logo
We've Just Learned More About the Mysterious People of the Green Sahara

We've Just Learned More About the Mysterious People of the Green Sahara

Yahoo11-04-2025

Lush greenery is as unexpected in the Sahara as it is in Antarctica. Yet both were once home to more temperate ecosystems. Unlike the jungles of Antarctica, which froze away many millions of years ago, the Green Sahara was recent enough to host early humans.
Every 21,000 years, the Sahara experiences a wet, rainy period, turning it into a woodland. The last North African Humid Period occurred between 14,500 and 5,000 years ago. During that time, an enigmatic group of pastoral people called the region home.
But who exactly were they? Where did they come from? What happened to them when their home became a desert again? All this has long been a matter of debate.
A new study in Nature reveals the results of DNA testing, suggesting a clearer origin for the Green Sahara people.
The Takarkori rock shelter is tucked against the Tadrart Acacus Mountains of southwest Libya. Humans lived here from 10,200 to 4,200 years ago. Archaeologists have unearthed a number of artifacts, the most important finds are the 15 sets of human remains in the back of the cave.
A team from the Max Planck Institute for Evolutionary Anthropology in Germany decided the most likely remains for testing were a pair of adult female mummies carbon-dated from 6,800 to 6,300 years ago. Carefully, researchers extracted genetic material from their naturally mummified remains.
Conditions in the Sahara degrade DNA, making research into population change extremely difficult. The DNA was too damaged to construct a complete genome, but researchers were able to compare specific sections of code to almost 800 individuals from modern Africa, the Near East, and Southern Europe.
Genetic analysis revealed that the Takarkori people were part of a unique, somewhat isolated group. Their overall ancestry was North African, and significant migration in or out of their population had not occurred.
This runs counter to previous theories, which suggested northward migration from sub-Saharan Africa. Around the height of the last humid period, the Green Sahara people moved from hunter-gathering to a more sedentary herder's life. Previously, researchers believed that sub-Saharan people moving through the area had introduced domestication.
The Takarkori people. also had far less Neanderthal DNA than other North African populations. They were fairly isolated genetically, but with a moderate population of around 1,000 people, they weren't in a population bottleneck.

Orange background

Try Our AI Features

Explore what Daily8 AI can do for you:

Comments

No comments yet...

Related Articles

Fossils found in 1970s are most recent ancestor of tyrannosaurs, scientists say
Fossils found in 1970s are most recent ancestor of tyrannosaurs, scientists say

