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CNN
a day ago
- Science
- CNN
‘Dragon prince' dinosaur discovery is changing how scientists understand T. rex
Sign up for CNN's Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. CNN — 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.' Multiple migrations over millions of years 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.' Revisiting a decades-old find 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.'
The Australian
a day ago
- Science
- The Australian
New T-Rex ancestor discovered in drawers of Mongolian institute
Misidentified bones that languished in the drawers of a Mongolian institute for 50 years belong to a new species of tyrannosaur that rewrites the family history of the mighty T-Rex, scientists said Wednesday. This slender ancestor of the massive Tyrannosaurus Rex was around four metres (13 feet) long and weighed three quarters of a tonne, according to a new study in the journal Nature. "It would have been the size of a very large horse," study co-author Darla Zelenitsky of Canada's University of Calgary told AFP. The fossils were first dug up in southeastern Mongolia in the early 1970s but at the time were identified as belonging to a different tyrannosaur, Alectrosaurus. For half a century, the fossils sat in the drawers at the Institute of Paleontology of the Mongolian Academy of Sciences in the capital Ulaanbaatar. Then PhD student Jared Voris, who was on a trip to Mongolia, started looking through the drawers and noticed something was wrong, Zelenitsky said. It turned out the fossils were well-preserved, partial skeletons of two different individuals of a completely new species. "It is quite possible that discoveries like this are sitting in other museums that just have not been recognised," Zelenitsky added. - 'Messy' family history - They named the new species Khankhuuluu mongoliensis, which roughly means the dragon prince of Mongolia because it is smaller than the "king" T-Rex. Zelenitsky said the discovery "helped us clarify a lot about the family history of the tyrannosaur group because it was really messy previously". The T-Rex represented the end of the family line. It was the apex predator in North America until 66 million years ago, when an asteroid bigger than Mount Everest slammed into the Gulf of Mexico. Three quarters of life on Earth was wiped out, including all the dinosaurs that did not evolve into birds. Around 20 million years earlier, Khankhuuluu -- or another closely related family member -- is now believed to have migrated from Asia to North America using the land bridge that once connected Siberia and Alaska. This led to tyrannosaurs evolving across North America. Then one of these species is thought to have crossed back over to Asia, where two tyrannosaur subgroups emerged. One was much smaller, weighing under a tonne, and was nicknamed Pinocchio rex for its long snout. The other subgroup was huge and included behemoths like the Tarbosaurus, which was only a little smaller than the T-rex. One of the gigantic dinosaurs then left Asia again for North America, eventually giving rise to the T-Rex, which dominated for just two million years -- until the asteroid struck. dl/gil
News.com.au
2 days ago
- Science
- News.com.au
New T-Rex ancestor discovered in drawers of Mongolian institute
Misidentified bones that languished in the drawers of a Mongolian institute for 50 years belong to a new species of tyrannosaur that rewrites the family history of the mighty T-Rex, scientists said Wednesday. This slender ancestor of the massive Tyrannosaurus Rex was around four metres (13 feet) long and weighed three quarters of a tonne, according to a new study in the journal Nature. "It would have been the size of a very large horse," study co-author Darla Zelenitsky of Canada's University of Calgary told AFP. The fossils were first dug up in southeastern Mongolia in the early 1970s but at the time were identified as belonging to a different tyrannosaur, Alectrosaurus. For half a century, the fossils sat in the drawers at the Institute of Paleontology of the Mongolian Academy of Sciences in the capital Ulaanbaatar. Then PhD student Jared Voris, who was on a trip to Mongolia, started looking through the drawers and noticed something was wrong, Zelenitsky said. It turned out the fossils were well-preserved, partial skeletons of two different individuals of a completely new species. "It is quite possible that discoveries like this are sitting in other museums that just have not been recognised," Zelenitsky added. - 'Messy' family history - They named the new species Khankhuuluu mongoliensis, which roughly means the dragon prince of Mongolia because it is smaller than the "king" T-Rex. Zelenitsky said the discovery "helped us clarify a lot about the family history of the tyrannosaur group because it was really messy previously". The T-Rex represented the end of the family line. It was the apex predator in North America until 66 million years ago, when an asteroid bigger than Mount Everest slammed into the Gulf of Mexico. Three quarters of life on Earth was wiped out, including all the dinosaurs that did not evolve into birds. Around 20 million years earlier, Khankhuuluu -- or another closely related family member -- is now believed to have migrated from Asia to North America using the land bridge that once connected Siberia and Alaska. This led to tyrannosaurs evolving across North America. Then one of these species is thought to have crossed back over to Asia, where two tyrannosaur subgroups emerged. One was much smaller, weighing under a tonne, and was nicknamed Pinocchio rex for its long snout. The other subgroup was huge and included behemoths like the Tarbosaurus, which was only a little smaller than the T-rex. One of the gigantic dinosaurs then left Asia again for North America, eventually giving rise to the T-Rex, which dominated for just two million years -- until the asteroid struck. dl/gil
