New analysis has shown that an ancient relative of humankind lived in South Africa 2 million years ago and walked as a human, but could climb like an ape.
Scientists said the discovery of new lower back fossils belonging to Australopithecus sediba had settled a decades old debate about how early hominins moved.
A curved spine was found in the’missing connection’, which suggests that this species spent most of their time on its two feet, and also used their upper limbs for climbing like apes.
New York University’s University of the Witwatersrand and Johannesburg’s University of the Witwatersrand led an international research team that used bone fragments from South African caverns to construct one of the best-preserved back fossils of any hominin.
Lee Berger of the University of the Witwatersrand was the first to describe Australopithecus sediba.
New analysis has shown that Australopithecus Sediba, an ancient human relative, was able to walk like a person but climb like an ape.
Scientists believe that Australopithecus sediba’s discovery of fossils at the lower back (pictured) has resolved decades old controversy about whether early hominins evolved.
Professor Berger and his then nine-year-old son Matthew had found the first remains of the extinct species in the Malapa cave, which were later identified as a male child called Karabo and an adult female.
These fossils were found during 2015 excavations of a trackway for mining that ran near Malapa, in the Cradle of Humankind World Heritage Site north-west of Johannesburg.
The four vertebrae are located at the female’s lower back, and the sacrum is a bone connecting the spine and pelvis. Swahili for ‘protector’, the team named the female Issa.
It was also discovered that sediba only had five lumbar vertebrae, just like human beings.
Professor Scott Williams of New York University, the lead author, said that the lumbar region was crucial to understand bipedalism and how early ancestors were able to walk on two feet.
The ‘Associated Series of Lumbar Vertebrae is Extremely Rare in the Hominin Fossil Record, With Only Three Similar Lower Spines from the Early African Record.
A curved spine was found in the’missing connection’, which suggests that this species spent most of their time on its two feet, and also used their upper limbs for climbing like apes.
Lee Berger (pictured) and his University of the Witwatersrand team first identified Australopithecus Sediba.
With the discovery of these new specimens, Issa is now one of two hominin skeletons that has both the lower spine and the dentition of an early hominin. This allows for certainty about the species of spine.
Berger who was an author of the new study said that Issa had been a complete skeleton of an ancient hominin, and these vertebrae complete it.
The combination of preservation and completeness gave him the opportunity to show the scientists the unique anatomy at the lower back.
The authors of previous studies on the lower spine that were not part in this study suggested that sediba had a straight spine without any curvature or lordosis as seen in modern people.
The researchers further speculated that Issa’s spine was similar to the extinct Neanderthals species, and other primitive species of ancient Hominins older then two million years.
Lordosis, the inward curve on the lumbar spine is called and used to display strong adaptations to bipedalism.
Nevertheless, the study showed that the lordosis found in sediba’s spine is much more extensive than the other australopithecines. It also revealed that the curvature seen in the spines of some humans and the Turkana boy, Homo erectus, a 1.6-million year-old Turkana boy, was even more dramatic.
Professor Gabrielle Russo of Stony Brook University said that while the appearance of lordosis, and other spine features clearly indicate adaptations for walking on two feet, other features such as large, upward-oriented transverse processes suggest strong trunk muscles, possibly for arboreal behavior.
It was also discovered that sediba, like humans had just five lumbar vertebrae.
As seen in apes, strong upward-oriented transverse spines indicate powerful trunk muscles.
Professor Shahed Nalla of the University of Johannesburg said that when combined with other anatomy parts, it indicates that sediba has clear adaptations for climbing.
Studies of the ancient species revealed mixed adaptations in the skeleton. These adaptations have been shown to indicate its ability to walk like humans and climb.
This includes features in the pelvis, upper and lower limbs.
‘The spine ties this all together,’ said Professor Cody Prang of Texas A&M, who studies how ancient hominins walked and climbed.
“In what way these traits persist in our ancestral ancestors is one of the most important questions about human origins. This includes potential adaptations to walking on the ground with two feet and climbing trees.
According to the study, sediba was a transitional human relative. Its spine clearly differs from modern humans and Neanderthals.
Berger stated that while Issa looked a lot like a person, she was capable of climbing like an ape.
The new research is published in the journal eLife.
Neanderthals were a distant relative of the modern human race, but they went extinct around 40,000 years ago
Neanderthals, a human close ancestor mysteriously disappeared around 40,000 years back.
They lived for thousands of years in Africa, with the early human ancestors. Then they moved across Europe to live around 300,000 year ago.
Later, they were joined by human beings who arrived in Eurasia 48,000 years after their arrival.
The Neanderthals were a cousin species of humans but not a direct ancestor – the two species split from a common ancestor – that perished around 50,000 years ago. A Neanderthal museum exhibit is shown here
These cavemen were originally thought to be dumb and primitive compared with modern human beings.
It has been increasingly obvious, especially in the last 10 years, that we are selling Neanderthals undervalued.
An increasing number of evidence supports the idea that a caveman is more advanced and versatile than previously thought.
The possibility exists that Neanderthals may have told their stories, buried and painted the bodies of their loved ones, as well as interbreeding with human beings.
They created body art using pigments, beads and other materials. The earliest human art was probably predated by the Neanderthal Cave Art (and symbolism in Spain) of around 20,000 years.
It is believed that they hunted and did some fishing on the land. After the triumph of Homo Sapiens in Europe, however, they became extinct around 40,000 Years ago.