carr, A. Weil, and B. R. Standhardt. 2012a. The phylogeny and evolution of Cretaceous-Paleogene metatherians: New cladistic analysis and description of new early Paleocene specimens from the Nacimiento Formation, New Mexico: Journal of Systematic Palaeontology 10:625-651.

Williamson, T. E., S. L. Brusatte, T. D. Carr, A. Weil, and B. R. Standhardt. 2012b. Taxon-Character dataset from Williamson et al. (2012a). Morphobank, Project 682.

Williamson, T. E. and T. D. Carr. 2007. Bomburia and Ellipsodon (Mammalia, Mioclaenidae) from the early Paleocene of New Mexico. Journal of Paleontology 81:966-985.

Williamson, T. E. and T. D. Carr. 2007. Revision of the problematic early Paleocene genus Oxyclaenus (Mammalia: Oxyclaenidae) and a new species of Carcinodon. Journal of Vertebrate Paleontology 27:973-986.

Williamson, T. E., B. S.Kues, G. S. Weissmann, T. A. Stidham, and S. L. Yurchyk. 2009. A Cretaceous feather from the Upper Cretaceous (lower Campanian) Point Lookout Sandstone, San Juan Basin, northwestern New Mexico. Cretaceous Research 30:547-550.

Williamson, T. E. and S. G. Lucas. 1992b. Stratigraphy and mammalian biostratigraphy of the Paleocene Nacimiento Formation, southern San Juan Basin, New Mexico. New Mexico Geological Society, Guidebook 43:265-296.

Williamson, T. E. and S. G. Lucas. 1993a. Paleocene vertebrate paleontology of the San Juan Basin, New Mexico.  New Mexico Museum of Natural History, Bulletin 3:105-136.

Williamson, T. E. and S. G. Lucas. 1993b. Freshwater selachians from the early Paleocene of the San Juan Basin, northwestern New Mexico, USA.  Tertiary Research 14:1-9.

Williamson, T. E. and S. G. Lucas. 1997a. The Chico Springs locality, Nacimiento Formation, San Juan Basin, New Mexico.  New Mexico Geological Society, Guidebook 48:259-265.

Williamson, T. E., D. Nichols, and A. Weil. 2008. Paleocene palynomorph assemblages from the Nacimiento Formation, San Juan Basin, New Mexico. New Mexico Geology 30:3-11.

Williamson, T. E., and L. Taylor. 2011. New species of Peradectes and Swaindelphys (Mammalia; Metatheria) from the early Paleocene (Torrejonian) Nacimiento Formation, San Juan Basin, New Mexico. Palaeontologia Electronica 14.

Williamson, T. E. and A. Weil. 2008a. Therian mammals from the Naashoibito Member, Kirtland Formation, San Juan Basin, New Mexico and their biochronologic and paleobiogeographic significance. Journal of Vertebrate Paleontology 28:803-815.

Williamson, T. E. and A. Weil. 2008b. "Metatherian Mammals from the Naashoibito Member, Kirtland Formation, San Juan Basin, New Mexico and Their Biochronologic and Paleobiogeographic Significance." Journal of Vertebrate Paleontology. Vol. 28(3): 803-815.

Williamson, T. E. and A. Weil. 2011. A new early Paleocene (Puercan) hyopsodontid “condylarth” from New Mexico. Acta Palaeontologica Polonica 56:247-255.

 Williamson, T. E., A. Weil, and B. Standhardt. 2011a. Cimolestids (Mammalia) from the early Paleocene (Puercan) of New Mexico. Journal of Vertebrate Paleontology 31(1):162-180.

Williamson, T. E., A. Weil, and B. Standhardt. 2011a. Taxon-character dataset from Williamson et al. (2011a). Morphobank, Project 496.

Suggested reading:

Alroy, J. 1999. "The fossil record of North American mammals; evidence for a Paleocene evolutionary radiation." Systematic Biology 48(1): 107-118.

Asher, R. J., J. Meng, et al. 2005. "Stem Lagomorpha and the antiquity of Glires." Science 307: 1091-1094.

Bininda-Emonds, O. R. P., M. Cardillo, et al. 2007. "The delayed rise of present-day mammals." Nature 446-512.

Brusatte, S. L., R. J. Butler, et al. 2012. Dinosaur morphological diversity and the end-Cretaceous extinction. Nature Communications 3: 804.

Cope, E. D. 1884. The Vertebrata of the Tertiary formations of the West, Volume III, Tertiary vertebrates, book 1. Washington.

Goswami, A. (2012). A dating success story: Genomes and fossils converge on placental mammal origins. EvoDevo 3: 18.

Hunter, J. P. and C. M. Janis. 2006. "Spiny Norman in the Garden of Eden? Dispersal and early biogeography of Placentalia." Journal of Mammalian Evolution 13: 89-123.

Kues, B. S. 2008. The Paleontology of New Mexico. Albuquerque: University of New Mexico Press. 428 pp.

Matthew, W. D. 1937. Paleocene faunas of the San Juan Basin, New Mexico [edited by Walter Granger, William King Gregory, and Edwin Harris Colbert]. Transactions of the American Philosophical Society, 30(510).

Springer, M. S., E. C. Murphy, et al. 2003. "Placental mammal diversification and the Cretaceous-Tertiary boundary." Proceedings of the National Academy of Sciences 100(3): 1056-1061.

Sullivan, R. M., A. Boere, et al. 2005. "Redescription of the ceratopsid dinosaur Torosaurus utahensis (Gilmore, 1946) and a revision of the genus." Journal of Paleontology 79: 577-595.

Wible, J. R., G. W. Rougier, et al. 2007. "Cretaceous eutherians and Laurasian origin for placental mammals near the K/T boundary." Nature 447: 1003-1006.

Wilson, G.P. Mammals across the K/Pg boundary in northeastern Montana, U.S.A.: Dental morphology and body size patterns reveal extinction selectivity and immigrant-fueled ecospace filling. Paleobiology 39(3):429-469.

Wilson, G.P., A.R. Evans, I.J. Corfe, P.D. Smits, M. Fortelius, and J. Jernvall. Adaptive radiation of multituberculate mammals before the extinction of dinosaurs. Nature 483:457-460.