George Gaylord Simpson (June 16, 1902 – October 6, 1984) was an Americanpaleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the modern evolutionary synthesis, contributing Tempo and mode in evolution (1944), The meaning of evolution (1949) and The major features of evolution (1953). He was an expert on extinctmammals and their intercontinental migrations. He anticipated such concepts as punctuated equilibrium (in Tempo and mode) and dispelled the myth that the evolution of the horse was a linear process culminating in the modern Equus caballus. He coined the word in 1940, and published extensively on the taxonomy of fossil and extant mammals. Simpson was influentially, and incorrectly, opposed to Alfred Wegener's theory of continental drift.