Ardipithecus ramidus 4.4 mya (Another branch or root of all hominoids)

New Genus = New Species

Ardi

Ardipithecus

1. Well adapted bi-ped

Ardipithecus

1. Well adapted bi-ped

2. Foramen magnum positioned further centered

Ardipithecus

1. Well adapted bi-ped

2. Foramen magnum positioned further centered

3. Thin enamel Caps on molars in contrast to earlier hominids

Ardipithecus

1. Well adapted bi-pedal

2. Foramen magnum positioned further centered

3. Thin enamel Caps on molars in contrast to earlier hominids

4. More heavily Forested area as opposed to grasslands savanna

Ardipithecus

1. Well adapted bi-pedal

2. Foramen magnum positioned further centered

3. Thin enamel Caps on molars in contrast to earlier hominids

4. More heavily Forested area as opposed to grasslands savanna

Australopiths (4.2–1.2 mya)• The best-known, most widely distributed, and most

diverse of the early African hominins are colloquially called australopiths.

• This group of hominins is made up of two closely related genera: Australopithecus and Paranthropus.

• These hominins have an established time range of over 3 million years, stretching back as early as 4.2 mya and not becoming extinct until apparently close to 1 mya.

Australopiths (4.2–1.2 mya)• Major features

1.They are all bipedal (although not necessarily identical to Homo in this regard).

2.They all have relatively small brains (i.e., at least compared to Homo).

3.They all have large teeth, particularly the back teeth, with thick to very thick enamel on the molars.

Australopithecus 4.2-1 million

Longest enduring hominoid

Australopithecus 4.2-1 million

Longest enduring hominoidFound in all major geographical regions of Africa,

Australopithecus 4.2-1 million

Longest enduring hominoidFound in all major geographical regions of Africa,

Possibly 8 speciesOR2 genera Paranthropus and Australopithecus

Australopithecus 4.2-1 million

Longest enduring hominoidFound in all major geographical regions of Africa,

Possibly 8 speciesOR2 genera Paranthropus and Australopithecus

•All clearly Bipedal•All have relatively small brains•All have large teeth, w/thick enamel

Lucy 3.7 –3.5 mya

Don Johanson Dicovered in Hadar in 1974

Lucy in combination w/ Leakey footprints tell us about locomotion and stature

Lucy 40% of skeleton, one of three most complete, Pre-100,000

Accurate Dates due to Volcanic Ash layers

Laetoli (Ash Footprints)

Discovered in 1978

1. Convergent Big Toe

2. Clearly Bipedal

3. Arch

4. Slow Moving “Strol”

5. Short Stride

Laetoli (Ash Footprints)

Later More Derived Australopiths (2.5–1.2 mya)

• As they adapted to niches, australopiths became more derived and showed physical changes making them distinct from their immediate ancestors.

• There were at least three separate lineages of hominins living between 2.5 and 1 mya. – Australopithecus– Paranthropus– Homo• Habilis• Erectus• Floriensis (The hobbitt)?