Peter S. Ungar (born 1963) is an American paleoanthropologist and evolutionary biologist. He is Distinguished Professor and Director of the Environmental Dynamics Program at the University of Arkansas. Before arriving at Arkansas, he taught at the Johns Hopkins School of Medicine and the Duke University Medical Center.
Ungar is known primarily for his work on the role of diet in human evolution. He has spent thousands of hours observing wild apes and other primates in the rainforest of Latin America and Southeast Asia, studied fossils from tyrannosaurids to Neandertals, and developed new techniques for using advanced surface analysis technologies to tease information about diet from tooth shape and patterns of use wear.
Ungar has written or coauthored more than 150 scientific papers on ecology and evolution for books and journals including Nature, Science, Proceedings of the National Academy of Sciences, and Philosophical Transactions of the Royal Society. These have focused on food choices and feeding in living primates, and the role of diet in the evolution of human ancestors and other fossil species. His book  Mammal Teeth: Origin, Evolution and Diversity won the PROSE Award for best book in the Biological Sciences, and he edited  Evolution of the Human Diet: The Known, the Unknown and the Unknowable] and coedited Human Diet: Its Origins and Evolution. His forays into popular science wrting include  Teeth: A Very Short Introduction, and his most recent trade book, Evolution's Bite: A Story about Teeth, Diet, and Human Origins.
Ungar’s work has been featured in hundreds of electronic, print, and broadcast media outlets, and he appeared recently in documentaries on the Discovery Channel, BBC Television, and the Science Channel.
- Ungar, P.S.; Grine, F.E.; Teaford, M.F. (2008). "Dental microwear indicates that Paranthropus boisei was not a hard-object feeder". PLoS ONE. 3 (4): e20441.
- Ungar, P.S. (2008). "Strong teeth, strong seeds". Nature. 452: 703–705. doi:10.1038/452703a.
- Ungar, P.S.; Grine, F.E.; Teaford, M.F. (2006). "Diet in early Homo: A review of the evidence and a new model of adaptive versatility". Annual Review of Anthropology. 35: 209–228. doi:10.1146/annurev.anthro.35.081705.123153.
- Scott, R.S.; Ungar, P.S.; Bergstrom, T.S.; Brown, C.A.; Grine, F.E.; Teaford, M.F.; Walker, A. (2005). "Dental microwear texture analysis reflects diets of living primates and fossil hominins". Nature. 436: 693–695. doi:10.1038/nature03822.
- Ungar, P.S. (2004). "Dental topography and diets of Australopithecus afarensis and early Homo". Journal of Human Evolution. 46: 605–622. doi:10.1016/j.jhevol.2004.03.004.
- Ungar, P.S. Evolution's Bite: A Story of Teeth, Diet, and Human Origins. 2017. ISBN 9781400884759
- Scott, R.S.; Ungar, P.S.; Bergstrom, T.S.; Brown, C.A.; Grine, F.E.; Teaford, M.F.; Walker, A. Dental microwear texture analysis reflects diets of living primates and fossil hominins. Nature, 436: 693-695, 2005.
- Ungar, Peter S. "Quantification of Dental Microwear by Tandem Scanning Confocal Microscopy and Scale-Sensitive Fractal Analyses". Scanning. 25: 185–193. doi:10.1002/sca.4950250405.