Yahoo

time4 hours ago

  • Yahoo

Fossils found in 1970s are most recent ancestor of tyrannosaurs, scientists say

Tyrannosaurs might evoke images of serrated teeth, massive bodies and powerful tails, but their most recent ancestor yet discovered was a slender, fleet-footed beast of rather more modest size. Experts say the new species – identified from two partial skeletons – helps fill a gap in the fossil record between the small, early ancestors of tyrannosaurs and the huge predators that evolved later. Related: Birds were nesting in the Arctic during age of dinosaurs, scientists discover 'They're almost the immediate ancestor of the family called that we call tyrannosaurs,' said Dr Darla Zelenitsky, co-author of the study at the University of Calgary. Writing in the journal Nature, Zelenitsky and colleagues report how they re-examined fossils unearthed in Mongolia in the early 1970s, and now held at the Institute of Paleontology of the Mongolian Academy of Sciences. The team discovered the 86m-year-old skeletons did not belong to the tyrannosaur ancestor they had previously been identified with, an enigmatic creature called Alectrosaurus olseni. Instead, they belonged to a new species the researchers have called Khankhuuluu mongoliensis, meaning 'Prince of Dragons of Mongolia'. Jared Voris, first author of the research, said the fossils showed signs of some typical tyrannosaur features. However, others were absent. While later predators, such as T rex, could reach colossal sizes, weighing up to 8,000kg, Khankhuuluu was more modest, at about 4 metres in length and weighing about 750kg. Voris said that while humans would have been a mere snack to a T rex, they would have been the perfect prey for Khankhuuluu had they lived at the same time. 'You would have been the thing that it would hunt down, and it would have been faster than you,' he said. 'I would much rather run into an adult T rex than run into Khankhuuluu.' The discovery also sheds light on a group of small, long-nosed tyrannosaurs called Alioramus – often called 'Pinocchio rexes' – that some had proposed might sit closer to the ancestors of tyrannosaurs on the family tree than to T rex and its ilk. However, the new work shows this is not the case. 'We found that their closest relatives are the giant forms like T rex and Tarbosaurus,' said Zelenitsky. The team say that suggests Alioramus was something of a quirk, evolving an exaggerated juvenile tyrannosaur form within a part of the family tree dominated by behemoths. The researchers then used a computer model that incorporated the new tyrannosaur family tree, together with the age and locations of known species, to explore when and where missing relatives would have emerged. This enabled them to unpick the waves of migration made by tyrannosaurs and their ancestors over land bridges between Asia and North America. Zelenitsky noted such movements were found to be less sporadic and frequent than previously thought. The results revealed Khankhuuluu, or closely related species in Asia, migrated to North America where tyrannosaurs subsequently evolved. Some tyrannosaurs later moved back into Asia, where the large Tarbosaurus and smaller Pinocchio rexes emerged. Finally, some huge species of tyrannosaur migrated back to North America, giving rise to T rex and other enormous predators. Prof Steve Brusatte of the University of Edinburgh, who was not involved in the work, said the age of Khankhuuluu was important, given there are so few fossils from that time. Brusatte added the relatively small size of Khankhuuluu showed it was only later that tyrannosaurs became colossal, while the study also reveals a few big migration events back and forth between Asia and North America were the drivers of much of tyrannosaur evolution. 'The tyrannosaur family tree was shaped by migration, just like so many of our human families,' he said.

A ‘dragon prince' dinosaur is redrawing the tyrannosaur family tree
A ‘dragon prince' dinosaur is redrawing the tyrannosaur family tree

