Paran­thro­pus robus­tus lived in the Cra­dle of Humankind from about 2.5-million to 1-mil­lion years ago. It had huge jaws for chew­ing tough veg­e­ta­tion like roots and tubers. It was not a direct ances­tor of humankind, but an ancient cousin.

Paran­thro­pus finds

Paranth

An artist’s impres­sion of Paran­thro­pus

In 1948, Dr Robert Broom, direc­tor of the Trans­vaal Muse­um, and his assis­tant palaeon­tol­o­gist, John Robin­son, dis­cov­ered a con­cen­tra­tion of Paran­thro­pus fos­sils at Swartkrans, in the Cra­dle of Humankind. The site became world famous as the place where the strange, flat-faced and mas­sive-jawed hominids had lived near­ly 2-mil­lion years ago. Lat­er, Dr Bob Brain, a zool­o­gist and palaeon­tol­o­gist, who like Broom, also became direc­tor of the Trans­vaal Muse­um, exca­vat­ed the site and found even more Paran­thro­pus spec­i­mens. He also found stone tools and evi­dence of the con­trolled use of fire – but these appear to be asso­ci­at­ed with ear­ly mem­bers of the more advanced genus Homo, which also pop­u­lat­ed the site.

Sev­er­al oth­er Paran­thro­pus dis­cov­er­ies have been made with­in the Cra­dle of Humankind. Some Paran­thro­pus teeth were exca­vat­ed from Sterk­fontein Mem­ber 5, a large Paran­thro­pus tooth was also recov­ered from Gon­do­lin, a crushed Paran­thro­pus face from Cooper’s, and a large num­ber of Paran­thro­pus spec­i­mens from Drimolen.

Fos­sils of the same Paran­thro­pus genus, but of sev­er­al species oth­er than robus­tus, have been dis­cov­ered in East Africa since Broom’s ground­break­ing find. Paran­thro­pus aethiopi­cus, dis­cov­ered and named by Camille Aram­bourg and Yves Cop­pens in 1967, lived in the Omo Val­ley of Ethiopia 2.5-million years ago. The first spec­i­men of anoth­er species, Paran­thro­pus boi­sei, was found by Mary Leakey in 1959 at Oldu­vai Gorge in Tan­za­nia. Addi­tion­al Paran­thro­pus boi­sei fos­sils have been found in Pen­inj, Tan­za­nia, and at Chesowan­ja and Lake Turkana in Kenya.

What hap­pened to Paran­thro­pus?

Paran­thro­pus was well adapt­ed to a spe­cialised, main­ly veg­e­tar­i­an, diet. As envi­ron­men­tal con­di­tions changed it there­fore may have been unable to adapt to changes in the avail­able food. Or it may have been wiped out by a species-spe­cif­ic dis­ease. Its decline to extinc­tion also may have been has­tened by the pres­ence of a com­peti­tor, the ear­ly species of the genus Homo.Homo habilis, one of the first hominids in the Homo lin­eage, was more adapt­able and omniv­o­rous, and devel­oped the facil­i­ty to make stone tools. Homo habilis sur­vived, while Paran­thro­pus, which was not a tool-mak­er, became extinct about 1-mil­lion years ago.

Why is Paran­thro­pus impor­tant to our under­stand­ing of evolution?

Paran­thro­pus dis­cov­er­ies at the Cra­dle of Humankind sig­nalled a major shift in think­ing about evo­lu­tion. It became clear that human evo­lu­tion was not a sin­gle chain of adap­ta­tions – it was more like a tree or bush of par­al­lel lin­eages. Some lin­eages were suc­cess­ful, or able to adapt to chang­ing envi­ron­ments, while oth­ers were not and became extinct. The term Paran­thro­pus means par­al­lel to human”, as these hominids walked upright and lived at about the same time as our direct pre­de­ces­sors in the Homo genus, Homo habilis and Homo ergaster.

What did Paran­thro­pus look like?

Paranthropus Boisei

Paran­thro­pus boisei

Paran­thro­pus was a rel­a­tive­ly small, but pow­er­ful­ly built hominid that aver­aged 1.1 to 1.4 m (37” to 47”) in height, weighed between 32 and 50 kg (70 to 110 lb), and had a brain size less than half that of the aver­age mod­ern human. The males were notably larg­er and heav­ier than the females.

