IELTS READING – DINOSAURS AND THE SECRETS THEY STILL HOLD S14GT5
IELTS READING
DINOSAURS AND THE SECRETS THEY STILL HOLD
Dinosaur expert Dr Steve Brusatte continues to investigate the mysteries surrounding these fascinating prehistoric creatures
I was recently part of a team of palaeontologists that discovered a new dinosaur. Living in what is now China, the species would have resembled a strange bird. It was about the size of a sheep and covered in feathers, with a sharp beak that it probably used to crack open shellfish.
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It was given the formal scientific name Tongtianlong, but we called it ‘Mud Dragon’ because its skeleton was discovered in rock that had hardened from ancient mud. It seems that the creature got trapped in the mud and died. Then its fossil remains were found a few months ago when workmen were excavating a site in order to build a school.
It is every dinosaur-obsessed child’s dearest wish to discover and name a completely new species. In fact what my colleagues and I did wasn’t that unusual. New dinosaurs are appearing everywhere these days – about 50 each year. And this pace shows no signs of slowing, as different areas continue to open up to fossil hunters and a fresh generation of scientists comes of age. Because of this plentiful supply of new fossils, we now know more about dinosaurs than we do about many modern animals. But there are still many unsolved mysteries.
Dinosaurs didn’t start out as huge monsters like Tyrannosaurus Rex. Instead they evolved from a group of angular, cat-sized reptiles called dinosauromorphs. These creatures remained small and rare for millions of years until they developed into dinosaurs. The boundary between dinosauromorphs and dinosaurs is becoming less and less distinct with each new discovery that’s made, but what’s becoming clear is that it took millions of years for these first dinosaurs to spread around the world, grow to huge sizes and become truly dominant.
Some discoveries in the 1970s, like the agile and strangely bird-like Deinonychus, proved that dinosaurs were far more dynamic and intelligent than previously thought. Some palaeontologists even proposed that they were warm-blooded creatures like modern birds with a constant high body temperature that they controlled internally, rather than from warming themselves by lying in the sun. A few decades later opinions are still mixed. The problem is that dinosaurs can’t be observed. Palaeontologists must rely on studying fossils. Some results are convincing: we know from studying their bones that dinosaurs had rapid growth rates, just like modern, warm-blooded animals. Other palaeontologists, however, use the same fossils to suggest that dinosaurs were somewhere between cold-blooded reptiles and warm-blooded birds. More studies are needed to provide more clarity.
The discovery of Deinonychus with its long arms, skinny legs, arched neck and big claws on its feet, helped to strengthen the theory that birds evolved from dinosaurs. In the late 1990s, the discovery of thousands of feather- covered dinosaurs closed the argument.
