Jean Léopold Nicolas Frédéric, baron Cuvier (23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in natural sciences research in the early 19th century and was instrumental in establishing the fields of comparative anatomy and paleontology through his work in comparing living animals with fossils.
Cuvier's work is considered the foundation of vertebrate paleontology, and he expanded Linnaean taxonomy by grouping classes into phyla and incorporating both fossils and living species into the classification. Cuvier is also known for establishing extinction as a scientific fact—at the time, extinction was considered by many of Cuvier's contemporaries to be merely controversial speculation. In his Essay on the Theory of the Earth (1813), Cuvier proposed that now-extinct species had been wiped out by periodic catastrophic flooding events. In this way, Cuvier became the most influential proponent of catastrophism in geology in the early 19th century.