Category Archives: ETHIOPIA

Fossils that “clearly foreshadow” modern humans are 30,000 years older than we thought

Fossils that “clearly foreshadow” modern humans are 30,000 years older than we thought

The Omo I and Herto fossils, found in East Africa, are the oldest known Homo sapiens fossils yet discovered in the region — but a new study shows they are tens of thousands of years older than we thought. Older studies had dated the Omo I and Herto fossils to 197,000 years old and between 155,000 to 160,000 years old, respectively. They are, in fact, far older.

“The Omo I and Herto specimens are the oldest Homo Sapiens that have been found so far [in the region], so their discovery and their age are critical to understanding the emergence of our species,” Céline Vidal, lead author on the study and a volcanologist at Fitzwilliam College, tells Inverse.

Vidal and her team use ancient volcanic eruptions to date the human fossils. In a study published Wednesday in the journal Nature, they re-examine the Omo I and Herto fossils in Ethiopia. The findings push back the starting point for human history in eastern Africa by some 36,000 years.

Researchers analyzed pumice rock from an ancient volcanic eruption in the area to determine an updated age for the Omo I fossils.

HOW THEY DID IT — In the past, scientists had used the age of the volcanic ash layer beneath the old bones to infer when the fossils were deposited.

But, “there was some uncertainty on the position of this layer relative to the fossil,” Vidal says.

Unfortunately, the sediment layer above the fossils contains a kind of thick volcanic ash known as KHS; the grains of this kind of ash is too small to accurately date using the current technology — so this layer was no help in trying to narrow down the fossils’ true age. Instead, archaeologists have tried to determine the Omo I and Herto fossils’ ages using the signatures of other past volcanic eruptions in the area.

“While studying big eruptions from the Ethiopian Rift, we identified a colossal eruption of Shala volcano, which occurred some 233,000 years ago,” Vidal says. “The age was obtained from pumice rocks found near the volcano.”

In this study, Vidal’s team used a dating method known as “single crystal argon-argon” dating — in this method, the scientists measure the amount of the element argon in volcanic minerals like ash and pumice rock. This signature allows scientists to pinpoint when the magma originally erupted from the Earth’s surface.

Brian Stewart, an assistant professor of anthropology at the University of Michigan who was not involved in the study, tells Inverse that, generally, “single-crystal argon-argon dating is very well established and reliable,” and is “beautifully suited” to studying fossils in eastern Africa due to the history of volcanic eruptions in the area.

“It is a remarkable method because it can go as far back in time as the age of the Earth,” Vidal says. Or, in the case of Vidal’s work: As far back as the time of the oldest modern human beings.

WHAT THEY FOUND — The researchers obtained a more precise minimum age of the Omo I fossils, specifically that they are likely 233,000 years old. It’s worth keeping in mind that the margin of error is pretty significant: Plus or minus 22,000 years — so they may be even older or younger.

“The error margin associated with this new date is obviously very large, and at its upper — younger — margin does not massively change the previous age estimate of the Omo I finds, perhaps moving it back in time by 10-15,000 years,” Stewart says.

If their true age is closer to the median estimated date of 233,000 years — or even older — then the finding is “definitely significant” Stewart adds.

Either way, the Omo I fossil specimens — the oldest known Homo sapiens in eastern Africa — have officially become much, much older. Since some archaeologists believe early modern humans may have originated in this region, that makes the findings all the more significant.

“Our findings push the age of the oldest Homo sapiens to later than 200,000 years,” Vidal says.

Did humans originate in eastern Africa? The updated findings on the date of the Omo I fossils could shift how we think about the evolution of humans on the continent.

WHY IT MATTERS — For too long, the official archaeological date — the age of the oldest known fossils of Homo sapiens from eastern Africa — hasn’t matched up with evolutionary models of human history. Evolutionary models suggest our species arose some 300,000 years ago. The oldest ever Homo sapiens fossils were discovered in Morocco — it is some 300,000 years old.

“The Omo I fossils exhibit traits that much more clearly foreshadow later Homo sapiens than those displayed by what has been proposed as the very earliest specimens in the sapiens lineage: the 300,000-year-old fossil skulls from Jebel Irhoud in Morocco,” Stewart says. The discovery puts the archaeological date of the Omo I fossils in closer proximity to this evolutionary timeline for Homo sapiens.

