Australopiths (ape-men)
Various species of australopithecines lived during the Pliocene epoch at numerous sites in eastern, central and southern Africa. Like humans they were bipedal but, like apes, they had small brains.
Australopithecus anamensis (‘southern ape of the lake’), dated at 4.2 mya, found near Lake Turkana, is similar to the better known species, A. afarensis (‘southern ape of Afar’), dated at 3.9-2.9 mya. The most celebrated fossil of A. afarensis, known as ‘Lucy’ (named after the Beatles’ recording being played in the camp at the time), is a partial skeleton of a female discovered by Donald Carl Johanson (1943- ).
One of the first australopithecines to be found Australopithecus africanus (‘southern ape of Africa’), the ‘Taung Child’, dated at 3-2 mya, was recovered from a lime quarry at Taung in southern Africa. In 1925 Raymond Arthur Dart (1893-1988) described it as an early hominin rather than an ape. It was another twelve years before his comments were proved correct when Robert Broom (1866-1951) recovered a further specimen from a limestone cave at Sterkfontein, South Africa.
These australopithecines are described as gracile (‘slender’), and the fossil record seems to indicate that they are the common ancestor to a group of ‘robust’ australopithecines, now called paranthropines (‘beside humans’).
One of the earliest robust Pliocene hominins is Paranthropus aethiopicus, found in Ethiopia in 1968 and dated at 2.7-2.5 mya. In 1985, the famous ‘black skull’ (the colouration was caused by high levels of manganese) was found west of Lake Turkana in Kenya. Its features share many traits with Australopithecus afarensis and thus could be a descendant.
Paranthropus robustus, dated at 2.0-1.2 mya, was discovered in 1938 in southern Africa by Robert Broom. Males may have been about 1.3 metres (4 ft) tall and weighed 54 kg (120 lb); females were less than one metre (3 ft) tall and weighed 40 kg (90 lb). The average brain size was 500 cc, about the size of a chimpanzee’s.
Paranthropus boisei (named after Charles Boise, a backer of the Leakeys), dated at 2.3-1.2 mya, is the largest of the species. When it was first discovered by Mary Douglas Leakey (1913-96) it was nicknamed ‘Nutcracker Man’, named Zinjanthropus (‘Zinj + ape’) boisei, and then Australopithecus boisei before it finally became Paranthropus boisei.
In 1978 at Laetoli in Tanzania, a team directed by Mary Leakey (1913-96) excavated and confirmed evidence of early upright bipedalism – a clear trail of hominin footprints of two adults and a child, impressed and preserved in volcanic ash, dated at 3.7 mya.
Hominans (humans)
Homo habilis (‘handy man’), dated at 2.3-1.4 mya, was named after its apparent connection with the ancient Oldowan industry (2.7-1.6 mya) at Olduvai Gorge. Homo habilis was about 1.5 metres (5 ft) tall and had a relatively large brain (650-800 cc), but was still only about half the size of ours.
Homo rudolfensis, dated at 1.9 mya, was discovered on the east side of Lake Rudolf (now Lake Turkana) by a team led by Richard Erskine Frere Leakey (1944- ). It is not certain if Homo rudolfensis is ancestral to later Homo species.
Homo erectus (1.9-0.1 mya), has been found in Africa, China, Europe, Indonesia and Vietnam. It is thought that H. erectus is a descendant of earlier hominins but it is possible that H. habilis and H. erectus may have had a common ancestor. Over time there seems to have been a steady increase in brain capacity from 850 to 1100 cc. H. habilis was about 1.8 metres (5.9 ft) tall, and much stronger than modern humans.
Most species of H. erectus disappeared from the fossil record around 0.4 mya, but at Ngandong on the Solo River the still robust but more evolved Homo erectus soloensis (Solo River) persisted until 50,000 years ago (50 kya). Elsewhere, H. erectus made room for the evolutionary advances, loosely named ‘archaic’ H. sapiens, that led up to modern man.
In 1907 at Mauer near Heidelberg in Germany, a lower jaw was found and assigned to H. heidelbergensis, dated 600-200 kya. The new species retained the solid build of H. erectus but brain capacity had increased to about 1200 cc.
Homo neanderthalensis, named after the Neander Valley where the first widely accepted remains were discovered in 1856, occupied much of Europe and western Asia during the Late Pleistocene. Signs of the early Neanderthals have been found in sites such as Swanscombe (300 kya), Atapuerca (250
kya) and Ehringsdorf (220 kya). By 125 kya the whole range of Neanderthal characteristics are evident in fossils from sites in France, Italy and Croatia, and by 70 kya ‘classical’ Neanderthals were living in Western Europe.
Their relatively robust stature is thought to be an adaptation to the cold climate of the epoch. Their brain size at 1450-1500 cc was equal to or slightly larger than that of some modern humans. Adult males were about 1.7 metres (5.5 ft) tall and weighed about 70 kg (154 lb).Around 40 kya the Cro-Magnons, named after a site in the Dordogne in southwest France, arrived in Europe. Anatomically, they were much more like the modern human, Homo sapiens (‘wise human’), than were the Neanderthals. It seems that from this time the Neanderthals were gradually marginalised until by c.27 kya they were extinct.
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