Brongniart, Alexandre (1770–1847)

French naturalist and geologist who first used fossils to date strata of rock and was the first scientist to arrange the geological formations of the Tertiary period in chronological order. He also wrote Essay on the Classification of Reptiles (1800), splitting reptiles into four orders: Batrachia (now a separate class, Amphibia), Chelonia, Ophidia, and Sauria.

Brongniart introduced the idea of geological dating according to the distinctive fossils found in each stratum. From 1804–11, Brongniart and Georges Cuvier studied the fossils deposited in the Paris basin and showed that the fossils had been laid down during alternate fresh and salt water conditions.

Brongniart was born in Paris and was appointed professor of natural history at the Ecole Centrale des Quatre-Nations, Paris 1797. From 1800 until his death 1847, he was the director of the Sèvres porcelain factory and under his directorship the factory became one of the world leaders in enamelling. In 1822, he became professor of mineralogy at the National Museum of Natural History, Paris.