“This new age constraint is congruent with most models for the evolution of modern humans, which estimate the origin of H. sapiens and its divergence from archaic humans at about 350–200 thousand years ago,” Vidal says.

The findings could help settle another longstanding archaeological debate: Did our species originate in a single area in eastern Africa, or from multiple areas of the continent?

“Current opinions of our species’ origins have shifted away from a single-region African model and towards a multiregional African model,” Stewart says. The updated timeline of the Omo I fossils could shift the thinking about where and how humans evolved in Africa once more, Stewart explains:

“If the more modern-looking Omo specimens turn out to fall squarely within that time envelope, we may need think twice before we toss out a single origin model altogether, especially one that sees our species evolving across a single interconnected region that was much larger than previously imagined.”

WHAT’S NEXT — For now, Vidal and her team are clear: This is far from a definitive conclusion on the origins of humanity. While the study provides an updated “minimum age” for these fossil specimens in eastern Africa, the “maximum age” — i.e., the oldest age of the Omo I humans — is still a mystery.

Also, further research is needed to provide a more accurate age for the Herto fossils — the other significant site of ancient Homo sapiens found in the region.

“We can only date humanity based on the fossils that we have, so it’s impossible to say that this is the definitive age of our species,” Vidal says.

Future fossil findings could very well push the timeline of modern Homo sapiens “even further back in time.”

“The study of human evolution is always in motion; boundaries and timelines change as our understanding improves,” Vidal says.

Abstract: Efforts to date the oldest modern human fossils in eastern Africa, from Omo-Kibish1–3 and Herto4,5 in Ethiopia, have drawn on a variety of chronometric evidence, including 40Ar/39Ar ages of stratigraphically associated tuffs. The ages that are generally reported for these fossils are around 197 thousand years (kyr) for the Kibish Omo I3,6,7, and around 160–155 kyr for the Herto hominins5,8. However, the stratigraphic relationships and tephra correlations that underpin these estimates have been challenged6,8. Here we report geochemical analyses that link the Kamoya’s Hominid Site (KHS) Tuff9, which conclusively overlies the member of the Kibish Formation that contains Omo I, with a major explosive eruption of Shala volcano in the Main Ethiopian Rift. By dating the proximal deposits of this eruption, we obtain a new minimum age for the Omo fossils of 233 ± 22 kyr. Contrary to previous arguments6,8, we also show that the KHS Tuff does not correlate with another widespread tephra layer, the Waidedo Vitric Tuff, and therefore cannot anchor a minimum age for the Herto fossils. Shifting the age of the oldest known Homo sapiens fossils in eastern Africa to before around 200 thousand years ago is consistent with independent evidence for greater antiquity of the modern human lineage.

Ancient city found in Ethiopia sheds new light on the country’s history

Ancient city found in Ethiopia sheds new light on country’s history

Archaeologists have uncovered an ancient, forgotten city in Ethiopia once thought to be the home of giants. The discovery reveals important new information about the origins of international trade and Islam in the country between the 10th and early 15th centuries.

This is the first evidence that proves Eastern Ethiopia was well connected with the Gulf, Egypt and India hundreds of years ago and highlights how skilled craftsmen traded with communities around the world and lived alongside people from different areas around the Indian Ocean and the Red Sea.

A dig in Harlaa, Eastern Ethiopia, has revealed a 12th-century mosque, evidence of Islamic burials and headstones as well as glass vessel fragments, rock crystal, carnelian, glass beads, imported cowry shells, and pottery from Madagascar, the Maldives, Yemen and China. Archaeologists have found bronze and silver coins from 13th-century Egypt.

A dig in Harlaa, Eastern Ethiopia, has revealed a 12th-century mosque.

There has so far been very little archaeological research carried out in Islamic sites in Ethiopia, with experts more focused on finding early humans in the region.

Archaeologists had not previously carried out extensive work in this part of Ethiopia. Farmers had been uncovering pottery and coins for many years in the area and were convinced there was rich information about Ethiopia’s history to be found underground.

The size of some of the building stones also found created a local legend that the area had been home to giants.

Archaeologists worked with the community for two years to make the discoveries, which will be exhibited in a heritage centre run by local people designed to bring income to the area.

Some findings will be displayed in the country’s national museum in Addis Ababa. The work was completed in partnership with the Ethiopian Authority for Research and Conservation of Cultural Heritage.

