Early pre-humans: Paranthropus fossil (Evolution)

by David Turell , Monday, March 31, 2025, 20:33 (2 days ago) @ David Turell

A new study on a leg fossil of a tiny hominid:

https://www.newscientist.com/article/2473905-unusually-tiny-hominin-deepens-mystery-of-...

'A fossilised left leg unearthed in South Africa belongs to one of the smallest adult hominins ever discovered – smaller even than the so-called “hobbit”, Homo floresiensis.

"The diminutive hominin was a member of the species Paranthropus robustus. This was one of several species of Paranthropus, a group of ape-like hominins that shared the African landscape with the earliest representatives of our human genus, Homo, between about 2.7 and 1.2 million years ago. Paranthropus had heavily built skulls that housed small brains and large teeth – which some species appear to have used to chew grass like a cow.

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"One thing that was instantly clear was that the fossil – a thighbone, shinbone and part of the hip – belonged to an unusually small hominin. “It’s impressive how small it is compared with the shortest of the short we’ve known about so far,” says Richard Potts at the Smithsonian Institution in Washington DC, who wasn’t involved in the analysis.

"Pickering’s team estimates that the hominin, which was probably a young adult female, stood just 103 centimetres tall. For comparison, the best-preserved H. floresiensis individual – who lived about 80,000 years ago – was 109 cm tall.

"Such a small hominin may well have been an easy target for predators, says Pickering, and so it might have sought shelter in trees. However, there are no clear indications in the leg bones that P. robustus had special adaptations for climbing. That is a surprise: a fragmentary skeleton of a related species – Paranthropus boisei – was discovered about a decade ago, and it did have climbing adaptations.

"The two species “may have engaged in different behaviours”, says Manuel Domínguez-Rodrigo at the University of Alcalá, Spain, who led the analysis of the P. boisei skeleton. This doesn’t necessarily mean that P. robustus couldn’t climb, says Pickering, although it is unclear why it lacked the climbing adaptations seen in P. boisei.

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"The fossil has, however, resolved at least one point of debate about P. robustus: exactly how it moved around on the ground. Although it is certain that the species could walk on two legs, it has long been unclear whether it did so most of the time or just occasionally. Thanks to the leg fossil, Pickering says we can now confirm P. robustus did walk on two legs most of the time. This, he says, is “the real revelation of our research”'.

Comment: it seems there my have been more than one line of descent to finally evolve sapiens. This is a very early hominid.