Reading Passage
Among the intriguing mysteries that the dinosaurs have left for us, one of the most persistent is what the arms of Tyrannosaurus Rex (T.rex) were used for. A recent presentation to the American Geological Society presented evidence to support the idea that the arms were well-adapted for slashing attacks on T. rex's prey.
Firstly there is evidence related to the structure of the arms. The arms of T. rex appeared to be so tiny and weak compared to the rest of its body that early researchers dismissed them as being virtually useless. But recent analysis of marks on the fossilized bones of T. rex arms show that they were connected by significant amounts of muscle tissue: enough to lift or push nearly 400 kilograms. They would have had plenty of power to slash.
Secondly, the claws of T. rex show an unusual feature which would have made them very well-suited to slashing. Each arm has only two claws, as opposed to the three claws that are normal on smaller carnivorous dinosaurs. The reduced number of claws means that the power of the arm would be focused onto just two points, resulting in deeper cuts. And the curved claws themselves were 6 to 10 centimeters long, similar in size to the teeth of T. rex.
Thirdly, the length of the arms makes sense in terms of efficiency. The arms could have provided T. rex with the means to slash at prey held in its jaws. With the jaws holding the prey close, the arms would have been able to tear gashes over a meter long and several centimeters deep in just a few seconds. Longer or heavier arms might have done the job better, but they would have weighed more and cost T. rex too much energy to carry around.
Narrator: Now listen to part of a lecture on the topic you just read about.
Professor
Now, it may be that T. rex did slash at its prey with it's arms, but it remains unlikely that slashing prey was the primary purpose of those limbs.
First, sure, the arms were stronger than earlier researchers thought. But even though the arms could slash, slashing prey with its arms was probably not necessary to the survival of a T. rex. This is apparent because there are a large number of fossil T. rex arms that show fractures where the bone must have been broken while the T. rex was alive and then had time to heal. If slashing with its arms were vital to T. rex for catching prey, then those broken arm bones should have resulted in the death of those T. rex.
Secondly, the power of the two claws of the Tyrannosaur as slashing weapons would have been irrelevant in light of how much weaker they were than the jaws. T. rex had teeth that were up to 30 centimeters long, and it had the strongest bite pressure of any land animal known to man. Next to that kind of power, slashing with two claws would not have made much difference. Anything caught in the jaws would have been wounded far more severely by the teeth and the crushing bite force.
Finally, there is some evidence that the arms would only have been efficient slashing tools for young T. rexes but not for adult T.rexes. The arms of a T. rex may have been longer, in proportion to its body when a T.rex was young. Longer arms would have helped a younger T. rex to catch and kill prey. But the arms wouldn't have been needed when the T.rex had its adult jaws. So T.rex arms could be small because an adult T. rex was essentially still carrying, well, child-sized arms that it no longer needed.
The article and lecture discusses the topic about the idea that the arms of Tyrannosaurus Rex were well adapted for slashing attack on preys. The author of the passage supports the idea and provide three reasons to give evidence that the arms were sufficient for slashing the prey. However the lecturer disagree with the opinion and suggest that the T.rex's jaws were more developed to catch their prey and arms didn't provide much additional help.
According to the author, T.rex's arm have large amount of muscle tissue which were strong enough to slash the prey. However, the lecturer suggest that the fossil evidence also shows that the bones of the T.rex were broken when they lived. This means that if arms are only way to slash the prey, the animal would have died in some amount of time due to unavaibility of the food. However, it was not the case and the lecturer conclude's that the T.rex used their teeth to kill the prey.
Secondly, the author suggest that the structure and design of their arms of having two claws was quite different from the usual carnivorous dinosaurs. The two claws provide extra pressure and lead to deeper cut in the prey. The lecturer disagree, because the T.rex have a strong jaw and their teeth were about thirty centimeters long. With having such a large teeth, having two claws won't have a greater impact on the killing the prey as the jaws alone were sufficient to do the task.
Lastly, the author suggest that the smaller arms were benificial to T.rex as they could slash the prey with less energy consumed and hence it proves to be more effecitive. The lecturer agrees that it would be the case for the young T.rex as their jaws might not be fully devlop, but for the elder T.rex the arm lenghth doesn't matter as the fully grown jaws will able to slash the prey harder.
Grammar and spelling errors:
Line 1, column 283, Rule ID: SENT_START_CONJUNCTIVE_LINKING_ADVERB_COMMA[1]
Message: Did you forget a comma after a conjunctive/linking adverb?
Suggestion: However,
... were sufficient for slashing the prey. However the lecturer disagree with the opinion ...
^^^^^^^
Line 1, column 412, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: didn't
... developed to catch their prey and arms didnt provide much additional help. Accord...
^^^^^
Line 5, column 361, Rule ID: A_PLURAL[2]
Message: Don't use indefinite articles with plural words. Did you mean 'tooth'?
Suggestion: tooth
...timeters long. With having such a large teeth, having two claws wont have a greater i...
^^^^^
Line 7, column 320, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: doesn't
...but for the elder T.rex the arm lenghth doesnt matter as the fully grown jaws will abl...
^^^^^^
Transition Words or Phrases used:
also, but, hence, however, if, lastly, second, secondly, so, well
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 14.0 10.4613686534 134% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 10.0 7.30242825607 137% => OK
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 21.0 22.412803532 94% => OK
Preposition: 30.0 30.3222958057 99% => OK
Nominalization: 2.0 5.01324503311 40% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1498.0 1373.03311258 109% => OK
No of words: 322.0 270.72406181 119% => OK
Chars per words: 4.65217391304 5.08290768461 92% => OK
Fourth root words length: 4.23607819155 4.04702891845 105% => OK
Word Length SD: 2.1016471263 2.5805825403 81% => OK
Unique words: 154.0 145.348785872 106% => OK
Unique words percentage: 0.478260869565 0.540411800872 88% => More unique words wanted or less content wanted.
syllable_count: 448.2 419.366225166 107% => OK
avg_syllables_per_word: 1.4 1.55342163355 90% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 24.0 21.2450331126 113% => OK
Sentence length SD: 34.8898520368 49.2860985944 71% => OK
Chars per sentence: 115.230769231 110.228320801 105% => OK
Words per sentence: 24.7692307692 21.698381199 114% => OK
Discourse Markers: 5.0 7.06452816374 71% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 8.0 4.45695364238 179% => OK
Sentences with neutral sentiment: 1.0 4.27373068433 23% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.222325422584 0.272083759551 82% => OK
Sentence topic coherence: 0.095380527882 0.0996497079465 96% => OK
Sentence topic coherence SD: 0.0503849902693 0.0662205650399 76% => OK
Paragraph topic coherence: 0.153767796245 0.162205337803 95% => OK
Paragraph topic coherence SD: 0.0430264258828 0.0443174109184 97% => OK
Essay readability:
automated_readability_index: 12.9 13.3589403974 97% => OK
flesch_reading_ease: 64.04 53.8541721854 119% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 10.3 11.0289183223 93% => OK
coleman_liau_index: 9.99 12.2367328918 82% => OK
dale_chall_readability_score: 7.38 8.42419426049 88% => OK
difficult_words: 52.0 63.6247240618 82% => More difficult words wanted.
linsear_write_formula: 10.5 10.7273730684 98% => OK
gunning_fog: 11.6 10.498013245 110% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Write the essay in 20 minutes.
Rates: 73.3333333333 out of 100
Scores by essay e-grader: 22.0 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.