About 90 million years ago, a giant apex predator, a meat-eating dinosaur with shark-like toothed teeth, roamed what is now Uzbekistan, according to a new study on the behemoth’s jaw.
The eight-meter-long (8-meter) beast weighed 2,200 pounds (1,000 kilograms), making it longer than an African elephant and heavier than a bison.
The researchers called him Ulughbegsaurus uzbekistanensis, after Ulugh Beg, astronomer, mathematician and sultan of century XV of present Uzbekistan.
What surprised scientists was that the dinosaur was much larger (twice as long and more than five times heavier) than the apex predator of its ecosystem: a tyrannosaurus, the researchers found.
Related: The 10 Coolest Dinosaur Discoveries of 2020
The piece of jaw bone was found in the Kyzylkum Desert of Uzbekistan in the 1980s, and researchers rediscovered it in 2019 in a collection of museums in Uzbekistan.
(Juli Csotonyi)
At the top: an illustration of the huge Ulughbegsaurus carcarodontosaurus with the smaller tyrannosaurus Timurlengia.
The partial jaw of U. uzbekistanensis it is enough to suggest that the animal was a carcarodontosaurus or a “shark-toothed” dinosaur. These carnivores were cousins and competitors of tyrannosaurs, the most famous species of which is Tyrannosaurus rex.
The two groups of dinosaurs were quite similar, but carcarodontosaurs were generally slimmer and slightly constructed than heavy-weight tyrannosaurs, said researcher Darla Zelenitsky, an associate professor of paleobiology at the University of Calgary.
However, carcarodontosaurs used to be larger than tyrannosaurus dinosaurs, weighing more than 6,000 kg (13,200 pounds). Then, about 90 million to 80 million years ago, carcodontosaurs disappeared and tyrannosaurs grew in size, taking over as apex predators in Asia and North America.
The researchers noted that the new find is the first carcarodontosaur dinosaur discovered in Central Asia.
Paleontologists already knew that the tyrannosaurus Timurlengia he lived at the same time and in the same place, but with a length of 4 m (13 feet) and about 170 kg (375 lbs) of weight, Timurlengia it was several times smaller than U. uzbekistanensis, suggesting this U. uzbekistanensis it was the apex predator in that ecosystem, engulfing horned dinosaurs, long-necked sauropods and ostrich-like dinosaurs in the neighborhood, the team said.
(Dinosaur Valley Studios)
At the top: a reconstruction of the upper jaw and teeth of Ulughbegsaurus.
“Our discovery indicates that carcodontosaurs were still dominant predators in Asia 90 million years ago,” study lead researcher Kohei Tanaka, an assistant professor at the Graduate School of Life, told Live Science in an email. and Environmental Sciences from Tsukuba University in Japan.
Peter Makovicky, a professor of paleontology at the University of Minnesota who did not participate in the study, agreed U. uzbekistanensis it was probably at the top of the local food chain.
“I think this bone is so big that it would have been a very large predatory dinosaur and most likely the apex predator of its ecosystem,” Makovicky told Live Science.
He U. uzbekistanensis the finding is the latest known occurrence of a carcarodontosaurus and a tyrannosaurus living together before the carcarodontosaurs became extinct, the team said.
The team found it U. uzbekistanensis it has unique bony bumps above the teeth. However, it also has bony ridges on the sides of its jaw that were similar to the 79.5 million-year-old tyrannosaurus. Thanatotheristes degrootorum (whose name means “reaper of death”) of what is now Canada.
It is unclear why both species have these mountain ranges, but perhaps it is a case of convergent evolution, when species that are not closely related evolve to have similar characteristics, Zelenitsky said.
The study was published online Wednesday (September 8) in the journal Royal Society Open Science.
Related content: