Professor Jason Head
- Professor of Vertebrate Evolution and Ecology, Curator
Contact
Location
- Museum Room G.20
About
I am group leader of the Vertebrate Palaeontology Group.
I received my BSc in biology from the University of Michigan in 1995, and my PhD in geology (with a concentration in vertebrate paleontology) from Southern Methodist University in 2002. I held a National Science Foundation Postdoctoral Fellowship in Biological Informatics at the Smithsonian Institution and Queen Mary, University of London from 2002-2005, and was faculty at the George Washington University, University of Toronto, and University of Nebraska-Lincoln prior to joining the Department of Zoology in 2015.
Museum- and field studies are fundamental components of my research and teaching. I have 30 years of natural history museum experience ranging from specimen preparation and conservation, database development, public education and outreach, and curation. My field research has covered the Mesozoic and Cenozoic of Africa, the Americas, and South Asia. My current focus is on the tropics, with projects spanning the Palaeocene through Holocene in Colombia, Kenya, Ethiopia, and Indonesia.
Research
I am a broadly-trained vertebrate paleontologist and my research interests align along two axes, one primarily ecological and one primarily evolutionary developmental: 1) the evolution of modern tropical vertebrate clades, focusing on the relationship between fauna and environment during the Paleogene and Neogene; and 2) the evolution of vertebrate body forms and inferring the roles of regulatory genetic networks and novel developmental mechanisms from anatomy of extant and fossil taxa. Although the questions I address and the methods I employ are not taxon-specific, my focus is on reptiles because they are diverse, important components of modern ecosystems, possess a dense fossil record during the last 66 million years, and exhibit extraordinary plasticity in body form and ecophenotype, including axial elongation, limblessness, and the evolution of shells. My work integrates phenomic data, as quantified and qualified skeletal anatomy derived from field and museum studies, with molecular, environmental, and paleoclimate datasets.
The newest component of my research is the integration of ecometric trait data from fossil vertebrates with modern records to help forecast biotic responses to anthropogenic climate change as a component of taxon-free conservation paleobiology. In this work, I collaborate with colleagues from Kenya, Ethiopia, Germany, Finland, France, and the United States.
Key publications:
(*Postgraduate student)
*Roberts, L. E. R. and J. J. Head. 2026. Evolution of the reptile spine reveals independent trajectories to axial skeletal complexity in amniotes. Nature Communications. DOI: 10.1038/s41467-026-72071-x.
Beyene, Y., B. Asfaw, T. D. White, G. WoldeGabriel, R. Bernor, F. Bibi, J. Boisserie, M .F. Brasil, C. A. Brochu, J. P. Carlson, N. G. García, I. X. Giaourtsakis, H. Hailu, W. K. Hart, J. J. Head, L. J. Hlusko, F. Kaya, A. Louchart, S. Melaku, J. Müller, E. M. Niespolo, C. Pehlevan, P. R. Renne, A. Souron, and L. Sánchez-Romero. 2026. Halibee member archaeology: Middle Stone Age environment, technology, and postmortem modifications, Proceedings of the National Academy of Sciences, U.S.A. 123, e2534441123. DOI: 10.1073/pnas.2534441123.
*Parker, A. K., J-R Boisserie, J. Müller, C. A. Brochu and J. J. Head. 2026. Body size histories of Shungura Formation reptiles in biotic and abiotic environmental context. Comptes Rendus Palevol. DOI: 10.31233/osf.io/2p6e3_v3
*Alfonso-Rojas, A. F., J. D. Carrillo-Briceño, R. Sánchez, M. R. Sánchez-Villagra, and J. J. Head. 2025. An early origin of gigantism in anacondas (Serpentes: Eunectes) revealed by the fossil record. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2025.2572967
Benson, R. B. J., S. A. Walsh, E. F. Griffiths, Z. Kulik, J. Botha,V. Fernandez, J. J. Head, and S. E. Evans. 2025. Mosaic anatomy in an early fossil squamate. Nature. DOI: 10.1038/s41586-025-09566-y
Head. J. J. 2025. Chapter 8: Siwalik Reptilia, exclusive of Aves. Pp. 117-135, In C. Badgley, D. Pilbeam, and M. Morgan (eds.), At the foot of the Himalayas: Paleontology and ecosystem dynamics of the Siwalik record of Pakistan. Johns Hopkins University Press, Baltimore. DOI: 10.56021/9781421450278
*Hillan, E. J., L. E. Roberts, K. E. Criswell, and J. J. Head. 2024. Conservation of rib skeleton regionalization in the homoplastic evolution of the snake-like body form in squamates. Proceedings of the Royal Society of London, Series B, 291: 20241160. DOI: 10.1098/rspb.2024.1160
*Jameson, T. J. M., G. R. Johnston, M. Barr, D. Sandow, J. J. Head, and E. C. Turner. 2024. Squamate Scavenging Services: Heath goannas (Varanus rosenbergi) support carcass removal and suppress agriculturally damaging blowflies. Ecology and Evolution. DOI: 10.1002/ece3.11535
*Parker, A. K., J. Müller, J-R Boisserie, and J. J. Head. 2023. The utility of body size as a functional trait to link the past and present in a diverse reptile clade. Proceedings of the National Academy of Sciences, U.S.A. 120(71). DOI: 10.1073/pnas.2201948119
Head, J. J., A. F. C. Howard, and J. Müller. 2022. The first 80 million years of snake evolution: The Mesozoic fossil record of snakes and its implications for origin hypotheses, biogeography, and mass extinction. Pps. 26-55 In D. Gower, and H. Zaher (eds.), The origin and early evolution of snakes, Cambridge University Press, Cambridge.