All In The Family:

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

13 H. antecessor

[WHEN SPECIES LIVED] 800,000 years

[FIRST DISCOVERED] Gran Dolina, Spain

[COMMENT] May be the last common ancestor of both Neanderthals and modern humans; species designation debated

14 H. neanderthalensis

[WHEN SPECIES LIVED] 200,000 to <30,000 years

[FIRST DISCOVERED] Neander Valley, Germany

[COMMENT] Overlapped with H. sapiens. Earlier forms extending back to 600,000 years are sometimes called H. heidelbergensis

15 Homo sapiens

Earliest known fossils date to about 100,000 years ago. Other fossils from Africa that are between about 1 million and 100,000 years old probably include ancestors of modern humans