Simplify the following text for a Grade 9 native English-speaking person.
Original: Louis Seymour Bazett Leakey ( L.S.B. Leakey ) ( August 7 , 1903 â `` October 1 , 1972 ) was a Kenyan archaeologist and naturalist whose work was important in establishing human evolutionary development in Africa .
Simplified: Louis Leakey ( L.S.B. Leakey , 7 August 1903 â `` 1 October 1972 ) was a Kenyan archaeologist , anthropologist and naturalist .