TPO 47

The article states that Pterosaurs were incapable of powered flight, which is flying by flapping their wings, and provides three reasons of support. However, the professor explains that recent researches have proved that pterosaurs were in-fact capable of powered flight and refutes each of the author's reasons.

First, the reading states that powered flight requires lots of energy and cold-blooded pterosaurs were not able to produce this energy. The professor refutes this point by mentioning that some fossils have been found that have dense coverings like fur. She elaborates on this by mentioning that this covering is typical for warm-blooded animals because they want to keep their body temperatures high. She explains that pterosaurs metabolism were probably like this warm-blooded animals, so they could have been able to produce the needed energy.

Second, the author posits that pterosaurs were probably heavy so they were incapable of powered flight. However, the professor explains that their anatomical features prove that they were actually light for their size. She says that they had hollow bones, which made it possible for their big body frame to have a low weight.

Third, the reading claims that because of their weak back leg muscles, pterosaurs were not able too take off before powered flight. The professor challenges this point by explaining that take off would have been a problem for them if they were just like birds. She explains that birds and pterosaurs have some differences. She states that birds use just two legs in take-off but pterosaurs use all their four legs on the ground, so they use all those four legs to push them for take off. She says that this would have allowed pterosaurs to run fast and launch easily.