French paleontologist and Jesuit priest Pierre Teilhard de Chardin is remembered as someone who deviated from theology to science. He discovered the fossilized remains known as the Peking man in China, but faced a lot of opposition from his religious superiors when it came to publishing his scientific thoughts.
Alcide d'Orbigny is regarded as the founder of micropaleontology. The French paleontologist traveled for 8 years throughout South America, exploring its natural history and geology. His study of marine fossils, sedimentary rocks, and pollen was accompanied by his iconic written work Paléontologie française. He supported the theory of catastrophism.