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 lecturer challenges the topic proposed in the reading that several arguments have been made against powered flight. And she thinks that recent researches show that pterosaurs probably can have powered flight.
First, the passage indicates that ancient reptiles such as pterosaurs were probably cold-blooded because modern reptiles are cold-blooded. However, the professor points out that they had dense fur-like covering which means they may warm-blooded because they have to stay in high body temperature when the external condition is cold. If they were warm-blooded and they could faster than the reading represents, they could supply a lot of energy needed for powered flight.
Second, the article mentions that there is a limit to the weight of animals that can be kept airborne by powered flight. But the lecturer argues that they could have powered flight because of their unusual body structure. Their bones were hollow instead of solid, which means their weight is low despite their large size, so they could stay aloft for any length of time.
Third, the essay supposes that all animals with powered flight are able to take off from the ground. Nevertheless, the professor supports that there are differences between birds and pterosaurs. birds only use back legs to push them to jump or run. By comparison, pterosaurs walk on four limbs, so they use all four limbs to launch themselves into the air instead of just back ones. And researches display it is not difficult for a four limbs animals to jump high enough or run fast enough to launch themselves into the air.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2019-12-06 | marii.r67 | 80 | view |
| 2019-11-13 | shirley5001 | 80 | view |
| 2019-11-13 | shirley5001 | 80 | view |
| 2019-11-03 | Seema Modak | 78 | view |
| 2019-11-03 | Seema Modak | 78 | view |
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Grammar and spelling errors:
Line 7, column 196, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: Birds
...fferences between birds and pterosaurs. birds only use back legs to push them to jump...
^^^^^
Transition Words or Phrases used:
but, first, however, if, may, nevertheless, second, so, third, such as
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 7.0 7.30242825607 96% => OK
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 28.0 22.412803532 125% => Less pronouns wanted
Preposition: 29.0 30.3222958057 96% => OK
Nominalization: 1.0 5.01324503311 20% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1328.0 1373.03311258 97% => OK
No of words: 261.0 270.72406181 96% => OK
Chars per words: 5.08812260536 5.08290768461 100% => OK
Fourth root words length: 4.0193898071 4.04702891845 99% => OK
Word Length SD: 2.48924817632 2.5805825403 96% => OK
Unique words: 148.0 145.348785872 102% => OK
Unique words percentage: 0.567049808429 0.540411800872 105% => OK
syllable_count: 389.7 419.366225166 93% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 6.0 8.23620309051 73% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 3.0 1.51434878587 198% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 20.0 21.2450331126 94% => OK
Sentence length SD: 32.974618175 49.2860985944 67% => OK
Chars per sentence: 102.153846154 110.228320801 93% => OK
Words per sentence: 20.0769230769 21.698381199 93% => OK
Discourse Markers: 5.38461538462 7.06452816374 76% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 7.0 4.27373068433 164% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.115937659897 0.272083759551 43% => OK
Sentence topic coherence: 0.041265405154 0.0996497079465 41% => OK
Sentence topic coherence SD: 0.0515267548503 0.0662205650399 78% => OK
Paragraph topic coherence: 0.0680096116009 0.162205337803 42% => OK
Paragraph topic coherence SD: 0.0266808193637 0.0443174109184 60% => OK
Essay readability:
automated_readability_index: 12.6 13.3589403974 94% => Automated_readability_index is low.
flesch_reading_ease: 59.64 53.8541721854 111% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.9 11.0289183223 90% => OK
coleman_liau_index: 12.24 12.2367328918 100% => OK
dale_chall_readability_score: 7.9 8.42419426049 94% => OK
difficult_words: 54.0 63.6247240618 85% => More difficult words wanted.
linsear_write_formula: 10.5 10.7273730684 98% => OK
gunning_fog: 10.0 10.498013245 95% => OK
text_standard: 10.0 11.2008830022 89% => OK
What are above readability scores?
---------------------
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.