Louis Antoine Marie Joseph Dollo (Dec. 7, 1857 – April 19, 1931) was a French vertebrate paleontologist who stated Dollo's Law of Irreversibility whereby in evolution an organism never returns exactly to its former state such that
complex structures, once lost, are not regained in their original form. (While generally true, some exceptions are known.)He began as an assistant (1882), became keeper of mammals (1891) at the Royal Museum of Natural History in Brussels where he stayed most of his life. He was a specialist in fossil fishes, reptiles, birds, and their palaeoecology. He supervised the excavation of the famous, multiple Iguanodons found in 1878 by miners deep underground, at Bernissart, Belgium. image
