Thomas E. Williamson, Ph.D.

Curator of Paleontology

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Website: Thomas E. Williamson's Research Website


Dr. Thomas Williamson's research activities focus on Late Cretaceous and Paleogene vertebrate fossils and the geological record to better understand the evolutionary history of certain groups of animals and how terrestrial vertebrate communities have changed over time. This is a dynamic time in earth's history that includes the end-Cretaceous mass-Extinction and the explosive radiation of mammals that followed. New Mexico contains one of the most complete records of Late Cretaceous through early Paleocene terrestrial ecosystems.  

Dr. Williamson is engaged in collaborative, interdisciplinary research based on the geological and paleontological record preserved in the San Juan Basin of northwestern New Mexico. He was recently (September, 2013) awarded a 3-year grant from the National Science Foundation "Testing the link between climate and mammalian faunal dynamics in the early Paleocene record of the San Juan Basin, New Mexico." This collaborative project involves scientists from the University of Edinburgh (Dr. Stephen Brusatte), Baylor University (Drs. Dan Peppe, Stacy Atchley, and Lee Nordt), and the University of Nebraska-Lincoln (Dr. Ross Secord) and will study how climate may have influenced mammal communities through the first four million years of the Paleocene. Other workers involved with this project include Dr. Anne Weil (Oklahoma State University), an expert on multituberculate mammals, and Dr. Matt Heizler (New Mexico Tech), a geochronologist. Dr. Williamson and his colleagues have also received support for research from the U.S. Bureau of Land Management (including the National Landscape Conservation System and the National America Great Outdoor Fund).

Dr. Williamson is also engaged in a number of cooperative research activities that include looking at the taxonomy, anatomy, and genealogy of certain groups of animals including tyrannosaurian and pachycephalosaurian dinosaurs and metatherian and "condylarthran" mammals. He and his colleagues, including Thomas Carr (Carthage College), Anne Weil (Oklahoma State University), and Stephen Brusatte (University of Edinburgh) continue to work on several long-term projects that examine the taxonomy and evolutionary history of several groups of animals including dinosaurs and mammals. 


Selected Recent Publications


Brusatte, S. L., R. J. Butler, P. M. Barrett, M. T. Carrano, D. C. Evans, G. T. Lloyd, P. D. Mannion, M. A. Norell, D. J. Peppe, P. Upchurch, P., T. E. Williamson. 2014, The extinction of the dinosaurs. Biological Reviews. DOI: 10.1111/brv.12128.

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. 

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.

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.

Williamson, T. E. and S. L. Brusatte. 2013. 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. 2014. Small theropod teeth from the Late Cretaceous of the San Juan Basin, northwestern New Mexico and their implications for understanding latest Cretaceous dinosaur evolution. PLoS ONE. 9(4): e93190

Williamson, T. E., S. L. Brusatte, T. D. Carr, A. Weil, and B. R. Standhardt. 2012. 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, R. Secord, and S. Shelley. 2015. A new taeniolabidoid multituberculate (Mammalia) from the middle Puercan of the Nacimiento Formation, and a revision of taeniolabidoid systematics and phylogeny. Zoological Journal of the Linnean Society. DOI: 10.1111/zoj.12336

Williamson, T. E., S. L. Brusatte, and G. P. Wilson. 2014. The origin and early evolution of metatherian mammals: the Cretaceous record. ZooKeys 465:1-76. DOI: 10.3897/zookeys.465.8178.

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. 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. 2011. Cimolestids (Mammalia) from the early Paleocene (Puercan) of New Mexico. Journal of Vertebrate Paleontology 31(1):162-180.