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.
The reading passage contends that T.rex's arms were well-adapted for slashing attacks on its prey and provides several evidences that seem to uphold the claim. However, the lecture disapproves the reading passage by mentioning that it still remains unlikely that slashing would have been the primary purpose for such arms. The points made in the lecture will be elaborated in more detail below.
First of all, the lecture counterpoints the reading passage, which claims that there is existing evidence regarding the structure of the arms, by commenting that slashing would not have been a neccessity for survival. Several fossils show that the arms had initially been broken and have been put together after a long time has passed. T.rex must not have had enough power to perform slashing because it would have been vital to them and could have resulted in death.
Secondly, while the reading passage asserts that the claws of T.rex show an unusual feature which is well-suited to slashing, the lecture disapproves this point by claiming that this is highly irrelevant. The teeth were up to 30 centimeters long and have been proven to have the strongest biting pressure known in the world. Slashing the prey would not have made a significant difference compared to biting a prey because teeth would have caused most of the damage.
Last but not least, the reading passage contends that the length of the arms presents efficiency when slashing a prey. However, the lecture counterpoints this evidence by mentioning that this may be true only for young T.rex. Young T.rex had a relatively longer arm in proportion to the body compared to adult T.rex which would have helped them in catching prey. However, adult T.rex had jaws that were much more powerful than slashing, which led them to having child sized arm because they were no longer needed.
Transition Words or Phrases used:
but, first, however, if, may, regarding, second, secondly, still, well, while, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 10.0 5.04856512141 198% => OK
Conjunction : 5.0 7.30242825607 68% => OK
Relative clauses : 17.0 12.0772626932 141% => OK
Pronoun: 23.0 22.412803532 103% => OK
Preposition: 31.0 30.3222958057 102% => OK
Nominalization: 4.0 5.01324503311 80% => OK
Performance on vocabulary words:
No of characters: 1541.0 1373.03311258 112% => OK
No of words: 307.0 270.72406181 113% => OK
Chars per words: 5.01954397394 5.08290768461 99% => OK
Fourth root words length: 4.18585898806 4.04702891845 103% => OK
Word Length SD: 2.44682869937 2.5805825403 95% => OK
Unique words: 152.0 145.348785872 105% => OK
Unique words percentage: 0.495114006515 0.540411800872 92% => More unique words wanted or less content wanted.
syllable_count: 459.0 419.366225166 109% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 0.0 3.25607064018 0% => OK
Article: 8.0 8.23620309051 97% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => 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: 23.0 21.2450331126 108% => OK
Sentence length SD: 37.6162497934 49.2860985944 76% => OK
Chars per sentence: 118.538461538 110.228320801 108% => OK
Words per sentence: 23.6153846154 21.698381199 109% => OK
Discourse Markers: 7.0 7.06452816374 99% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 8.0 4.45695364238 179% => OK
Sentences with neutral sentiment: 2.0 4.27373068433 47% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.199150946282 0.272083759551 73% => OK
Sentence topic coherence: 0.0811740361449 0.0996497079465 81% => OK
Sentence topic coherence SD: 0.0419282402765 0.0662205650399 63% => OK
Paragraph topic coherence: 0.134664655345 0.162205337803 83% => OK
Paragraph topic coherence SD: 0.0433129708109 0.0443174109184 98% => OK
Essay readability:
automated_readability_index: 14.0 13.3589403974 105% => OK
flesch_reading_ease: 56.59 53.8541721854 105% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 11.1 11.0289183223 101% => OK
coleman_liau_index: 12.13 12.2367328918 99% => OK
dale_chall_readability_score: 8.02 8.42419426049 95% => OK
difficult_words: 63.0 63.6247240618 99% => OK
linsear_write_formula: 11.0 10.7273730684 103% => OK
gunning_fog: 11.2 10.498013245 107% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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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.