PASSAGE 3 How a prehistoric predator took to the skies

READING PASSAGE 3
You should spend about 20 minutes on Questions 27-40, which are based on Reading Passage 3 on spages 9 and 10.

How a prehistoric predator took to the skies
Is that a bird in the sky? A plane? No, it’s a pterosaur. Kate Thomas meets Professor Matthew Wilkinson, who built a life-size model to find out how this prehistoric predator ever got off the ground

Pterosaurs existed from the Triassic period, 220 million years ago, to the end of the Cretaceous period, 65 million years ago, when South America pulled away from Africa and the South Atlantic was formed. They are among the least understood of all the extinct reptiles that once spent their lives in the skies while the dinosaurs dominated the land. Pterosaurs had no feathers, but at least part of their bodies was covered in hair, not unlike bats. Some believe this is an indication they were warm-blooded. Researchers also debate \Nhether pterosaurs travelled on the ground by walking on their hind legs, like birds, or by using all fours, relying on their threetoed front feet as well as their four-toed rear feet.

Pterosaurs were vertebrates, meaning they were the first species possessing backbones to become airborne, but scientists have never quite understood their flight technique. How, they wondered, did such a heavy creature ever manage to take off? How could a wing that appears to have been supported by fine, hollow bones have carried one into the sky? Then came the discovery of a site in Brazil’s Araripe basin. Here, not only were hundreds of fossils of amphibians1 and other reptiles found, but archaeologists unearthed a number of very well­ preserved pterosaurs. The anhanguera – a fisheating sub-species of pterosaur that ruled the skies in the Cretaceous period – was among them. With a wingspan of up to 12 metres, they would have made an amazing sight in the sky – had any human been there to witness it. ‘I’ve been studying pterosaurs for about eight years now,’ says Dr Matthew Wilkinson, a professor of zoology at Cambridge University. With an anhanguera fossil as his model, Wilkinson began gradually reconstructing its skeletal structure in his Cambridge studio. The probability of finding three-dimensional pterosaur fossils anywhere is slim. That was quite a find,’ he says. Their bones are usually crushed to dust.’ Once the structure was complete, it inspired him to make a robot version as a way to understand the animal’s locomotion. With a team of model-makers, he has built a remote- controlled pterosaur in his studio. ‘Fossils show just how large these creatures were. I’ve always been interested in how they managed to launch themselves, so I thought the real test would be to actually build one and fly it.’

Wilkinson hasn’t been alone in his desire to recreate a prehistoric beast. Swiss scientists recently announced they had built an amphibious robot that could walk on land and swim in water using the sort of backbone movements that must have been employed by the first creatures to crawl from the sea. But Wilkinson had the added complication of working out his beast’s flight technique. Unlike those of bats or flying squirrels, pterosaur wings – soft, stretchy membranes of skin tissue – are thought to have reached from the chest right to the ankle, reinforced by fibres that stiffened the wing and prevented tearing. Smaller subspecies flapped their wings during takeoff. That may have explained the creatures’ flexibility, but it did not answer the most pressing question: how did such heavy animals manage to launch themselves into the sky? Working with researchers in London and Berlin, Wilkinson began to piece together the puzzle.

It emerged that the anhanguera had an elongated limb called the pteroid. It had previously been thought the pteroid pointed towards the shoulder of the creature and supported a soft forewing in front of the arm. But if that were the case, the forewing would have been too small and ineffectual for flight. However, to the surprise of many scientists, fossils from the Araripe basin showed the pteroid possibly faced the opposite way, creating a much greater forewing that would have caught the air, working in the same way as the flaps on the wings of an aeroplane. So, with both feet on the ground, the anhanguera might have simply faced into the wind, spread its wings and risen up into the sky. Initial trials in wind tunnels proved the point – models of pterosaurs with forward-facing pteroids were not only adept at gliding, but were agile flyers in spite of their size. ‘This high-lift capability would have significantly reduced the minimum flight speed, allowing even the largest forms to take off without difficulty,’ Wilkinson says. ‘It would have enabled them to glide very slowly and may have been instrumental in the evolution of large size by the pterosaurs.’