Professor Timothy Insoll, from the Institute of Arabic and Islamic Studies at the University of Exeter, who led the research, said: “This discovery revolutionises our understanding of trade in an archaeologically neglected part of Ethiopia. What we have found shows this area was the centre of trade in that region.

The city was a rich, cosmopolitan centre for jewellery making and pieces were then taken to be sold around the region and beyond. Residents of Harlaa were a mixed community of foreigners and local people who traded with others in the Red Sea, Indian Ocean and possibly as far away as the Arabian Gulf.”

Harlaa is 120km from the Red Sea coast and 300km from Addis Adaba. The architecture of the mosque is similar to those found in Southern Tanzania and Somaliland, showing connections between different Islamic communities in Africa.

Remains found in the dig suggest jewellers were making high-quality, delicate pieces in silver, bronze and semi-precious stones and glass beads. They used some technology usually associated in that period with jewellers in India, suggesting trade or immigration from that country to Harlaa.

The settlement, which is around 500m by 1,000m, has buildings and walls constructed with large stone blocks – leading people to assume only those with enormous stature or strength could have built it, and encouraging local legends about giants having inhabited the region.

The remains of some of the 300 people buried in the cemetery are being analysed to see what their diet consisted of.

Professor Insoll said: “The archaeological findings suggest this place was home to a very mixed community. Local people were extremely keen for us to solve mysteries. Farmers had been finding strange objects, including Chinese coins, as they were working on their land, and a legend began that the area was home to giants. We have obviously disproved that, but I’m not sure they fully believe us yet. Some people have said the bodies we have discovered are the children of giants!”

The research is funded by the European Research Council and previously by the Max Van Berchem Foundation in Switzerland.

The archaeologists, from the Universities of Exeter, Addis Ababa and Leuven, will dig again next year, in other sites and deeper underground, to uncover more evidence of people who lived there earlier in history. So far, they have excavated down to a depth of 2.5 metres and dated this to the 6th century.

Professor Insoll said: “We know jewellery was being made here for trading into the African interior, and materials to do this came in from the Red Sea, East African Coast and possibly India, but we don’t know what was given in exchange for that jewellery. During the next stage of our archaeological research in this era, we hope to examine this by working on other sites up to 100km away.”

The earliest human remains in eastern Africa dated to more than 230,000 years ago

Earliest human remains in eastern Africa dated to more than 230,000 years ago

Ancient human fossils discovered in Ethiopia are much older than previously thought, experts claim, saying they could be as much as 230,000 years old. The remains – known as Omo I – were discovered in Ethiopia in the late 1960s, and are one of the oldest known examples of Homo sapiens fossils, with earlier attempts to date them placing them at just under 200,000 years old. However, a new study by the University of Cambridge found that the remains have to pre-date a colossal volcanic eruption in the area, which happened 230,000 years ago. 

To make the discovery the team dated the chemical fingerprints of volcanic ash layers, found above and below sediment where the fossils were discovered. 

The team said that while this pushes the minimum age for Homo sapiens in eastern Africa back by 30,000 years, future studies may extend the age even further. In 2017, archaeologists announced the discovery of the world’s oldest Homo sapiens fossils — a 300,000-year-old skull at Jebel Irhoud in Morocco. 

The Omo Kibish Formation in south western Ethiopia, within the East African Rift valley. The oldest human remains in east Africa date back at least 30,000 years earlier than previously thought to around a quarter of a million years ago
The remains – known as Omo I – were discovered in Ethiopia in the late 1960s, and are one of the oldest known examples of Homo sapiens fossils, with earlier attempts to date them placing them at less than 200,000 years old

To date, the volcanic remains, the team collected pumice rock samples from the volcanic deposits and ground them down to sub-millimetre size. Scientists have been trying to precisely date the oldest fossils in eastern Africa, widely recognised as representing our species, Homo sapiens, ever since they were discovered in the 1960s. Earlier attempts to date them suggested they were less than 200,000 years old.  The Omo I remains were found in the Omo Kibish Formation in southwestern Ethiopia, which sits within the East African Rift valley.  The region is an area of high volcanic activity and a rich source of early human remains and artefacts.

By dating layers of volcanic ash above and below where fossil materials are found, scientists identified Omo I as one of the earliest examples of our species ever found.

