One could easily imagine that it came as a nasty shock to the public when Georges Cuvier presented his paper on living and fossilized elephants in 1796. The paper demonstrated that woolly mammoths constituted a distinct, and indeed extinct, species, rather than the preserved remains of African or Indian elephants that had migrated to the tropics because of cooling climate.
This hardly jived with the thinking of the day, that God's creation was perfect, and that no species could ever go extinct. But apparently, Cuvier was not satisfied with the damage he had already done. He became increasingly convinced that most of the fossils he studied where of extinct creatures.
Cuvier contended that earth had gone through a number of periods, characterized by different faunas, and separated by a series of cataclysmic natural disasters. He postulated that, since a great number of species would be wiped out by an extinction, or "revolution," as he referred to them, a creation event must follow each extinction.
This view rose out of his opposition to the evolutionary theory proposed by his colleague at the Académie des Sciences, Jean-Baptiste Lamarck. His view was later championed by Richard Owen, of the British Museum of Natural History, after Darwin published Origin of Species.
Anti-evolution views aside, Cuvier is notable for first asserting that extinction existed as a phenomena, and thus virtually founding the modern study of paleontology. He also suggested that there had been a time when reptiles were the dominant group on earth, an idea confirmed by the discoveries of the next century.