Yahoo

time4 hours ago

  • Yahoo

A ‘dragon prince' dinosaur is redrawing the tyrannosaur family tree

Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Scientists have identified a previously unknown 86 million-year-old dinosaur species that fills an early gap in the fossil record of tyrannosaurs, revealing how they evolved to become massive apex predators. Researchers analyzing the species' remains have named it Khankhuuluu mongoliensis, which translates to 'dragon prince of Mongolia,' because it was small compared with its much larger relatives such as Tyrannosaurus rex, whose name means 'the tyrant lizard king.' The newly identified dinosaur was the closest known ancestor of tyrannosaurs and likely served as a transitional species from earlier tyrannosauroid species, according to the findings published Wednesday in the journal Nature. Based on a reexamination of two partial skeletons uncovered in Mongolia's Gobi Desert in 1972 and 1973, the new study suggests that three big migrations between Asia and North America led tyrannosauroids to diversify and eventually reach a gargantuan size in the late Cretaceous Period before going extinct 66 million years ago. 'This discovery of Khankhuuluu forced us to look at the tyrannosaur family tree in a very different light,' said study coauthor Darla Zelenitsky, associate professor within the department of Earth, energy, and environment at the University of Calgary, in an email. 'Before this, there was a lot of confusion about who was related to who when it came to tyrannosaur species. What started as the discovery of a new species ended up with us rewriting the family history of tyrannosaurs.' Tyrannosaurs, known scientifically as Eutyrannosaurians, bring to mind hulking dinosaurs like Tyrannosaurus rex and Tarbosaurus, which weighed multiple metric tons and could take down equally large prey. With short arms and massive heads, they walked on two legs and boasted sharp teeth, Zelenitsky said. But tyrannosaurs didn't start out that way. They evolved from smaller dinosaurs before dominating the landscapes of North America and Asia between 85 million and 66 million years ago, the researchers said. While Tarbosaurus, an ancestor of T. rex, clocked in at between 3,000 and 6,000 kilograms (6,613 pounds and 13,227 pounds), the fleet-footed Khankhuuluu mongoliensis likely weighed only around 750 kilograms (1,653 pounds), spanned just 2 meters (6.5 feet) at the hips and 4 meters (13 feet) in length, according to the study authors. Comparing the two dinosaurs would be like putting a horse next to an elephant —Khankhuuluu would have reached T. rex's thigh in height, Zelenitsky said. 'Khankhuuluu was almost a tyrannosaur, but not quite,' Zelenitsky said. 'The snout bone was hollow rather than solid, and the bones around the eye didn't have all the horns and bumps seen in T. rex or other tyrannosaurs.' Khankhuuluu mongoliensis, or a closely related ancestor species, likely migrated from Asia to North America across a land bridge between Alaska and Siberia that connected the continents 85 million years ago, Zelenitsky said. Because of this migrant species, we now know that tyrannosaurs actually evolved first on the North American continent and remained there exclusively over the next several million years, she said. 'As the many tyrannosaur species evolved on the continent, they became larger and larger.' Due to the poor fossil record, it's unclear what transpired in Asia between 80 million to 85 million years ago, she added. While some Khankhuuluu may have remained in Asia, they were likely replaced later on by larger tyrannosaurs 79 million years ago. Meanwhile, another tyrannosaur species crossed the land bridge back to Asia 78 million years ago, resulting in the evolution of two related but very different subgroups of tyrannosaurs, Zelenitsky said. One was a gigantic, deep-snouted species, while the other known as Alioramins was slender and small. These smaller dinosaurs have been dubbed 'Pinocchio rexes' for their long, shallow snouts. Both types of tyrannosaurs were able to live in Asia and not compete with each other because the larger dinosaurs were top predators, while Alioramins were mid-level predators going after smaller prey — think cheetahs or jackals in African ecosystems today, Zelenitsky said. 'Because of their small size, Alioramins were long thought to be primitive tyrannosaurs, but we novelly show Alioramins uniquely evolved smallness as they had 'miniaturized' their bodies within a part of the tyrannosaur family tree that were all otherwise giants,' Zelenitsky said. One more migration happened as tyrannosaurs continued to evolve, and a gigantic tyrannosaur species crossed back into North America 68 million years ago, resulting in Tyrannosaurus rex, Zelenitsky said. 'The success and diversity of tyrannosaurs is thanks to a few migrations between the two continents, starting with Khankhuuluu,' she said. 'Tyrannosaurs were in the right place at the right time. They were able to take advantage of moving between continents, likely encountering open niche spaces, and quickly evolving to become large, efficient killing machines.' The new findings support previous research suggesting that Tyrannosaurus rex's direct ancestor originated in Asia and migrated to North America via a land bridge and underscore the importance of Asia in the evolutionary success of the tyrannosaur family, said Cassius Morrison, a doctoral student of paleontology at University College London. Morrison was not involved in the new research. 'The new species provides essential data and information in part of the family tree with few species, helping us to understand the evolutionary transition of tyrannosaurs from small/ medium predators to large apex predators,' Morrison wrote in an email. The study also shows that the Alioramini group, once considered distant relatives, were very close cousins of T. rex. What makes the fossils of the new species so crucial is their age — 20 million years older than T. rex, said Steve Brusatte, professor and personal chair of Palaeontology and Evolution at the University of Edinburgh. Brusatte was not involved in the new study. 'There are so few fossils from this time, and that is why these scientists describe it as 'murky,'' Brusatte said. 'It has been a frustrating gap in the record, like if you suspected something really important happened in your family history at a certain time, like a marriage that started a new branch of the family or immigration to a new country, but you had no records to document it. The tyrannosaur family tree was shaped by migration, just like so many of our human families.' With only fragments of fossils available, it's been difficult to understand the variation of tyrannosaurs as they evolved, said Thomas Carr, associate professor of biology at Carthage College in Wisconsin and director of the Carthage Institute of Paleontology. Carr was not involved in the new research. But the new study sheds light on the dinosaurs' diversity and clarifies which ones existed when — and how they overlapped with one another, he said. More samples from the fossil record will provide additional clarity, but the new work illustrates the importance of reexamining fossils collected earlier. 'We know so much more about tyrannosaurs now,' Carr said. 'A lot of these historical specimens are definitely worth their weight in gold for a second look.' When the fossils were collected half a century ago, they were only briefly described at the time, Brusatte said. 'So many of us in the paleontology community knew that these Mongolian fossils were lurking in museum drawers, waiting to be studied properly, and apt to tell their own important part of the tyrannosaur story,' he said. 'It's almost like there was a non-disclosure agreement surrounding these fossils, and it's now expired, and they can come out and tell their story.'