Paran­thro­pus’ face and jaw were built for eat­ing tough veg­e­ta­tion. Its large, thick­ly enam­elled molars would have been able to grind the tough­est berries and tubers.

The impor­tance of Paran­thro­pus

The dis­cov­ery of the first Paran­thro­pus robus­tus at Krom­draai in 1938 helped change the way anthro­pol­o­gists saw the evo­lu­tion of humankind.

The flat-faced Paran­thro­pus exist­ed in South and East Africa from about 2.5-million to 1-mil­lion years ago. Its large jaws and teeth were adapt­ed to grind­ing tough food such as roots, hard seeds and berries.

An off­shoot of the lin­eage lead­ing to human­i­ty, it was not a direct ances­tor, but more like a dis­tant cousin. With the dis­cov­ery of Paran­thro­pus, sci­en­tists realised that the evo­lu­tion­ary path to mod­ern humankind was not a sim­ple sequence in which one set of human ances­tors evolved over time, in a neat chain of pro­gres­sion. It is a com­pli­cat­ed – and still con­test­ed – fam­i­ly tree, with many branch­es break­ing off as species of ances­tral rel­a­tives became extinct.

How the first Paran­thro­pus was found

In 1938, a school­boy, Gert Terblanche, dis­cov­ered a par­tial skull of a fos­sil hominid with unchar­ac­ter­is­tic fea­tures at Krom­draai, in the Cra­dle of Humankind. He hand­ed the prim­i­tive palate and a molar tooth to Sterkfontein’s quar­ry man­ag­er, George Bar­low, who reg­u­lar­ly gave Dr Robert Broom spec­i­mens to exam­ine. When the famous palaeon­tol­o­gist saw the fos­sil, he imme­di­ate­ly set out to find Terblanche.

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Paran­thro­pus robustus

I nat­u­ral­ly went to the school, and found the boy with four of what are per­haps the most valu­able teeth in the world in his trouser pock­et,” Broom lat­er said.

Terblanche led Broom to the Krom­draai site, where togeth­er they found part of the skull and jaw of the same spec­i­men. This dis­cov­ery led Broom to declare the fos­sils were evi­dence of a new hominid genus and species, Paran­thro­pus robus­tus.Paran­thro­pus had promi­nent cheek­bones, a mas­sive jaw and large teeth.

Lat­er dis­cov­er­ies of Paran­thro­pus at Swartkrans in the Cra­dle of Humankind and in East Africa showed the males had a bone ridge or sagit­tal crest” on the top of their heads to which pow­er­ful mus­cles were attached.

These heavy-chew­ing adap­ta­tions led Broom and his col­league, John Robin­son, to affirm that this hominid was in a sep­a­rate genus to Aus­tralo­p­ithe­cus, which many palaeoan­thro­pol­o­gists think is a more direct ances­tor of mod­ern humans.

Some palaeoan­thro­pol­o­gists still debate whether Paran­thro­pus is tru­ly anoth­er genus of hominid or just a robust species of Aus­tralo­p­ithe­cus, but the trend in recent years has been to agree with Broom and keep it in a sep­a­rate genus.

How the dif­fer­ent species weigh up

Aus­tralo­p­ithe­cus afaren­sis
Male: 1.51m (411”), 45kg (99lb)
Female: 1.95m (35”), 29kg (64lb)

Aus­tralo­p­ithe­cus africanus
Male: 1.38m (46”), 41kg (90lb)
Female: 1.15m (39”), 30kg (66lb)

Homo habilis
Male: 1.57m (52”), 52kg (115lb)
Female: 1.18m (310”), 32kg (71lb)

Paran­thro­pus robus­tus
Male: 1.32m (44”), 40kg (88lb)
Female: 1.1m (37”), 32kg (71lb)

Homo erec­tus
Male: 1.8m (511”), 66kg (146lb)
Female: 1.6m (53”), 56kg (123lb)

Homo hei­del­ber­gen­sis
Male: 1.82m (6’), 90kg (200lb)
Female: 1.54m (51”), 75kg (165lb)

Homo flo­re­sien­sis
Type spec­i­men is female: 1m (33”)

Homo sapi­ens (mod­ern)
Male: 1.75m (59”), 58kg (128lb)
Female: 1.61m (53”), 49kg (108lb)