The older the layers, the more each of them is uniform over a great extent; the newer the layers, the more they are limited and subject to variation within small distances.

Cuvier regularly attended meetings held at the nearby town of Valmont for the discussion of agricultural topics. However his position was usually confused as being polygenist (some writers who have studied his racial work have dubbed his position as "quasi-polygenist") and most of his racial studies have influenced scientific racialism. It was a major development in the history of paleontology and the history of geology.

His most famous work is Le Règne Animal (1817; English: The Animal Kingdom). He is well known for establishing extinction as a fact being the most influential proponent of catastrophism in geology in the early 19th century and opposing the evolutionary theories of Jean-Baptiste de Lamarck and Geoffroy Saint-Hilaire. Jean Léopold Nicolas Frédéric Cuvier (August 23 1769 – May 14 1832) known as Georges Cuvier was a French naturalist and zoologist.