The main killer of the Jurassic and Cretaceous lands was the carnivorous dinosaur. These thieves walked on two legs, had strong legs fastened with sharp teeth and obtained species from groups called tyrannosaurs, spinosaurs and carcharodontosaurs.
Tyrannosaurus rex, the goat -eating tyrannosaur that ate goats from the Jurassic Park movie, was North America’s biggest killer before the dinosaurs became extinct at the end of the Cretaceous Period. Although T. rex is the only species of meat -eating dinosaur that has dominated various ecosystems at different times over 130 million years of the dinosaur kingdom.
During the Cretaceous, most of the tallest predators grown in North America and Asia were carcharodontosaurs (shark -toothed dinosaurs) or tyrannosaurs (tyrant dinosaurs). The first part of the Cretaceous was dominated by carcharodontosaurs, and later tyrannosaurs transformed them into high -ranking thieves until the end of the Cretaceous.
Kind of new
Today, two new species of these great Cretaceous predators have been identified – a tyrannosaur from Canada and a carcharodontosaur from Uzbekistan. I was lucky to be part of their training. These two concepts, although unrelated, have several differences.
In 2019, paleontologists Jared Voris and Kohei Tanaka – two men who studied in my lab at the University of Calgary – visited the museums to look at the fossils deposited in the collections. . Voris visited the Royal Tyrrell Museum in Drumheller, Alta., And Tanaka visited the State Geological Museum in Uzbekistan.
Everyone received a piece of coal that they thought was important, even though it had been forgotten. The two monarchs are known in the ancient Cretaceous rocks of their land, and have lived in museum collections for at least ten years without knowledge.
After months of confinement, these fossils became the newest part of the fish -eating dinosaur, never before seen by science. That is why we need to define them carefully, giving each one its own name.
We called the new tyrannosaur species Thanatotheristes degrootorum, which means “the cutter of death.” The name draws inspiration from his predatory work in the 80 -million -year -old ecosystem and for the first discoverer of fossil bones, an Alberta rancher named John DeGroot.
On the other hand, we named the carcharodontosaur Ulughbegsaurus uzbekistanensis after Ulugh Beg, the first historian and astronomer in Uzbekistan.
Both types can be seen from the small skull bones, but the rest of their bones are not visible. The most prominent bones are the jawbone – the upper and lower jaw of Thanatotheristes and the jawbone of Ulughbegsaurus.
From the jaws, it was seen that the two species were noble and had much in common. We were able to see how large their bodies were from these bones that were preserved. Measuring from the tip of the nose to the tip of the tail, there are two types of about eight meters in length – the length of a standard school bus.
In these two studies, we learned that Thanatotheristes and Ulughbegsaurus are each, by far, the biggest thief of their ecosystem. It’s hard not to find a single major killer in every ecosystem in the past, because a large number of food -eating dinosaurs have evolved unnoticed, such as living herbivores.
Most other species of thieves from this ecosystem are small, less than three meters long. In fact, Uzbekistan’s ancient ecosystem is home to a small tyrannosaur species depleted by the large Ulughbegsaurus.
The rise and death of high -profile thieves
About 90 million years ago, carcharodontosaur species became extinct – Ulughbegsaurus was one of the last of its kind. Their demise left a gap in North America and Asia for new mass murderers to grow and take over. Tyrannosaurs, for the most part, have been knee -deep in a carcharodontosaur for the past tens of millions of years, they have finally made their game.
Between 90 and 80 million years ago, tyrannosaur species began to grow in physical size. Thanatotheristes are one of the earliest species of these large tyrannosaurs, living about 80 million years ago in prehistoric Alberta.
Thanatotheristes and his family were among the ancestors who led the larger tyrannosaur species, such as the 12 -meter -long Tyrannosaurus rex. These major species dominated the Cretaceous ecosystems of North America and Asia for the past 10 million years before a catastrophic event wiped out the dinosaurs.
Who is king more than a tyrannosaurus? Uzbek fossils show a new high dino
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Directions: The discovery of two giant dinosaur species to solve the mystery of the missing apex thieves in North America and Asia (2022, April 11) Retrieved 11 April 2022 from https://phys.org/ news/2022-04-discovery-giant-dinosaur -species-mystery.html
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