TPO47-Pterosaurs were an ancient group of winged reptiles that lived alongside the dinosaurs. Many pterosaurs were very large, some as large as a giraffe and with a wingspan of over 12 meters. Paleontologists have long wondered whether large pterosaurs were capable of powered flight (flying by flapping their wings) or whether they were able only to glide. Several arguments have been made against powered flight.
Doubters point out that since modern reptiles are cold-blooded, ancient reptiles such as pterosaurs were probably cold-blooded as well. Cold-blooded animals typically have a slow metabolism and are unable to produce a lot of energy. Powered flight is an activity requiring a lot of energy, which is why all modern vertebrates that fly are warm-blooded, not cold-blooded. It seemed unlikely that pterosaurs would have been able to generate the energy needed to fly.
Second, there is a limit to the weight of animals that can be kept airborne by powered flight. Pterosaurs that were as large as a giraffe were probably so heavy that they would not have been able to flap their wings fast enough to stay aloft for any length of time.
Third, all animals with powered flight are able to take off from the ground. For example, birds take off by jumping from their legs or running to gain speed and then jumping. But these methods would not have worked for large pterosaurs. Large pterosaurs would have needed big, powerful muscles in their back legs to launch themselves into the air, and we know from fossilized bones that their back leg muscles were too small and weak to allow the pterosaurs to run fast enough or jump high enough to launch themselves into the air.
The writer and the professor have a debate on whether pterosaurs can achieve powered flight. The writer proposes that they are not capable of powered flight because they are cold blooded, heavy and have small muscle to take off. The professor, however, contradicts this opinion due to the following reasons.
First, the writer holds that pteroasurs, similar to most modern reptiles, are cold-blooded, and thus impossible to produce energy. On the contrary, the professor thinks that this opintion doesn't hold water because pteroasurs may have some way to keep warm. In detail, some reptiles have some special hairs to keep the body warm. As a result, if pteroasurs are the same kind of animals, they are also able to generate the energy to fly like the warm-blooded birds.
Second, as opposed to the writer's statement that pterosaurs are too heavy to flap wings and fly, the professor contends that pterosaurs have some special features which can make them possible to flap their wings fast enough. In accordance with the professor, pterosaurs' bones are hollow, and thus these bones are lightwight than what it looks like. Therefore, the weight of pterosaurs's weights are low enough to enable them flapping wings and fly.
Third, the writer believes that pterosaurs' leg muscles are not strong enough so it is arduous for them to run in a high speed and take off. The professor admits that birds indeed need strong leg to jump and take off. But the professor argues that pterosaurs have four legs to utilize during take off. To be more specific, unlike birds who are only capable of using two legs to run on the ground, pterosaurs have the competence to use all their four legs during taking off. As a result, it is feasible for them to run considerably fast and jump high without effort.
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No. of Sentences: 15 12
No. of Words: 306 250
No. of Characters: 1447 1200
No. of Different Words: 156 150
Fourth Root of Number of Words: 4.182 4.2
Average Word Length: 4.729 4.6
Word Length SD: 2.397 2.4
No. of Words greater than 5 chars: 99 80
No. of Words greater than 6 chars: 66 60
No. of Words greater than 7 chars: 43 40
No. of Words greater than 8 chars: 29 20
Use of Passive Voice (%): 0 0
Avg. Sentence Length: 20.4 21.0
Sentence Length SD: 7.2 7.5
Use of Discourse Markers (%): 0.667 0.12
Sentence-Text Coherence: 0.365 0.35
Sentence-Para Coherence: 0.587 0.50
Sentence-Sentence Coherence: 0.178 0.07
Number of Paragraphs: 4 4