Resting in the grass at the test site near Cambridge, the robot-model’s wings ripple in the wind. In flight, the flexible membrane, while much stiffer than the real thing, allows for a smooth takeoff and landing. But the model has been troubled by other mechanical problems. ‘Unlike an aircraft, which is stabilised by the tail wing at the back, the model is stabilised by its head, which means it can start spinning around. That’s the most problematic bit as far as we’re concerned,’ Wilkinson says. ‘We’ve had to take it flying without the head so far.’ When it flies with its head attached, Wilkinson will finally have proved his point.

So what’s next for the zoologist – perhaps a full-size Tyrannosaurus rex? ‘No,’ he tells me: We’re desperate to build really big pterosaurs. I’m talking creatures with even greater wingspans, weighing a quarter of a ton. But,’ he adds, just as one begins to fear for the safety and stress levels of pilots landing nearby at Cambridge City Airport, ‘it’s more likely we’ll start off with one of the smaller, flapping pterosaurs.’ This is certainly more reassuring. Let’s hope he is content to leave it at that.

Questions 27 – 32
Complete the summary using the list of words, A-L, below.
Write the correct letter, A-L, in boxes 27-32 on your answer sheet.

Pterosaurs are believed to have existed until the end of the Cretaceous period. They are classed as 27……… which were capable of flight, although, unlike modern species, they had some 28 …….., which is evidence of their having had warm blood. There are two theories as to how they moved on land: perhaps with aII their feet or by using their 29 …….. only Another mystery has concerned the ability of the pterosaur to fly despite its immense 30 …….., and the fact that the bones making up the wing did not have great 31……..Thanks to reptile fossils found in Brazil, we now know that the subspecies known as anhanguera had wings that were 12 metres across and that it mainly survived on 32 ……..

A front                  B feet         C dinosaurs           D reptiles         E flexibility         F hind legs
G amphibians       H birds      I strength               J weight            K tail                  L hair

Questions 33 – 36
Do the following statements agree with the claims of the writer in Reading Passage 3? In boxes 33-36 on your answer sheet, write
YES if the statement agrees with the claims of the writer
NO if the statement contradicts the claims of the writer
NOT GIVEN if it is impossible to say what the writer thinks about this

33 It is rare to find a fossil of a pterosaur that clearly shows its skeleton.
34 The reason for building the model was to prove pterosaurs flew for long distances.
35 It is possible that pterosaur species achieved their wing size as a result of the pteroid.
36 Wilkinson has made several unsuccessful replicas of the pterosaur’s head.

Questions 37 – 40
Choose the correct letter, A, B, C or D.
Write the correct letter in boxes 37-40 on your answer sheet.

37 What was Professor Wilkinson’s main problem, according to the third paragraph?
A Early amphibians had a more complex structure than pterosaurs.
B Pterosaur wings could easily be damaged while on the ground.
C Flying squirrels and bats were better adapted to flying than pterosaurs.
D Large pterosaurs were not able to take off like other flying animals.

38 What did Professor Wilkinson discover about a bone in pterosaurs called a pteroid?
A It was in an unexpected position.
B It existed only in large species of pterosaurs.
C It allowed pterosaurs to glide rather than fly.
D It increased the speed pterosaurs could reach in the air.

39 According to the writer, the main problem with the remote-controlled ‘pterosaur’ is that
A it has been unable to leave the ground so far.
B it cannot be controlled when its head is attached.
C its wing material is not flexible enough.
D the force of the wind may affect its test results.

40 What does ‘it’ in the last sentence refer to?
A the information the tests have revealed
B Wilkinson’s sense of achievement
C Wilkinson’s desire to build models
D the comparison between types of models