Donald Ross Prothero (February 21, 1954) is an American geologist, paleontologist, and author who specializes in mammalian paleontology and magnetostratigraphy, a technique to date rock layers of the Cenozoic era and its use to date the climate changes which occurred 30-40 million years ago.
Donald Prothero has taught college geology and paleontology for 40 years at Caltech, Columbia among others. He earned his B.A. in geology and biology from the University of California Riverside in 1976, and his M.A. (1978), M.Phil. (1979), and Ph.D. (1982) in geological sciences from Columbia University.
He is the author of 48 books and over 330 scientific papers, mostly on the evolution of fossil mammals (especially rhinos, camels, and horses) and on using the earth's magnetic field changes to date fossil-bearing strata. He has also been on the editorial boards of journals such as Geology, Paleobiology, Journal of Paleontology, and Skeptic magazine.
In 1991 he received the Schuchert Award for outstanding paleontologist under the age of 40 and in 2013 the Shea Award for outstanding writing in the geosciences. In 2015 he received the Joseph T. Gregory Award for service to vertebrate paleontology and in 2016, he received the "Friend of Darwin" award from the National Center for Science Education.
He has been featured on numerous TV documentaries, including Paleoworld, Walking with Prehistoric Beasts, Prehistoric Monsters Revealed, Monsterquest, Prehistoric Predators: Entelodon and Hyaenodon, Conspiracy Road Trip: Creationism, as well as Jeopardy!