[close] Jean Léopold Nicolas Frédéric, Baron Cuvier (1769 – 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 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. His study of the strata of the Paris basin with Alexandre Brongniart established the basic principles of biostratigraphy.

Among his other accomplishments, Cuvier established that elephant-like bones found in the USA belonged to an extinct animal he later would name as a mastodon, and that a large skeleton dug up in Paraguay was of Megatherium, a giant, prehistoric ground sloth. He named the pterosaur Pterodactylus, described (but did not discover or name) the aquatic reptile Mosasaurus, and was one of the first people to suggest the earth had been dominated by reptiles, rather than mammals, in prehistoric times.