Malay Mail
2 days ago
- Science
- Malay Mail
New T-Rex ancestor discovered in drawers of Mongolian institute
PARIS, June 12 — Misidentified bones that languished in the drawers of a Mongolian institute for 50 years belong to a new species of tyrannosaur that rewrites the family history of the mighty T-Rex, scientists said yesterday. This slender ancestor of the massive Tyrannosaurus Rex was around four metres (13 feet) long and weighed three quarters of a tonne, according to a new study in the journal Nature. 'It would have been the size of a very large horse,' study co-author Darla Zelenitsky of Canada's University of Calgary told AFP. The fossils were first dug up in southeastern Mongolia in the early 1970s but at the time were identified as belonging to a different tyrannosaur, Alectrosaurus. For half a century, the fossils sat in the drawers at the Institute of Palaeontology of the Mongolian Academy of Sciences in the capital Ulaanbaatar. Then PhD student Jared Voris, who was on a trip to Mongolia, started looking through the drawers and noticed something was wrong, Zelenitsky said. It turned out the fossils were well-preserved, partial skeletons of two different individuals of a completely new species. 'It is quite possible that discoveries like this are sitting in other museums that just have not been recognised,' Zelenitsky added. 'Messy' family history They named the new species Khankhuuluu mongoliensis, which roughly means the dragon prince of Mongolia because it is smaller than the 'king' T-Rex. Zelenitsky said the discovery 'helped us clarify a lot about the family history of the tyrannosaur group because it was really messy previously'. The T-Rex represented the end of the family line. It was the apex predator in North America until 66 million years ago, when an asteroid bigger than Mount Everest slammed into the Gulf of Mexico. Three quarters of life on Earth was wiped out, including all the dinosaurs that did not evolve into birds. Around 20 million years earlier, Khankhuuluu — or another closely related family member — is now believed to have migrated from Asia to North America using the land bridge that once connected Siberia and Alaska. This led to tyrannosaurs evolving across North America. Then one of these species is thought to have crossed back over to Asia, where two tyrannosaur subgroups emerged. One was much smaller, weighing under a tonne, and was nicknamed Pinocchio rex for its long snout. The other subgroup was huge and included behemoths like the Tarbosaurus, which was only a little smaller than the T-rex. One of the gigantic dinosaurs then left Asia again for North America, eventually giving rise to the T-Rex, which dominated for just two million years — until the asteroid struck. — AFP
BBC News
2 days ago
- Science
- BBC News
New species of dinosaur discovered that 'rewrites' T.rex family tree
Scientists have discovered a new species of dinosaur - in the collection of a Mongolian museum - that they say "rewrites" the evolutionary history of concluded that two 86 million-year-old skeletons they studied belonged to a species that is now the closest known ancestor of all tyrannosaurs - the group of predators that includes the iconic researchers named the species Khankhuuluu (pronounced khan-KOO-loo) mongoliensis, meaning Dragon Prince of discovery, published in Nature, is a window into how tyrannosaurs evolved to become powerful predators that terrorised North America and Asia until the end of the reign of the dinosaurs. "'Prince' refers to this being an early, smaller tyrannosauroid," explained Prof Darla Zelenitsky, a palaeontologist from the University of Calgary in Canada. Tyrannosauroids are the superfamily of carnivorous dinosaurs that walked on two first tyrannosauroids though were tiny. PhD student Jared Voris, who led the research with Prof Zelenitsky, explained: "They were these really small, fleet-footed predators that lived in the shadows of other apex predatory dinosaurs."Khankhuuluu represents an evolutionary shift - from those small hunters that scampered around during the Jurassic period - to the formidable giants, including T-rex. It would have weighed about 750kg, while an adult could have weighed as much as eight times that, so "this is a transitional [fossil]," explained Prof Zelenitsky, "between earlier ancestors and the mighty tyrannosaurs"."It has helped us revise the tyrannosaur family tree and rewrite what we know about the evolution of tyrannosaurs," she added. The new species also shows early evolutionary stages of features that were key to the tyrannosaurs' tyranny, including skull anatomy that gave it a strong jaw. Jared Voris explained: "We see features in its nasal bone that eventually gave tyrannosaurs those very powerful bite forces."The evolution of such powerful jaws allowed T-rex to pounce on larger prey, and even bite through last meal was two baby dinosaursFossil reveals 240 million year-old 'dragon'Solving the mystery of a dinosaur mass graveThe two partial skeletons that the team examined in this study were first discovered in Mongolia back in the early 1970s. They were initially assigned to an existing species, known as Alectrosaurus, but when Mr Voris examined them, he identified the Tyrannosaur-like features that set it apart."I remember getting a text from him - that he thought this was a new species," recalled Prof Zelenitsky. The fact that this group of dinosaurs were able to move between North America and Asia - via land bridges that connected Siberia and Alaska at the time - also helped them to find and occupy different Voris explained: "That movement back and forth between the continents basically pushed the evolution of different tyrannosaur groups" over millions of Zelinitsky added: "This discovery shows us that, before tyrannosaurs became the kings, they were they were princes."