‘Using these methods, the generally accepted age of the Omo fossils is under 200,000 years, but there’s been a lot of uncertainty around this date,’ said Dr Céline Vidal from Cambridge’s Department of Geography, the paper’s lead author. 

‘The fossils were found in a sequence, below a thick layer of volcanic ash that nobody had managed to date because the ash is too fine-grained.’

The four-year project, led by British volcanologist Professor Clive Oppenheimer. is attempting to date all major volcanic eruptions in the Ethiopian Rift. Each eruption has its own fingerprint – its own evolutionary story below the surface, which is determined by the pathway the magma followed,’ said Dr Vidal. 

‘Once you’ve crushed the rock, you free the minerals within, and then you can date them, and identify the chemical signature of the volcanic glass that holds the minerals together.’

The researchers carried out a geochemical analysis on the crushed rock to link the fingerprint of the volcanic ash, from the Kamoya Hominin Site, with an eruption of Shala volcano.  The team then dated pumice samples from the volcano, 250 miles from the site the human remains were discovered, to 230,000 years ago.  Since the Omo I fossils was found deeper than this particular ash layer, they must be more than 230,000 years old, the team explained.

‘First I found there was a geochemical match, but we didn’t have the age of the Shala eruption,’ said Vidal.

‘I immediately sent the samples of Shala volcano to our colleagues in Glasgow so they could measure the age of the rocks. 

When I received the results and found out that the oldest Homo sapiens from the region was older than previously assumed, I was really excited. Professor Asfawossen Asrat, a co-author of the study from Addis Ababa University in Ethiopia, said: ‘The Omo Kibish Formation is an extensive sedimentary deposit which has been barely accessed and investigated in the past. Our closer look into the stratigraphy of the Omo Kibish Formation, particularly the ash layers, allowed us to push the age of the oldest Homo sapiens in the region to at least 230,000 years.

The team said that while this pushes the minimum age for Homo sapiens in eastern Africa back by 30,000 years, future studies may extend the age even further
To date the volcanic remains, the team collected pumice rock samples from the volcanic deposits and ground them down to sub-millimetre size
Scientists have been trying to precisely date the oldest fossils in eastern Africa widely recognised as representing our species, Homo sapiens, ever since they were discovered in the 1960s

Unlike other Middle Pleistocene fossils which are thought to belong to the early stages of the Homo sapiens lineage, Omo I possesses unequivocal modern human characteristics, according to co-author Dr Aurélien Mounier, from the Musée de l’Homme in Paris.

He gave the example of a ‘tall and globular cranial vault and a chin’, before claiming that the new date estimate made the remains ‘the oldest unchallenged Homo sapiens in Africa. Until the Jebel Irhous discovery four years ago, most researchers believed that all humans living today descended from a population that lived in East Africa around 200,000 years ago. 

‘We can only date humanity based on the fossils that we have, so it’s impossible to say that this is the definitive age of our species,’ said Vidal.  The study of human evolution is always in motion: boundaries and timelines change as our understanding improves.  But these fossils show just how resilient humans are: that we survived, thrived and migrated in an area that was so prone to natural disasters. It’s probably no coincidence that our earliest ancestors lived in such a geologically active rift valley – it collected rainfall in lakes, providing fresh water and attracting animals, and served as a natural migration corridor stretching thousands of kilometres,’ said Oppenheimer. 

The volcanoes provided fantastic materials to make stone tools and from time to time we had to develop our cognitive skills when large eruptions transformed the landscape. Our forensic approach provides a new minimum age for Homo sapiens in eastern Africa, but the challenge still remains to provide a cap, a maximum age, for their emergence, which is widely believed to have taken place in this region,’ said co-author Professor Christine Lane, head of the Cambridge Tephra Laboratory. 

The Omo I remains were found in the Omo Kibish Formation in southwestern Ethiopia, which sits within the East African Rift valley

It’s possible that new finds and new studies may extend the age of our species even further back in time. There are many other ash layers we are trying to correlate with eruptions of the Ethiopian Rift and ash deposits from other sedimentary formations,’ said Vidal. ‘In time, we hope to better constrain the age of other fossils in the region.’

The findings have been published in the journal Nature.

What is the oldest-known archaeological site in the world?

What is the oldest-known archaeological site in the world?

Our human ancestors were roaming Earth as far back as 6 million years ago, but what is the earliest site containing archaeological evidence of their existence? 

