Homo ergaster
Numerous other researchers have made important discoveries in eastern Africa. Possibly the most famous is the Lucy skeleton, discovered in 1973 by Donald Johanson and Maurice Taieb in Ethiopia's Afar Triangle at the site of Hadar. On the basis of this skeleton and subsequent discoveries, the researchers came up with a new species, "Australopithecus afarensis". In 1975, Colin Groves and Vratislav Mazák announced a new species of human they called "Homo ergaster". "Homo ergaster" specimens have been found at numerous sites in eastern and southern Africa. In 1994, Tim D. White announced a new species, "Ardipithecus ramidus", based on fossils from Ethiopia.