The 51-year-old actor is set to lead the biopic, playing a paleo-archaeologist named Richard Leakey who fought elephant poachers in the 1980s in Kenya, reported The Wrap.
Pitt and Jolie first worked together in 'Mr and Mrs' Smith'. Most recently, they collaborated as actor/director in 'By the Sea'. The drama which centers on a couple in the 1970s is possibly set for release later this year.