Portrait of George Cuvier, naturalist, comparative anatomist and palaeontologist (23 August 1769 - 13 May 1832). Portrait engraving by James Thompson, issued by Mackenzie Glasgow around 1833 with later hand colouring after painting 'in the possession of Baroness Cuvier'. Cuvier was a giant in the science of the late 18th and early 19th century. His formidable reputation for identifying animals on the basis of few remains made him an authority in the new science of paleontology. He described the first prehistoric reptiles, a pterosaur from Bavaria and a large Mosasaur from Maastricht. His speculation was that there had been an age of the reptiles, (though he at first misidentified Mantell's iguanodon). He pioneered the idea of extinction and believed the world had been subject to catastrophic revolutions that had replaced whole faunas. He did not find evidence for evolution, and opposed the idea.