tpo47 integrated writing

Recent research has revealed that pterosaurs may, in fact, have been capable of powered flight.

The professor in the listening part holds the arguments in the reading are not convincing.

 

First, the issue of pterosaur metabolism. Some recently discovered pterosaur fossils indicate that pterosaurs had a dense, hairlike covering, somewhat similar to fur. Hair or fur covering is typical of warm-blooded animals because those animals need to maintain a high body temperature when external conditions are cold. So, if the metabolism of pterosaurs was more like that of warm-blooded animals, and so faster than the reading suggests, then it would have supplied them with the energy needed for powered flight.

First of all, fossils show that pterosaurs have dense hairs functioning like the fur in warm-blooded animals to keep them warm in cold weather. And this also indicates that pterosaurs have faster metabolism which would generates enough energy to let them fly.

 

Second, the idea that large pterosaurs couldn’t use powered flight because they were too heavy. We now know that pterosaurs had anatomical features that made them unusually light for their size. For example, the bones of pterosaurs were hollow instead of solid. Hollow, lightweight bones would have kept the pterosaurs’ weight low despite their large body frames. The pterosaurs’ weight was probably low enough to allow them to keep themselves airborne by flapping their wings.

Secondly, the bones of pterosaurs are hollow. This evidence means pterosaurs are much light than it supposed to be. So, the pterosaurs are very likely to hold the light weight just by flapping their wings.

 

Third, takeoff would indeed be a problem for pterosaurs—if they took off the way birds do. But there are important differences between birds and pterosaurs. Birds only use their hind limbs—their legs—for walking on the ground, so they only have two limbs to push off from when they launch. But pterosaurs walked on all four limbs while on the ground.

There are modern flying animals that walk on all four limbs—bats, for example—and they use all four limbs to push off the ground, not just the back ones. Studies indicate that even the largest pterosaurs would’ve had no trouble using all four limbs to run fast enough or jump high enough to launch themselves into the air.

 

Thirdly, pterosaurs can use their four limbs to take off the ground. It is true for birds to take off by using their back legs. However, there are other animals like the bats which leave the ground using all of their four limbs. So, even though the pterosaurs back leg are not strong enough for them to take off from ground, they can actually begin their powered flight by used all of their limbs. Additionally, pterosaurs used four limbs to run on the ground. It is very reasonable they can run fast enough and then use all of their limbs to jump.

 

So, pterosaurs were really capable for powered flight.