Endotherms are animals such as modern birds and mammals that keep their body temperatures
constant. For instance, humans are endotherms and maintain an internal temperature of 37°C, no
matter whether the environment is warm or cold. Because dinosaurs were reptiles, and modern
reptiles are not endotherms, it was long assumed that dinosaurs were not endotherms. However,
dinosaurs differ in many ways from modern reptiles, and there is now considerable evidence that
dinosaurs were, in fact, endotherms.
Polar dinosaurs
One reason for believing that dinosaurs were endotherms is that dinosaur fossils have been
discovered in polar regions. Only animals that can maintain a temperature well above that of the
surrounding environment could be active in such cold climates.
Leg position and movement
There is a connection between endothermy and the position and movement of the legs. The
physiology of endothermy allows sustained physical activity, such as running. But running is efficient only if an animal’s legs are positioned underneath its body, not at the body’s side, as
they are for crocodiles and many lizards. The legs of all modern endotherms are underneath the
body, and so were the legs of dinosaurs. This strongly suggests that dinosaurs were endotherms.
Haversian canals
There is also a connection between endothermy and bone structure. The bones of endotherms
usually include structures called Haversian canals. These canals house nerves and blood vessels
that allow the living animal to grow quickly, and rapid body growth is in fact a characteristic of
endothermy. The presence of Haversian canals in bone is a strong indicator that the animal is an
endotherm, and fossilized bones of dinosaurs are usually dense with Haversian canals.
The speaker in the lecture challenge the argument in the passage that dinosaurs are not endotherms. There are explainations for each of the points mantioned in the passage.
Firstly, the passage say that fossils of dinosaurs found in polar region suggests that dinosaurs were endotherms. The lecture challange the assuptions by stating that it is possible that dinosaurs might have lived at polar regoins, but only during the warmer period. They might have migrated to the other places during the colder months. So fossils found in the polar region can not be used as evindece to prove that dinosaurs were endotherms.
Secondly, The passage says that the position and movement of legs have connection with endothermy. The lecture challages this argument by saying that position of the legs in dinosaurs were basically to support their large body strucutre. The size of crocodiles and lizard can not be compared with the size of dinosaurs. Hence, The passage's claim about the position of legs and connection to endothery is not sufficient.
Lastly, The passage says that presence of haversian canals in dinosaurs proves them to be endotherm is not correct. In the lectrue, the speaker challagnes this by saying that dinosaurs had growth rings. During cooler periods they grew less, while in warmer period they grew fast. So presence of haversian canals doesn't give enough evindece for proving dinosaurs to be endothermic.
So it can be concluded from the lecture that the proofs given in passage for endothermic nature of dinasuars are not suffcient.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2019-12-05 | mbabar | 88 | view |
| 2019-10-30 | rohanrajeev07 | 73 | view |
| 2019-04-25 | Dharapatel23 | 70 | view |
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Grammar and spelling errors:
Line 1, column 65, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...re challenge the argument in the passage that dinosaurs are not endotherms. There...
^^
Line 7, column 313, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: doesn't
...w fast. So presence of haversian canals doesnt give enough evindece for proving dinosa...
^^^^^^
Transition Words or Phrases used:
but, first, firstly, hence, lastly, second, secondly, so, while
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 : 4.0 7.30242825607 55% => More conjunction wanted.
Relative clauses : 11.0 12.0772626932 91% => OK
Pronoun: 20.0 22.412803532 89% => OK
Preposition: 37.0 30.3222958057 122% => OK
Nominalization: 10.0 5.01324503311 199% => OK
Performance on vocabulary words:
No of characters: 1312.0 1373.03311258 96% => OK
No of words: 252.0 270.72406181 93% => More content wanted.
Chars per words: 5.20634920635 5.08290768461 102% => OK
Fourth root words length: 3.98428260373 4.04702891845 98% => OK
Word Length SD: 2.64980734431 2.5805825403 103% => OK
Unique words: 121.0 145.348785872 83% => More unique words wanted.
Unique words percentage: 0.480158730159 0.540411800872 89% => More unique words wanted or less content wanted.
syllable_count: 397.8 419.366225166 95% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 3.25607064018 31% => 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: 15.0 13.0662251656 115% => OK
Sentence length: 16.0 21.2450331126 75% => The Avg. Sentence Length is relatively short.
Sentence length SD: 23.1656834324 49.2860985944 47% => The essay contains lots of sentences with the similar length. More sentence varieties wanted.
Chars per sentence: 87.4666666667 110.228320801 79% => OK
Words per sentence: 16.8 21.698381199 77% => OK
Discourse Markers: 4.2 7.06452816374 59% => More transition words/phrases wanted.
Paragraphs: 5.0 4.09492273731 122% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 2.0 4.45695364238 45% => More negative sentences wanted.
Sentences with neutral sentiment: 10.0 4.27373068433 234% => Less facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.110031721828 0.272083759551 40% => OK
Sentence topic coherence: 0.0405053882606 0.0996497079465 41% => OK
Sentence topic coherence SD: 0.036054786212 0.0662205650399 54% => OK
Paragraph topic coherence: 0.0653473105474 0.162205337803 40% => OK
Paragraph topic coherence SD: 0.0119564001341 0.0443174109184 27% => Paragraphs are similar to each other. Some content may get duplicated or it is not exactly right on the topic.
Essay readability:
automated_readability_index: 11.5 13.3589403974 86% => 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: 8.06 8.42419426049 96% => OK
difficult_words: 58.0 63.6247240618 91% => OK
linsear_write_formula: 7.5 10.7273730684 70% => OK
gunning_fog: 8.4 10.498013245 80% => OK
text_standard: 8.0 11.2008830022 71% => OK
What are above readability scores?
---------------------
Rates: 70.0 out of 100
Scores by essay e-grader: 21.0 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.