The Dechronization of Sam Magruder

This lost novella by the century's most renowned paleontologist has been called the greatest time-travel story in more than one hundred years.
Vanishing from Earth on February 30, 2162, while working on a problem of quantum theory, research chronologist Sam Magruder is thrown back 80 million years in time. Endowed with the intelligence of a twenty-second-century man, Magruder struggles to survive, feeding on scrambled turtle eggs and diligently recording his observations on a stone-slab diary, even as menacing tyrannosaurus try to gnaw off his limbs.
Filled with magnificent descriptions of the dinosaurs as only Simpson himself could render them, "The Dechronization of Sam Magruder "is not only a classic time-travel tale but a philosophical work that astutely ponders the complexities of human existence and achievement.