The more scientists dig, the more hominid species they find. Most are distant cousins that went extinct without progeny; others are our direct ancestors
1 Ardipithecus ramidus
WHEN SPECIES LIVED 4.4 million years ago
FIRST DISCOVERED Aramis, Ethiopia
COMMENT Exactly where this primitive species belongs and whether it walked upright are still unknown
2 Australopithecus anamensis
[WHEN SPECIES LIVED] 4.2 million to 3.9 million years
[FIRST DISCOVERED] Kanapoi, Kenya
[COMMENT] Shows that our ancestors walked upright at least 500,000 years earlier than previously known
3 A. afarensis
[WHEN SPECIES LIVED] 3.6 million to 2.9 million years
[FIRST DISCOVERED] Laetoli, Tanzania
[COMMENT] To date, found only in eastern Africa. Most famous example is the 3.2 million-year-old partial skeleton known as Lucy
4 A. africanus
[WHEN SPECIES LIVED] 3 million to 2.3 million years
[FIRST DISCOVERED] Taung, South Africa
[COMMENT] First ancient human ancestor discovered in Africa, it was once thought to be the missing link between apes and humans
5 A. aethiopicus
[WHEN SPECIES LIVED] 2.8 million to 2.3 million years
[FIRST DISCOVERED] Omo Basin, Ethiopia
[COMMENT] May be an ancestor of A. boisei and A. robustus. The fossil above, found by Richard Leakey's team, is called the Black Skull
6 A. garhi
[WHEN SPECIES LIVED] 2.5 million years
[FIRST DISCOVERED] Bouri, Ethiopia
[COMMENT] The newest hominid species to be identified, H may have been the first to use stone tools and eat meat
7 A. boisei
[WHEN SPECIES LIVED] 2.3 million to 1.4 million years
[FIRST DISCOVERED] Olduvai Gorge, Tanzania
[COMMENT] First ancient hominid found by the Leakeys. This skull's huge molars earned it the nickname "Nutcracker Man"
8 A. robustus
[WHEN SPECIES LIVED] 1.9 million to 1.5 million years
[FIRST DISCOVERED] Kromdraai, South Africa
[COMMENT] Discovered by Robert Broom in 1938, it is found only in southern Africa and is not a direct human ancestor
9 Homo rudolfensis
[WHEN SPECIES LIVED] 2.4 million to 1.8 million years
[FIRST DISCOVERED] Koobi Fora, Kenya
[COMMENT] May be an early form of H. habilis; if a distinct species, it's the earliest known member of our genus
10 H. habilis
[WHEN SPECIES LIVED] 1.9 million to 1.6 million years
[FIRST DISCOVERED] Olduvai Gorge, Tanzania
[COMMENT] Unearthed by the Leakeys in the early 1960s, "Handy Man" was once thought to be the earliest tool user
11 H. ergaster
[WHEN SPECIES LIVED] 1.7 million to 1.5 million years
[FIRST DISCOVERED] Koobi Fora, Kenya
[COMMENT] May be an early form of H. erectus found only in Africa; its designation as a separate species is debated
12 H. erectus
[WHEN SPECIES LIVED] 1.7 million to 250,000 years
[FIRST DISCOVERED] Trinil, Indonesia
[COMMENT] Discovered in 1891, it may have been the first hominid to use fire and the first to migrate out of Africa