It turns out, there are two spots — one in Kenya and the other in Ethiopia — that are considered the top candidates for the world’s oldest archaeological sites, according to about a dozen scholars, all with expertise in prehistoric archaeology and anthropology, who spoke with Live Science. 

The question of what is the oldest archaeological site in the world is “a topic that has since recently divided the archaeological community,” Yonatan Sahle, a senior lecturer of archaeology at the University of Cape Town in South Africa, told Live Science in an email. 

The first site, called Lomekwi 3, holds bones of hominins as well as stone artefacts and is located on a low hill in West Turkana, Kenya. In a study published in 2015 in the journal Nature, researchers reported that, by dating the sediment where the artefacts were found, they estimated the age of the site to be about 3.3 million years.

The finds “mark a new beginning to the known archaeological record,” a team of scientists wrote in the journal article. The tools were likely created by Australopithecus afarensis, a hominin (human ancestors and their relatives) that thrived in the region at the time. 

The site is located in a wooded area on a small hill not far from Lake Turkana. It’s possible that Australopithecus afarensis was using the stone artefacts to break open nuts the team wrote in the paper. The number of people who lived at the site at any given time is not clear. 

“Lomekwi 3 is the oldest known archaeological site in the world,” Jason Lewis, assistant director of the Turkana Basin Institute and a co-author of the paper, told Live Science in an email. 

Jeremy DeSilva, an associate professor of anthropology at Dartmouth College who was not involved in the study, agreed that Lomekwi 3 is the oldest known archaeological site, but he noted that not all scholars agree. “Lomekwi is controversial, and some of our colleagues remain unconvinced of the antiquity of these tools,” DeSilva told Live Science. 

Indeed, a number of recent papers “call into question the status of the artefacts at Lomekwi 3, arguing that some of the artefacts were not actually found in a context where the age of the artefacts can be certain,” David Braun, an anthropology professor at The George Washington University, told Live Science. In other words, the artefacts may not date to the same time as the sediment that it was found in.

Sahle is one of those archaeologists. “For many of us — myself included — unequivocal evidence for the oldest archaeological occurrences comes in the form of 2.6-million-year-old stone tools from Gona,” which is located by the Kada Gona river in Afar, Ethiopia, Sahle said. The dating results for Lomekwi 3 are contested, he noted, and he has serious doubts that the remains found at that site date back 3.3 million years. 

The research at Lomekwi 3 was published relatively recently, whereas research at Gona has been published over several decades and has withstood academic scrutiny, Sahle said. “Inferences made on the chronological and behavioural context of [the] Gona archaeological assemblages derive from decades of research and have, therefore, withstood the test of time,” Sahle said. 

A stone tool was unearthed at the Lomekwi 3 excavation site next to Lake Turkana in Kenya.

The stone tools at Gona may have been made by Australopithecus Garhi, a human ancestor that lived in east Africa around 2.5 million years ago. Fossils of the species have been found near stone tools and they may have been one of the first human ancestors to make sophisticated stone tools Smithsonian’s Human Origins project website notes.

“The Lomekwi claims were not adequately demonstrated when announced, and there has [been] no new evidence provided, despite several well-considered criticisms of the original Nature announcement,” said Tim White, co-director of the Human Evolution Research Center at the University of California, Berkeley. White agrees that Gona has the best unequivocal evidence for being the oldest archaeological site.

On the other hand, some scholars are supportive of the idea that Lomekwi is older than Gona. Rick Potts, director of the Smithsonian’s Human Origins Program, is convinced that Lomekwi 3 “is the oldest site with solid evidence of stone-on-stone percussion,” meaning that it’s the oldest site that has stone artefacts made by human ancestors. He noted that the stone artefacts at Lomekwi 3 appear different from those found at Gona; they are cruder and may not have been used as tools at all. The stone artefacts at Lomekwi 3 “show awkward fracturing of the rocks, including large, thick, irregularly shaped flakes that could have been the accidental byproducts of pounding — for what purpose, no one currently knows,” Potts wrote in an email, noting that people at Lomekwi 3 may not have been creating tools but rather pounding rocks together for unknown reasons. Even if the Lomekwi 3 artefacts weren’t used as tools, they would still be considered artefacts created by humans. 

Brian Villmoare, an associate professor of anthropology at the University of Nevada, told Live Science, “I do tend to think that Australopithecus afarensis could have made stone tools,” but he noted that he has not examined the Lomekwi 3 artefacts. 

