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 modem 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 reading passage and the lecture are both about whether dinosaurs were endotherms or not. The author of the article believes that dinosaurs were endotherms citing three compelling reasons for this argument. However, the lecturer introduces a different point of view refuting all arguments stated in the article.
First of all, the author mentions that fossils of dinosaurs discovered in the polar region prove that they were able to live under very cold climate and only endotherms can do that. On the other hand, the lecturer illustrates another way of understanding this finding. according to the lecture, the polar region was warmer when dinosaurs lived than today allowing non-endotherms to survive there. On top of that, dinosaurs might have immigrated away from the polar region or hibernated when temperatures fell sharply.
Secondly, the author uses the position of legs in dinosaurs as evidence that they were endotherms. The lecture opposes this argument. The professor in the lecture indicates that there is a different explanation for the dinosaur legs being underneath the body and not on the side, according to the speaker, the legs underneath the body allowed the support of more weight which in turn gave dinosaurs advantage.
Finally, the article proposes that the discovery of Haversian canals inside bone fossils of dinosaurs confirms endothermy. In contrast, the lecturer points out the presence of growth rings in the bone fossils. The speaker further elaborates that growth rings are indicator of fluctuation in the growth rate with periods of rapid growth alternating with periods of slow growth and this is typical of non-endotherms
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2020-01-21 | liboooyang | 81 | view |
| 2020-01-04 | Tharwat | 83 | view |
| 2019-12-19 | savikx | 66 | view |
| 2019-12-18 | TEJAS PATIL | 80 | view |
| 2019-12-14 | fafar | 80 | view |
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Grammar and spelling errors:
Line 3, column 270, Rule ID: UPPERCASE_SENTENCE_START
Message: This sentence does not start with an uppercase letter
Suggestion: According
...ther way of understanding this finding. according to the lecture, the polar region was wa...
^^^^^^^^^
Transition Words or Phrases used:
finally, first, however, if, second, secondly, so, in contrast, first of all, on the other hand, on top of that
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 10.0 10.4613686534 96% => OK
Auxiliary verbs: 2.0 5.04856512141 40% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 12.0 12.0772626932 99% => OK
Pronoun: 15.0 22.412803532 67% => OK
Preposition: 38.0 30.3222958057 125% => OK
Nominalization: 7.0 5.01324503311 140% => OK
Performance on vocabulary words:
No of characters: 1407.0 1373.03311258 102% => OK
No of words: 262.0 270.72406181 97% => OK
Chars per words: 5.37022900763 5.08290768461 106% => OK
Fourth root words length: 4.02323427807 4.04702891845 99% => OK
Word Length SD: 2.76525861477 2.5805825403 107% => OK
Unique words: 146.0 145.348785872 100% => OK
Unique words percentage: 0.557251908397 0.540411800872 103% => OK
syllable_count: 435.6 419.366225166 104% => OK
avg_syllables_per_word: 1.7 1.55342163355 109% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 0.0 3.25607064018 0% => OK
Article: 13.0 8.23620309051 158% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 5.0 2.5761589404 194% => OK
Performance on sentences:
How many sentences: 13.0 13.0662251656 99% => OK
Sentence length: 20.0 21.2450331126 94% => OK
Sentence length SD: 59.0913443936 49.2860985944 120% => OK
Chars per sentence: 108.230769231 110.228320801 98% => OK
Words per sentence: 20.1538461538 21.698381199 93% => OK
Discourse Markers: 8.53846153846 7.06452816374 121% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 6.0 4.33554083885 138% => 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: 0.139683883419 0.272083759551 51% => OK
Sentence topic coherence: 0.0482351310537 0.0996497079465 48% => OK
Sentence topic coherence SD: 0.0426716502026 0.0662205650399 64% => OK
Paragraph topic coherence: 0.0833892920623 0.162205337803 51% => OK
Paragraph topic coherence SD: 0.0331632124133 0.0443174109184 75% => OK
Essay readability:
automated_readability_index: 13.9 13.3589403974 104% => OK
flesch_reading_ease: 42.72 53.8541721854 79% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 12.3 11.0289183223 112% => OK
coleman_liau_index: 13.87 12.2367328918 113% => OK
dale_chall_readability_score: 8.85 8.42419426049 105% => OK
difficult_words: 70.0 63.6247240618 110% => OK
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 10.0 10.498013245 95% => 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.