A ‘dragon prince' dinosaur is redrawing the tyrannosaur family tree
A ‘dragon prince' dinosaur is redrawing the tyrannosaur family tree

CNN

time5 hours ago

  • CNN

A ‘dragon prince' dinosaur is redrawing the tyrannosaur family tree

Scientists have identified a previously unknown 86 million-year-old dinosaur species that fills an early gap in the fossil record of tyrannosaurs, revealing how they evolved to become massive apex predators. Researchers analyzing the species' remains have named it Khankhuuluu mongoliensis, which translates to 'dragon prince of Mongolia,' because it was small compared with its much larger relatives such as Tyrannosaurus rex, whose name means 'the tyrant lizard king.' The newly identified dinosaur was the closest known ancestor of tyrannosaurs and likely served as a transitional species from earlier tyrannosauroid species, according to the findings published Wednesday in the journal Nature. Based on a reexamination of two partial skeletons uncovered in Mongolia's Gobi Desert in 1972 and 1973, the new study suggests that three big migrations between Asia and North America led tyrannosauroids to diversify and eventually reach a gargantuan size in the late Cretaceous Period before going extinct 66 million years ago. 'This discovery of Khankhuuluu forced us to look at the tyrannosaur family tree in a very different light,' said study coauthor Darla Zelenitsky, associate professor within the department of Earth, energy, and environment at the University of Calgary, in an email. 'Before this, there was a lot of confusion about who was related to who when it came to tyrannosaur species. What started as the discovery of a new species ended up with us rewriting the family history of tyrannosaurs.' Tyrannosaurs, known scientifically as Eutyrannosaurians, bring to mind hulking dinosaurs like Tyrannosaurus rex and Tarbosaurus, which weighed multiple metric tons and could take down equally large prey. With short arms and massive heads, they walked on two legs and boasted sharp teeth, Zelenitsky said. But tyrannosaurs didn't start out that way. They evolved from smaller dinosaurs before dominating the landscapes of North America and Asia between 85 million and 66 million years ago, the researchers said. While Tarbosaurus, an ancestor of T. rex, clocked in at between 3,000 and 6,000 kilograms (6,613 pounds and 13,227 pounds), the fleet-footed Khankhuuluu mongoliensis likely weighed only around 750 kilograms (1,653 pounds), spanned just 2 meters (6.5 feet) at the hips and 4 meters (13 feet) in length, according to the study authors. Comparing the two dinosaurs would be like putting a horse next to an elephant —Khankhuuluu would have reached T. rex's thigh in height, Zelenitsky said. 'Khankhuuluu was almost a tyrannosaur, but not quite,' Zelenitsky said. 'The snout bone was hollow rather than solid, and the bones around the eye didn't have all the horns and bumps seen in T. rex or other tyrannosaurs.' Khankhuuluu mongoliensis, or a closely related ancestor species, likely migrated from Asia to North America across a land bridge between Alaska and Siberia that connected the continents 85 million years ago, Zelenitsky said. Because of this migrant species, we now know that tyrannosaurs actually evolved first on the North American continent and remained there exclusively over the next several million years, she said. 'As the many tyrannosaur species evolved on the continent, they became larger and larger.' Due to the poor fossil record, it's unclear what transpired in Asia between 80 million to 85 million years ago, she added. While some Khankhuuluu may have remained in Asia, they were likely replaced later on by larger tyrannosaurs 79 million years ago. Meanwhile, another tyrannosaur species crossed the land bridge back to Asia 78 million years ago, resulting in the evolution of two related but very different subgroups of tyrannosaurs, Zelenitsky said. One was a gigantic, deep-snouted species, while the other known as Alioramins was slender and small. These smaller dinosaurs have been dubbed 'Pinocchio rexes' for their long, shallow snouts. Both types of tyrannosaurs were able to live in Asia and not compete with each other because the larger dinosaurs were top predators, while Alioramins were mid-level predators going after smaller prey — think cheetahs or jackals in African ecosystems today, Zelenitsky said. 