A third candidate?

Braun said that if future fieldwork cannot alleviate concerns about the dating of Lomekwi 3, his second choice for the oldest archaeological site would be Ledi-Geraru in Afar, Ethiopia, which dates back about 2.8 million years.

The earliest-known fossil from the Homo genus, this piece of the jawbone, was discovered at a site called Ledi-Geraru in the Afar Regional State, Ethiopia.

At Ledi-Geraru, researchers found a partial hominin mandible with teeth, and they dated it by examining the age of the surrounding sediment, they reported in the journal Science in 2015.  Sahle expressed doubts about the dating of this site, saying that it may be considerably younger than 2.8 million years and that Gona is the site with the best unequivocal evidence. 

Regardless of which of these archaeological sites is the oldest, all of them make the Giza pyramids (which are about 4,500 years old) and Stonehenge (which is roughly 5,000 years old) relatively young by comparison. 

The Atlantic Ocean was known as the Ethiopian Ocean until the 19th century

The Atlantic Ocean was known as the Ethiopian Ocean until the 19th century

Up to the 19th century, the southern part of the Atlantic Ocean was formally known as the Ethiopian/Aethiopian Sea in classical geographical works. This was the name that appeared on ancient maps, up to the 19th century.

1747 map showing the oceans and seas surrounding the African continent

The roots of such etymology can be described by how over time, areas referred to as place names often expand or contract. As such, what is termed “toponymic displacement” or geographic displacement? becomes commonplace.

European geographers used the term ‘Libyan’ to refer to North African people of Berber background. The people who inhabited lands further south of the Sahara were called ‘Ethiopians’ (or Aethiopians) and the name used for the lands below the Sahara was ‘Ethiopia.’

Ethiopia was also used as the synonym for the Nubian Kingdom of Kush (or Meroe).

The present country called Ethiopia was hardly known, and when it came to the knowledge of European geographers it was called ‘Abyssinia’ (from the Arabic ethnic designation ‘Habesh.’

The word Ethiopia was also used for unknown or quasi-mythical lands situated to the south or east of the Mediterranean.

1710 map of Africa by Daniel de la Feuille

The African interior, which was unknown to European ‘explorers’ and geographers around the 15th-16th centuries, was generally called Ethiopia.

The eastern South Atlantic Ocean was called the Aethiopian/Ethiopian Sea/Ocean due to the fact such part of the ocean was in proximity to the landmass called Ethiopia. This part of the ocean was commonly dubbed the “Ethiopian Ocean” (or Sea) through the 1700s.

In the maps of this time, the Ethiopian Ocean was shown to stretch from the South Atlantic into the western Indian Ocean.

Oceans and seas were conceptualized and titled as strips of water surrounding landmasses.

The discreet naming of oceans surfaced in the 1800s.

See Also: MORE ARCHAEOLOGY NEWS

Decades after the classical use of the name had become obsolete, botanist William Albert Setchell (1864–1943) used the term for the sea around some islands near Antarctica.

This 3.3-Million-Year-Old Hominin Toddler Was Kind of Like Us

This 3.3-Million-Year-Old Hominin Toddler Was Kind of Like Us

In a fragment of sandstone sticking from the soil in the sparkling flatlands of Northeast Ethiopia, a fossil fragment of the cheekbone has been detected. Zeresenay Alemseged almost instinctively realised that he had come across something important.

This 3.3-Million-Year-Old Hominin Toddler Was Kind of Like Us
Zeresenay Alemseged holds the skull of a three-year-old Australopithecus afarensis at the National Museum of Ethiopia in Addis Ababa, Ethiopia. The discovery sheds light on the contentious debate about how well the species walked and climbed.

The skinbone brought a jaw, parts of a skull and eventually collar bones, shoulder blades, ribs and — perhaps most important — the most complete spinal column of any early human relative ever found.

Nearly 17 years later, the 3.3-million-year-old fossilized skeleton known as the “Dikika Baby” remains one of the most important discoveries in archaeological history, one that is filling in the timeline of human evolution.

“When you put all the bones together, you have over 60 per cent of a skeleton of a child dating back to 3.3 million years ago, which is more complete than the famous australopithecine fossil known as ‘Lucy,’ ” Alemseged, a 47-year-old professor of organismal biology and anatomy at the University of Chicago, told The Washington Post.

