George Gaylord Simpson summary

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George Gaylord Simpson, (born June 16, 1902, Chicago, Ill., U.S.—died Oct. 6, 1984, Tucson, Ariz.), U.S. paleontologist. He earned a doctorate at Yale University. His contributions to evolutionary theory include a detailed classification of mammals, based on his studies of mammalian evolution, which is still the standard. He also is known for his studies of intercontinental migrations of animal species, especially South American mammals, in past geologic times. His books include Tempo and Mode in Evolution (1944; 1984), The Meaning of Evolution (1949), The Major Features of Evolution (1953), and The Principles of Animal Taxonomy (1961).

fossil Summary

Fossil, remnant, impression, or trace of an animal or plant of a past geologic age that has been preserved in Earth’s crust. The complex of data recorded in fossils worldwide—known as the fossil record—is the primary source of information about the history of life on Earth. Only a small fraction of

Cenozoic Era Summary

Cenozoic Era, third of the major eras of Earth’s history, beginning about 66 million years ago and extending to the present. It was the interval of time during which the continents assumed their modern configuration and geographic positions and during which Earth’s flora and fauna evolved toward

Mesozoic Era Summary

Mesozoic Era, second of Earth’s three major geologic eras of Phanerozoic time. Its name is derived from the Greek term for “middle life.” The Mesozoic Era began 252.2 million years ago, following the conclusion of the Paleozoic Era, and ended 66 million years ago, at the dawn of the Cenozoic Era.

taxonomy Summary

Taxonomy, in a broad sense the science of classification, but more strictly the classification of living and extinct organisms—i.e., biological classification. The term is derived from the Greek taxis (“arrangement”) and nomos (“law”). Taxonomy is, therefore, the methodology and principles of