Jason A. Lillegraven was a professor of geology and geophysics at the University of Wyoming from the 1970’s into the early 2000’s. He extensively studied paleontology and zoology, among many other subjects. Lillegraven earned a bachelor’s degree in biology and went on to study anatomy, embryology, genetics, and vertebrate paleontology at Long Beach State, and later earned his master's degree in paleontology at the South Dakota School of Mines and his doctorate at the University of Kansas in zoology. Before beginning at the University of Wyoming, Lillegraven studied at the University of California Berkeley and earned his first faculty position teaching zoology at San Diego State. He worked in the zoology and geology departments at the University of Wyoming, two divisions of the National Science Foundation, and studied paleontology at the Free University of Berlin in Germany. Following retirement from the University of Wyoming in 2004, Lillegraven continued to contribute to the university through field research and co-editing Rocky Mountain Geology.