Hominins of The Later Pliocene and Early Pleistocene

Hominins of The Later Pliocene and Early Pleistocene Epochs Australopithecus and Paranthropus Pliocene Epoch 5. 3 – 2. 6 mya Pleistocene 2. 6 – 11, 700 years ag.

Cradle of Humankind

Australopithecus africanus • Raymond Dart and the Taung child • Discovered in 1924. Estimated to have been 3 years old at death.

A. africanus facts • Males were 4’ 6” tall on average and weighed 90 lbs. • Females were 3’ 9” tall and weighed 66 lbs. • Cranial volume averaged 442 cc. • The species is estimated to have existed from 3. 3 - 2. 2 million years ago. • Though fossils come predominantly from South Africa, the species is thought to have ranged in East Africa as well.

Robert Broom Fired from the University of Stellenbosch for teaching evolution. Started work at Sterkfontein in 1936 at age 70, where he found A. africanus fossils, including “Mrs. Ples”

• Sts 5 “Mrs. Ples” Sterkfontein Australopithecus africanus • Sk 48 Swartkrans Paranthropus robustus Discovered in 1948

Swartkrans has yielded the remains of 124 P. robustus individuals and remains of 5 members potentially of Homo ergaster. Dates of the cave deposits range from c. 1. 9 mya to 11, 000 years ago, putting the deposits in the Pleistocene epoch. Some of the dates are derived by thermoluminescence dating of quartz sands. A metatarsal of the big toe of P. robustus shows that it had lost all opposability. Average brain size: 530 cc.

Excavations at Drimolen 2. 04 – 1. 95 mya

Most complete female Paranthropus robustus cranium

Australopithecus sediba • Discovered by Lee Berger in 2008. • Dates to 1. 97 mya (Pleistocene epoch).

Fig. 1 Maximum parsimony cladogram of gorilla outgroup and nine hominin samples based on ASUDAS characters. Numbers are from a separate, although analogous 50% majority consensus tree of 10, 000 bootstrapped replicate data sets; they represent the proportion of included trees that support the given node. Late date suggests it may have been contemporary with early Homo. J D Irish et al. Science 2013; 340: 1233062 Published by AAAS

Mosaic anatomy

Sediba has: • Limb proportions similar to a modern human and similar hands. • A scapula similar in shape to Pongo, and shoulder harness position similar to an apes’, suggests habitual tree climbing. • A conical rib cage. • Foot and legs suggests hyperpronation (rolling foot to the inside) when walking.

Fig. 2 Hyperpronation. (A) The pedal bones of Au. sediba are superimposed on a human foot in dorsal view. J M De. Silva et al. Science 2013; 340: 1232999 Published by AAAS

Paranthropus boisei

Discovered by Mary Leakey in 1959 in Olduvai Gorge, Tanzania; Date: 1. 8 MYA (Pleistocene epoch)

Post-orbital constriction Temporal fossae

Paranthropus aethiopicus KNM-WT-17000 Found in 1985 Date: 2. 5 MYA

Australopithecus garhi Discovered in 1999 in the Afar Triangle by Berhane Asfaw. Date: 2. 5 mya.