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 cap

Essay topics:

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.

In the given set of materials, there is some discrepancy between the views of the author and the lecturer. With three cogent explanations, the lecturer refutes the author's opinion that pterosaurs were incapable of powered flight. 



First, the lecturer states that there are signs suggesting that pterosaurs are warm-blooded, rather than cold-blooded. The recently discovered fossil of pterosaurs indicates the dense fur covering, which is a characteristic of warm-blooded animals, since these furs are crucial for warm-blooded to restore heat during cold weather. This finding strongly opposes the writer's claim that pterosaurs were cold-blooded and that they were unable to produce energy to fly. Instead, pterosaurs may have been able to generate the energy needed for powered flight.



Second, the lecturer indicates dissent over the lecturer's idea that pterosaurs were too heavy to be kept airborne by powered flight. Indeed, there is a weight limit to airborne animals, but the huge frame of pterosaurs does not necessarily prove its heavy weight. In fact, findings suggest that the bones of pterosaurs were hollow, which means that these bones were lighter than scientists imagined. This shows that the weight of pterosaurs might have been low enough for them to be airborne. 



Third, the lecturer goes on to expound that the author's final point on pterosaurs' inability to take off is flawed. She distinguishes the take-off of birds from that of pterosaurs. Birds use two limbs to take off, while pterosaurs could take advantage of their four limbs to push off the ground. Therefore, that the back leg muscles were too weak does not mean that pterosaurs cannot take off from the ground.

With the three findings covered in her speech, the lecturer has full reasons to believe that probably pterosaurs could fly.

Votes
Average: 8 (2 votes)
Essay Categories
Essays by the user:

Comments

Grammar and spelling errors:
Line 1, column 236, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...osaurs were incapable of powered flight. 

 First, the lecturer states that there ar...
^^^^^^^^^
Line 5, column 561, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...te the energy needed for powered flight.

 Second, the lecturer indicates dissent o...
^^^^^^^^
Line 9, column 257, Rule ID: HEAVY_WEIGHT[1]
Message: Did you mean 'heavyweight'?
Suggestion: heavyweight
...erosaurs does not necessarily prove its heavy weight. In fact, findings suggest that the bon...
^^^^^^^^^^^^
Line 9, column 499, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...been low enough for them to be airborne. 

 Third, the lecturer goes on to expound t...
^^^^^^^^^

Transition Words or Phrases used:
but, first, may, second, so, therefore, third, while, in fact

Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments

Performance on Part of Speech:
To be verbs : 18.0 10.4613686534 172% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 3.0 7.30242825607 41% => More conjunction wanted.
Relative clauses : 16.0 12.0772626932 132% => OK
Pronoun: 24.0 22.412803532 107% => OK
Preposition: 42.0 30.3222958057 139% => OK
Nominalization: 0.0 5.01324503311 0% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.

Performance on vocabulary words:
No of characters: 1589.0 1373.03311258 116% => OK
No of words: 301.0 270.72406181 111% => OK
Chars per words: 5.27906976744 5.08290768461 104% => OK
Fourth root words length: 4.16525528304 4.04702891845 103% => OK
Word Length SD: 2.66651811744 2.5805825403 103% => OK
Unique words: 161.0 145.348785872 111% => OK
Unique words percentage: 0.53488372093 0.540411800872 99% => OK
syllable_count: 463.5 419.366225166 111% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK

A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 6.0 8.23620309051 73% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 5.0 2.5761589404 194% => OK

Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 25.0 21.2450331126 118% => OK
Sentence length SD: 60.2225040994 49.2860985944 122% => OK
Chars per sentence: 132.416666667 110.228320801 120% => OK
Words per sentence: 25.0833333333 21.698381199 116% => OK
Discourse Markers: 5.08333333333 7.06452816374 72% => OK
Paragraphs: 5.0 4.09492273731 122% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 5.0 4.33554083885 115% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 4.0 4.27373068433 94% => OK
What are sentences with positive/Negative/neutral sentiment?

Coherence and Cohesion:
Essay topic to essay body coherence: 0.252222977359 0.272083759551 93% => OK
Sentence topic coherence: 0.0983330700486 0.0996497079465 99% => OK
Sentence topic coherence SD: 0.0605974367763 0.0662205650399 92% => OK
Paragraph topic coherence: 0.14080291859 0.162205337803 87% => OK
Paragraph topic coherence SD: 0.0463991407637 0.0443174109184 105% => OK

Essay readability:
automated_readability_index: 16.0 13.3589403974 120% => OK
flesch_reading_ease: 54.56 53.8541721854 101% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 11.9 11.0289183223 108% => OK
coleman_liau_index: 13.64 12.2367328918 111% => OK
dale_chall_readability_score: 8.23 8.42419426049 98% => OK
difficult_words: 64.0 63.6247240618 101% => OK
linsear_write_formula: 14.0 10.7273730684 131% => OK
gunning_fog: 12.0 10.498013245 114% => OK
text_standard: 14.0 11.2008830022 125% => OK
What are above readability scores?

---------------------

Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
---------------------
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.