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.
Both the reading passage and the lecturer discuss whether pterosaurs were able to powered flight or just stay on the ground. The writer provides three pieces of eveidence to support pterosaurs can not fly. However, the lecturer disagrees with these statements.
First of all, the writer mentions that pterosaurs might be cold-blooded becuase modern reptiles are cold-blooded. In this case, they can not generate enough energy which use in powered flight. Still, this is very different from the lecturer's claim that the fossil indicated that pterosaurs are covered with dense hair. This feature is common among warm-blooded animals. They use hair or feather to keep their body temperature warm when the weather is cold. Therefore, pterosaurs might be warm-blooded and able to produce lots of energy to fly.
Secondly, the lecturer continues to cast doubt on the author's assertion that the size pterosaurs is too large and the weight is too heavy for them to fly in sky by flapping their wings, by examining another explanation that their bones are hollow, so their bones do not stand for a large part of their weight. Hence, their weight might be light enough to keep airborne by flapping their wings.
Third, the author also asserts that animals with powered flight need to have strong muscles on their back legs to take off from the ground. The fossil shows that pterosaur's muscle of back legs are too weak and small to support powered flight. Nevertheless, the lecturer rebuts this belief by pointing out that pterosaurs are different with birds. To be more specific, birds only use two back limbs for taking off from the ground. On the other hand, pterosaurs walk with four limb. Thus, they might run fast enough to push off themselves to the air.
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Grammar and spelling errors:
Line 5, column 55, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'authors'' or 'author's'?
Suggestion: authors'; author's
...lecturer continues to cast doubt on the authors assertion that the size pterosaurs is t...
^^^^^^^
Line 7, column 476, Rule ID: CD_NN[1]
Message: Possible agreement error. The noun 'limb' seems to be countable, so consider using: 'limbs'.
Suggestion: limbs
...e other hand, pterosaurs walk with four limb. Thus, they might run fast enough to pu...
^^^^
Transition Words or Phrases used:
also, but, first, hence, however, if, nevertheless, second, secondly, so, still, therefore, third, thus, first of all, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 10.0 12.0772626932 83% => OK
Pronoun: 26.0 22.412803532 116% => OK
Preposition: 43.0 30.3222958057 142% => OK
Nominalization: 3.0 5.01324503311 60% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1468.0 1373.03311258 107% => OK
No of words: 294.0 270.72406181 109% => OK
Chars per words: 4.99319727891 5.08290768461 98% => OK
Fourth root words length: 4.14082457966 4.04702891845 102% => OK
Word Length SD: 2.45166141897 2.5805825403 95% => OK
Unique words: 160.0 145.348785872 110% => OK
Unique words percentage: 0.544217687075 0.540411800872 101% => OK
syllable_count: 422.1 419.366225166 101% => OK
avg_syllables_per_word: 1.4 1.55342163355 90% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 6.0 3.25607064018 184% => OK
Article: 7.0 8.23620309051 85% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 17.0 13.0662251656 130% => OK
Sentence length: 17.0 21.2450331126 80% => The Avg. Sentence Length is relatively short.
Sentence length SD: 57.7125078645 49.2860985944 117% => OK
Chars per sentence: 86.3529411765 110.228320801 78% => OK
Words per sentence: 17.2941176471 21.698381199 80% => OK
Discourse Markers: 8.0 7.06452816374 113% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 5.0 4.33554083885 115% => OK
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 8.0 4.27373068433 187% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.172626971572 0.272083759551 63% => OK
Sentence topic coherence: 0.054863113849 0.0996497079465 55% => OK
Sentence topic coherence SD: 0.0494078853405 0.0662205650399 75% => OK
Paragraph topic coherence: 0.10523366964 0.162205337803 65% => OK
Paragraph topic coherence SD: 0.0337328613066 0.0443174109184 76% => OK
Essay readability:
automated_readability_index: 10.7 13.3589403974 80% => Automated_readability_index is low.
flesch_reading_ease: 71.14 53.8541721854 132% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 7.6 11.0289183223 69% => OK
coleman_liau_index: 11.37 12.2367328918 93% => OK
dale_chall_readability_score: 7.33 8.42419426049 87% => OK
difficult_words: 53.0 63.6247240618 83% => More difficult words wanted.
linsear_write_formula: 6.0 10.7273730684 56% => Linsear_write_formula is low.
gunning_fog: 8.8 10.498013245 84% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Rates: 76.6666666667 out of 100
Scores by essay e-grader: 23.0 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.