The Dechronization of Sam Magruder

The Dechronization of Sam Magruder is one of the stranger works of fiction that has appeared in recent years. Its author, George Gaylord Simpson, was widely regarded as the greatest paleontologist of the twentieth century. He died in 1984, but the manuscript of this intriguing novella about a twenty-second-century scientist was not found by his daughter until ten years after his death.
Did Simpson want this time-travel story eventually to be published? Was Sam Magruder Simpson's alter ego, the scientist of his imagination who was able to observe dinosaurs the way they really were?
No one will ever be sure of these answers, but what we do know is that Sam Magruder, a fortyish research chronologist, vanished on February 30, 2162, as he was working on a problem of quantum theory. Thrown back in time eighty million years to the prehistoric Jurassic era, Magruder, endowed with the intelligence of a modern man, discovers that he is the only human being in a valley filled with dinosaurs. Magruder, inventive and resourceful, keeps a stone-slab diary and struggles mightily to survive by feeding on lizards and scrambled turtle eggs, even as menacing tyrannosaurs try to gnaw off his limbs.