Illustration of Ulughbegsaurus Uzbekistanensis the "shark-toothed dinosaur", who lived about 90 million years ago in what is now Uzbekistan. (Image credit: Julius Csotonyi)
According to new research on the jawbone of the giant predator, about 90 million years ago, a huge meat-eating dinosaur with shark-like teeth and serrated shark-like teeth roamed what is now Uzbekistan.
The beast, which measured 26 feet (8 meters), weighed in at 2,200 pounds (1,006 kilograms). This made it larger than an African elephant and heavier that a bison. It was named Ulughbegsaurus uzbekistanensis by researchers after Ulugh Beg (15th century astronomer, mathematician, and sultan of what is now Uzbekistan).
Scientists were shocked to discover that the dinosaur was twice as long and five times more heavy than the ecosystem's apex predator, a Tyrannosaurus.
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Researchers found the jawbone in Uzbekistan's Kyzylkum Desert during the 1980s. In 2019, they rediscovered it in a Uzbekistan museum collection.
U. uzbekistanensis' partial jawbone is sufficient to indicate that the animal may have been a carcharodontosaur or "shark-toothed dinosaur". These carnivores were competitors and cousins of Tyrannosaurus Rex, the most well-known tyrannosaur species.
According to Darla Zelenitsky (associate professor of paleobiology at University of Calgary), the two dinosaur groups looked very similar. However, carcharodontosaurs were more slim and light-built than heavyset tyrannosaurs. Carcharodontosaurs weighed more than tyrannosaur dinosaurs, and reached weights of over 13,200 pounds (6,000 kilograms). Around 90 million to 80 millions years ago, the carcharodontosaurs vanished and the tyrannosaurs took over as the top predators in Asia.
Two late Cretaceous dinosaur predators were a carcharodontosaur and a Tyrannosaur: (Image credit: Darla Zelenitsky)
Researchers noted that this is the first known carcharodontosaur dinosaurus from Central Asia. The team noted that Paleontologists knew that Timurlengia, a tyrannosaur, lived in the same place and time as U. uzbekistanensis. However, Timurlengia measured 13 feet (4m) in height and weighed 375 pounds (170kg) in weight. This suggests that U. Uzbekistanensis may have been the dominant predator in the area, eating up long-necked sauropods, and ostrich-like dinos.
"Our discovery suggests that carcharodontosaurs are still dominant predators of Asia 90 million years ago," Kohei Tanaka, a lead researcher at the Graduate School of Life and Environmental Sciences, at the University of Tsukuba, Japan, said to Live Science via email.
Illustration of the huge carcharodontosaur Ulughbegsaurus interacting with the smaller Tyrannosaur Timurlengia. (Image credit: Julius Csotonyi)
Peter Makovicky from the University of Minnesota, who is a professor of paleontology, said that U. uzbekistanensis would have been at the top of the local food chains. Makovicky stated that the bone was so large that it would have made a predatory dinosaur, and therefore be the most powerful predator in its ecosystem.
Image 1 of 4. This piece of jawbone is all the paleontologists know about the dinosaur Ulughbegsaurus. (Image credit Tanaka et. al 2021. Image 2 of 4. This map shows the location where Ulughbegsaurus fossils were found in Uzbekistan. (Image credit: Tanaka et al. 2021. Image 3 of 4. A reconstruction of Ulughbegsaurus’s upper jaw and teeth. (Image credit to Dinosaur Valley Studios. Image 4 of 4 Stud researchers Kohei Tanaka and Darla Zelenitsky. Image credit: University of Calgary
According to the team, U. uzbekistanensis is the only known instance of a carcharodontosaur living with a tyrannosaur before those dinosaurs went extinct. The team discovered that U. uzbekistanensis had unique bony bumps over its teeth. It also had bony ridges along its jaws that were very similar to Thanatotheristes, a 79.5 million-year old tyrannosaur whose name means "reaper of death") from Canada. Zelenitsky suggested that it could be convergent evolution, where species are not closely related develop similar characteristics.
The study was published online in Royal Society Open Science on Wednesday, September 8.
Original publication on Live Science