From Science Forum:
Told strongly in the Wellisan tradition, and highly reminiscent of Wells' own The Time Machine, George Gaylord Simpson's The Dechronization of Sam Magruder is probably something that Wells himself would be envious of. Simpson was a very well known evolutionist who helped advance that science considerably during his life. He also apparently was a fan of SF, and in addition to a number of scientific tomes, managed to squeeze in a single SF novelette sometime during his life.
At a party one evening after the year 2162 a number of people gathered, among them the Universal Historian, who told a tale of a chronologist, Magruder, who succeeded in separating himself from the present, and launching himself backwards in time. Present also were a few others, including the Ethnologist, the Pragmatist, the Common Man, and several others, all of whom were referred to generically. The Universal Historian promised them all a fantastic tale, and urged them to return the next week to the next get-together to hear the tale. I told you it was done in a strongly Wellsian style, did I not? Simpson did a magnificent job with the technologies in his story, though the bit on time travel was not with out its problems. Simpson created an odd system where the present and the past were two distinct universes, and to travel between the two required immense amounts of energy. As it happened Magruder, a chronologist, was trying to create a laboratory experiment to learn about the difference between the two universes, and accidentally sent himself eighty million years into the past. After the set up by the Universal Historian Simpson switches to descriptions of seven tablets created by Magruder which had recently been discovered stowed in his cave eighty million years prior. The bulk of the book dealt with two issues: Simpson's survival strategies, and finding answers to all those nagging little questions about dinosaurs that will never be answered by the fossil record.
More here. (Note: As an oncologist, I am the privileged witness to a variety of survival strategies in my cancer patients on a daily basis, and no book of fact or fiction has depicted the utter loneliness and infinite dignity of such a struggle better than this slim work of fiction. I urge everyone to read it.)