'Because of their small size, Alioramins were long thought to be primitive tyrannosaurs, but we novelly show Alioramins uniquely evolved smallness as they had 'miniaturized' their bodies within a part of the tyrannosaur family tree that were all otherwise giants,' Zelenitsky said. One more migration happened as tyrannosaurs continued to evolve, and a gigantic tyrannosaur species crossed back into North America 68 million years ago, resulting in Tyrannosaurus rex, Zelenitsky said. 'The success and diversity of tyrannosaurs is thanks to a few migrations between the two continents, starting with Khankhuuluu,' she said. 'Tyrannosaurs were in the right place at the right time. They were able to take advantage of moving between continents, likely encountering open niche spaces, and quickly evolving to become large, efficient killing machines.' The new findings support previous research suggesting that Tyrannosaurus rex's direct ancestor originated in Asia and migrated to North America via a land bridge and underscore the importance of Asia in the evolutionary success of the tyrannosaur family, said Cassius Morrison, a doctoral student of paleontology at University College London. Morrison was not involved in the new research. 'The new species provides essential data and information in part of the family tree with few species, helping us to understand the evolutionary transition of tyrannosaurs from small/ medium predators to large apex predators,' Morrison wrote in an email. The study also shows that the Alioramini group, once considered distant relatives, were very close cousins of T. rex. What makes the fossils of the new species so crucial is their age — 20 million years older than T. rex, said Steve Brusatte, professor and personal chair of Palaeontology and Evolution at the University of Edinburgh. Brusatte was not involved in the new study. 'There are so few fossils from this time, and that is why these scientists describe it as 'murky,'' Brusatte said. 'It has been a frustrating gap in the record, like if you suspected something really important happened in your family history at a certain time, like a marriage that started a new branch of the family or immigration to a new country, but you had no records to document it. The tyrannosaur family tree was shaped by migration, just like so many of our human families.' With only fragments of fossils available, it's been difficult to understand the variation of tyrannosaurs as they evolved, said Thomas Carr, associate professor of biology at Carthage College in Wisconsin and director of the Carthage Institute of Paleontology. Carr was not involved in the new research. But the new study sheds light on the dinosaurs' diversity and clarifies which ones existed when — and how they overlapped with one another, he said. More samples from the fossil record will provide additional clarity, but the new work illustrates the importance of reexamining fossils collected earlier. 'We know so much more about tyrannosaurs now,' Carr said. 'A lot of these historical specimens are definitely worth their weight in gold for a second look.' When the fossils were collected half a century ago, they were only briefly described at the time, Brusatte said. 'So many of us in the paleontology community knew that these Mongolian fossils were lurking in museum drawers, waiting to be studied properly, and apt to tell their own important part of the tyrannosaur story,' he said. 'It's almost like there was a non-disclosure agreement surrounding these fossils, and it's now expired, and they can come out and tell their story.'

DOWNLOAD THE APP

Get Started Now: Download the App

Ready to dive into the world of global news and events? Download our app today from your preferred app store and start exploring.
app-storeplay-store