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
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The Australian
2 days ago
- 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
- 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
ABC News
5 days ago
- ABC News
First reported sauropod fossil stomach contents show the dinosaurs were 'bulk feeders' of plants
Fossilised dinosaur guts unearthed in outback Queensland could back a long-standing theory on the diet of sauropods, the biggest reptiles to roam the planet. For nearly 150 years, it's been thought that sauropods — a group of four-legged, long-necked and relatively small-headed creatures like the Brachiosaurus — were herbivores. This was based on several assumptions, including their flat teeth and overall large body that would make it hard for them to chase down moving prey. But direct evidence of what these animals ate has been lacking. Now, in today's issue of the journal Current Biology, researchers report their first ever discovery of fossilised intestinal contents — referred to as "cololite" — from a sauropod. The cololite was found inside a relatively complete skeleton of Diamantinasaurus matildae in 2017 at Belmont Station, near Winton, with much of it sealed over by a layer of mineralised skin. "What was really exciting about it [the gut fossil] is in places you could see the folds of the gut," Belmont Station owner and palaeontologist David Elliott said. An analysis of the fossil showed a young Diamantinasaurus specimen, nicknamed "Judy", whose gut contained small voids — impressions left behind by decomposed plants. Palaeontologist and study lead author Stephen Poropat, from Curtin University, said Judy seemed to have eaten plants from a range of heights. "There's relatives of modern-day monkey puzzle trees, we have seed ferns, which are a totally extinct group," he said. "And we also have leaves from angiosperms, which are flowering plants. Back in the Cretaceous period when Judy was alive, they would have looked somewhat similar to modern-day magnolias." The study has shown not only what a sauropod like Diamantinasaurus ate, but how they ate too. Uppsala University palaeontologist Martin Qvarnström, who was not involved in the study, said the size of the food fragments found in Judy's gut supported the idea that sauropods fermented their food rather than chewed it. "The tricky part here was proving the plant material wasn't just random debris, and here the authors make a strong case, especially with evidence of the plants being sealed inside mineralised skin," he said. "The preservation of both gut contents and skin is unusual." Diamantinasaurus were first described in 2009 and lived in the mid Cretaceous, about 101 to 94 million years ago. They were part of the sauropod group of dinosaurs, which lived from about 201 million years ago until the end of the age of dinosaurs about 66 million years ago. When Diamantinasaurus lived, Australia was closer to the South Pole, and what is now outback would have been a wet flood plain covered in conifers, gingkos, seed ferns and other plants — plenty of food for a growing dinosaur. The largest-known sauropod eggs are smaller than a soccer ball so when the baby reptiles hatched, they may have been no bigger than 50 centimetres from tip to tail. Dr Poropat said they would then have to grow very fast to avoid falling victim to predators. "I often think about sauropods in similar context of turtles, where turtle mothers will lay a large number of eggs … and then basically abandon them," he said. "And when the babies hatch, they're ready to go. "For sea turtles that's the sea, but for sauropods they might have just needed to get into a forest … where they were surrounded by food and also had places to shelter." Dr Poropat said Judy was a sub-adult and probably measured about 11 to 12 metres. A fully grown Diamantinasaurus would have reached about 16m long. He theorised Judy (who is referred to as "she" although her gender isn't known) was in a transition phase where she was eating some of the plants she consumed when she first hatched. "We actually speculate that Judy might have had a diet different to an adult Diamantinasaurus," he said. "She couldn't reach up into the tops of conifers, but also she's starting to eat the conifer foliage that is targeted maybe more so by adults. "So it's kind of cool to think that sauropods would have changed their diet as they grew up, just as many animals do." Miami Frost Museum of Science palaeontologist Cary Woodruff, who specialises in sauropods but was not involved in the study, said capturing this transitionary period and its implications for sauropod growth were the crowning jewel of the new study. "Previous studies have shown that in some species, the young had pointed snouts, likely for selective feeding, and when they grew up, they had broad 'muzzles' for grazing," he said. "And in some, the young had teeth designed for both soft and coarse vegetation. Dr Woodruff said Judy captured a "moment in time" where the Diamantinasaurus had this Swiss Army knife. Mr Elliott said Judy the dinosaur, who scientists named after his wife, was likely to be given her own exhibit at a new building at the Australian Age of Dinosaurs museum in Winton. He said galleries were currently being designed and Judy was a prime candidate for a skeleton reconstruction. "We want to tell the story of Australian evolution as how from the very first life forms how Australian life has changed over millions of years."
