Greater than 85 million years in the past, a smaller-bodied ancestor of the Tyrannosaurus rex roamed the plains of Mongolia. The dinosaur’s id was unknown — till now.
In a research revealed Wednesday in Nature, scientists describe the identification of a brand new tyrannosauroid named Khankhuuluu mongoliensis. Apex predators, together with the T. rex, ultimately arose from these smaller-bodied tyrannosauroids, the research’s researchers stated.
“This species, Khankhuuluu, is the missing link between smaller and earlier forms and the larger apex predatory tyrannosaurs,” paleontologist Darla Zelenitsky, a professor on the College of Calgary and research co-author, advised CBS Information.
Riley Brandt, College of Calgary
The Khankhuuluu’s skeleton was found in Mongolia within the Gobi Desert in 1972 or 1973, however wasn’t studied scientifically till a couple of years later, Zelenitsky stated. The stays had been recognized by Mongolian paleontologist Altangerel Perle as Alectrosaurus olsoni, one other obscure species. After it was misidentified, the bones turned a part of a museum assortment and had been comparatively untouched for nearly 50 years.
Known as mid-grade tyrannosauroids, these smaller-bodied predators had been evolutionary intermediates, the research discovered. In the course of the interval when Khankhuuluu lived in Mongolia, the tyrannosaurs started rising bigger and taking over the options of apex predators. Not a lot else is understood about these elusive tyrannosauroids because of fragmentary fossil stays, however researchers stated the dinosaurs weighed round 1,700 kilos. They had been one of many bigger predators within the ecosystem on the time.
“It’s essentially the immediate ancestor of the tyrannosaur family,” Zelenitsky stated.
A shock discovery
College of Calgary postdoctoral scholar and research co-author Jared Voris traveled to Mongolia a couple of years earlier to analysis the bones of assorted tyrannosaurs and, within the course of, gained entry to see the bones of what they’d later decide are the Khankhuuluu.
Voris thought the stays may very well be one thing necessary, as he usually noticed references to the specimens pop up, however after he began analyzing the bones, he knew it may very well be one thing particular. Whereas finding out the person traits of the bones, one of many issues he observed was that the Khankhuuluu’s enamel couldn’t crush bone, Voris stated, a defining attribute of the bigger apex predatory Tyrannosaurus.
“This animal had features we had never seen before in more of our iconic tyrannosaurs,” Voris stated.
He texted Zelenitsky from Mongolia that he “thought it could be a new species.” Zelenitsky stated she responded, “I said, great going, keep looking at this so we can be sure this is a new species.”
Picture: Julius Csotonyi
The 2 paleontologists aren’t new to groundbreaking scientific discoveries — they’ve had a number of. In 2023, Zelenitsky was a part of a group that recognized a Tyrannosaurus fossil with a meal in its abdomen, and Voris found a brand new species of tyrannosaurid dinosaur, Thanatotheristes degrootorum — whose genus title interprets to “Reaper of Death.”
“Rewriting a family history of tyrannosaurs”
These Asian tyrannosauroids ultimately crossed over into North America utilizing a northern land bridge between Alaska and Siberia, Zelenitsky stated. Dinosaurs used these land bridges, which appeared periodically over the previous 100 million years, to journey between Asia and North America.
And from it, these tyrannosauroids advanced and morphed into apex predators. T. rex is the deadliest land predator ever to stay, and there has lengthy been a fascination with the dinosaur that has been extinct for about 66 million years.
Picture credit score: Jared Voris
The research co-authors stated the brand new identification reveals there are nonetheless huge discoveries to be made in science. “What really started just as a discovery of a new species ended up with us kind of rewriting a family history of tyrannosaurs,” Zelenitsky stated.
