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 article and the lecture are both about pterosaurs' powered flight. The article made three points about pterosaurs to disprove that they were capable of powered flight, while the lecturer disagrees with those opinions.
First of all, the article mentions that pterosaurs were probably cold-blooded, so they did not have sufficient energy produced by metabolism to let them perform powered flight. However, the lecturer disputes the idea by introducing some potential evidence. Scientists found that pterosaurs' fossils were covered by dense hairs, and that illustrates that they may probably be warm-blooded. Since those feather-like hairs may possibly be used to keep their body warm to save energy. Therefore, the lecturer believes that pterosaurs may have enough energy for powered flight.
Secondly, the article suggests that pterosaurs are way too heavy for powered flight. Nevertheless, the lecturer does not agree with that. She believes that pterosaurs may have some special structures of their body that reduce their weight. For example, their bones may be hollow instead of being solid. The special structures could keep their weight unusually low and allow them to perform powered flight.
Finally, the article indicates that pterosaurs had problems taking off from the ground due to their small and weak back legs which are usually used for birds to take off. However, the lecturer has an opposite perspective. She says that pterosaurs might not use the same way as birds to take off from the land. Birds use two legs to take off, while it is possible for pterosaurs to take off with all of their four limbs. Thus, they would have the ability to jump high enough or run fast enough to take off and perform powered-flight.
Grammar and spelling errors:
Line 3, column 389, Rule ID: SENTENCE_FRAGMENT[1]
Message: “Since” at the beginning of a sentence requires a 2nd clause. Maybe a comma, question or exclamation mark is missing, or the sentence is incomplete and should be joined with the following sentence.
...that they may probably be warm-blooded. Since those feather-like hairs may possibly b...
^^^^^
Line 3, column 420, Rule ID: MIGHT_PERHAPS[1]
Message: Use simply 'may', 'possibly'.
Suggestion: may; possibly
...blooded. Since those feather-like hairs may possibly be used to keep their body warm to save...
^^^^^^^^^^^^
Line 3, column 420, Rule ID: MAY_COULD_POSSIBLY[1]
Message: Use simply 'may'.
Suggestion: may
...blooded. Since those feather-like hairs may possibly be used to keep their body warm to save...
^^^^^^^^^^^^
Transition Words or Phrases used:
finally, first, however, may, nevertheless, second, secondly, so, therefore, thus, while, for example, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 8.0 5.04856512141 158% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 30.0 22.412803532 134% => Less pronouns wanted
Preposition: 36.0 30.3222958057 119% => 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: 1465.0 1373.03311258 107% => OK
No of words: 281.0 270.72406181 104% => OK
Chars per words: 5.21352313167 5.08290768461 103% => OK
Fourth root words length: 4.09427095027 4.04702891845 101% => OK
Word Length SD: 2.57034120649 2.5805825403 100% => OK
Unique words: 146.0 145.348785872 100% => OK
Unique words percentage: 0.519572953737 0.540411800872 96% => OK
syllable_count: 439.2 419.366225166 105% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 10.0 8.23620309051 121% => OK
Subordination: 3.0 1.25165562914 240% => Less adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
Performance on sentences:
How many sentences: 17.0 13.0662251656 130% => OK
Sentence length: 16.0 21.2450331126 75% => The Avg. Sentence Length is relatively short.
Sentence length SD: 36.404399141 49.2860985944 74% => OK
Chars per sentence: 86.1764705882 110.228320801 78% => OK
Words per sentence: 16.5294117647 21.698381199 76% => OK
Discourse Markers: 6.76470588235 7.06452816374 96% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 3.0 4.19205298013 72% => OK
Sentences with positive sentiment : 7.0 4.33554083885 161% => OK
Sentences with negative sentiment : 4.0 4.45695364238 90% => OK
Sentences with neutral sentiment: 6.0 4.27373068433 140% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.160969550112 0.272083759551 59% => OK
Sentence topic coherence: 0.0620087592323 0.0996497079465 62% => OK
Sentence topic coherence SD: 0.047270757872 0.0662205650399 71% => OK
Paragraph topic coherence: 0.112360744701 0.162205337803 69% => OK
Paragraph topic coherence SD: 0.036971277547 0.0443174109184 83% => OK
Essay readability:
automated_readability_index: 11.4 13.3589403974 85% => Automated_readability_index is low.
flesch_reading_ease: 55.24 53.8541721854 103% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.5 11.0289183223 86% => OK
coleman_liau_index: 12.64 12.2367328918 103% => OK
dale_chall_readability_score: 7.24 8.42419426049 86% => OK
difficult_words: 50.0 63.6247240618 79% => More difficult words wanted.
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 8.4 10.498013245 80% => OK
text_standard: 8.0 11.2008830022 71% => OK
What are above readability scores?
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Rates: 78.3333333333 out of 100
Scores by essay e-grader: 23.5 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.