“We never had the chance to recover the face of Lucy, but the Dikika child is an almost complete skeleton, which gives you an impression of how children looked 3.3 million years ago.”

The fossil, also called  “Selam” — “peace” in the Ethiopian Amharic language — has revealed numerous insights into our early human relatives. But Alemseged said one of the most startling findings comes from the toddler’s spine, which had an adaptation for walking upright that had not been seen in such an old skeleton.

The result, he said, is a creature whose upper body was apelike, but whose pelvis, legs and feet had familiar, humanlike adaptations.

“If you had a time machine and saw a group of these early human relatives, what you would have said right away is, ‘What is that chimpanzee doing walking on two legs?’ ” Alemseged said.

The Dikika foot is one part of a partial skeleton of a 3.32 million-year-old skeleton of an Australopithecus afarensis child

The findings, published in the Proceedings of the National Academy of Sciences, show for the first time the spinal column was humanlike in its numbering and segmentation. Though scientists know that even older species were bipedal, researchers said Selam’s fossilized vertebrae is the only hard evidence of bipedal adaptations in an ancient hominid spine.

“Yes, there were other bipedal species before, but what is making this unique is the preservation of the spine, which simply is unprecedented,” Alemseged said. “Not only is it exquisitely preserved, but it also tells us that the human-type of segmentation emerged at least 3.3 million years ago. Could there have been other species with a similar structure, yes, but we don’t know for sure?”

Human beings share many of the same spinal structures as other primates, but the human spine — which has more vertebrae in the lower back, for example — is adapted for efficient upright motion, such as walking and running on two feet.

Among the larger questions researchers like Alemseged are trying to answer include: When did our ancestors evolve the ability to be bipedal? When did we become more bipedal than arboreal, or tree-dwelling? And when did our ancestors abandon an arboreal lifestyle to become the runners and walkers that eventually populated Africa and then the world?

One of the significant barriers to answering those questions is that complete sets of vertebrae are rarely preserved in the fossil record.

“For many years we have known of fragmentary remains of early fossil species that suggest that the shift from rib-bearing, or thoracic, vertebrae to the lumbar, or lower back, vertebrae were positioned higher in the spinal column than in living humans, but we have not been able to determine how many vertebrae our early ancestors had,” said Carol Ward, a curator’s distinguished professor of pathology and anatomical sciences in the University of Missouri School of Medicine, and lead author on the study.

Selam has provided us the first glimpse into how our early ancestors’ spines were organized.” Unpacking the intricacies of Selam’s spinal structure would not have been possible without the assistance of cutting-edge technology, researchers said.

After 13 years of using dental tools to painstakingly remove portions of the fossil from sandstone — which risked destroying the fossil — Alemseged packed up Selam in his suitcase and took the fossil from Ethiopia to the European Synchrotron Radiation Facility in Grenoble, France, in 2010. Alemseged and the research team spent nearly two weeks there using high-resolution imaging technology to visualize the bones.

Left block of images shows the 3.32 million-year-old foot from an Australopithecus afarensis toddler from different angles. The right block of images compares the child’s foot with the fossil remains of an adult Australopithecus foot (top).

The fossil had undergone a medical CT scan in 2002 in Nairobi, Alemseged said, but that scanner was unable to distinguish objects with the same density, meaning that penetrating bones encased in sandstone was impossible. Once in France, that was no longer a problem, and the results, he said, “were mind-blowing.”

“We were able to separate, virtually, the different elements of the vertebrae and were able to do it, of course, without any damage to the fossil,” Alemseged said. “We are now able to see this very detailed anatomy of the vertebrae of this exceptionally preserved fossil.”

The scans revealed that the child possessed the thoracic-to-lumbar joint transition found in other fossil human relatives, but they also showed that Selam had a smaller number of vertebrae and ribs than most apes have.

For researchers, the skeleton is a window into the transition between rib-bearing vertebrae and lower back vertebrae, which allowed our early human ancestors to extend at the waist and begin moving upright, eventually becoming highly efficient walkers and runners. Though he has been studying Selam for nearly two decades, Alemseged thinks the fossil has more secrets to share with the modern world.

“I don’t think she will stop surprising us as the analysis continues,” he said. “Science and tech are evolving so much that I’m sure in a few years we’ll be able to extract even more information that we’re not able to extract today.”