At the end of the Triassic period 200 million years ago, there was a mass-extinction event that caused the extinction of more than half of all living species. It was this extinction event that allowed dinosaurs to become the dominant species for the next 145 million years. We do not know exactly what happened that eliminated so many species in a relatively short period of time, but there are several possible explanations.One theory involves the decline of sea levels. Near the end of the Triassic period, sea levels were fluctuating. When sea levels fall, the habitats for ocean populations that live in the shallows and land species that live on the coast are destroyed. The destruction of coastal and shallow-ocean species would have had a profound effect on food chains worldwide, leading to mass extinctions.Another theory involves massive climate cooling. The end of the Triassic period was marked by widespread volcanic activity. The volcanoes released large amounts of sulfur dioxide (S02). A rise in atmospheric S02 is known to cause a lowering in global temperatures. Such climate change could have devastated many species and led to the extinctions.The third theory involves an asteroid strike. Asteroids (objects from outer space) occasionally collide with Earth. When an asteroid hits Earth’s surface, it often displaces large amounts of soil and crushed rock, leaving behind a depression, or crater. The displaced debris is thrown up into the atmosphere where it can block out sunlight for many months or even a few years. A sufficiently massive asteroid impact at the end of the Triassic period may have blocked sunlight long enough for most plants to die and many animal species to then starve.
The reading and the lecture was about the mass-extinction event that happened in the Triassic period about 200 million years ago. The reading suggests three different theories why a mass-extinction might have had happened and led to dinosaurs dominance. The lecturer, however, cast doubt on the explanations that is proposed in the reading and finds them inaccurate.
First, the reading suggests that a decline in the sea level had made food scarce and led to a mass-extinction. It says sea level was fluctuating and the species in the sea and on land were unable to cope with the change. On the contrary, the lecturer states that fluctuation in sea level is not a good explanation. She adds that coast and shore living system are gradually adaptable to change. She mentions that fluctuation takes a lot of time and happens gradually and since the mass-extinction happened quickly, it could not be a plausible explanation.
Furthermore, the reading offers the massive cooling as a reason for mass-extinction. The author believes volcanic activity released tremendous amounts of sulfur dioxide and it led to a massive cooling. The professor in contrast offered that the extinction had happened in a short period but the S02 is still present in the atmosphere too. She says S02 combines with water and comes back to earth as rain and could not have been stored in the atmosphere.
Finally, the author suggests that an asteroid strike has caused mass extinction by blocking sunlight via soil and crushed rock of a crater or depression for a long period of time. He adds that due to the lack of sunlight most plants vanished and species then starved. Conversely the lecturer say very few scientist believe on an asteroid attack. They believe in this because there is no crater found which dates back to the period of Triassic. She also adds that only one crater is found which dates back 12 million years prior to the Triassic period and that’s no evidence for a mass-extinction in that period.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2020-01-17 | nusybah | 80 | view |
| 2019-11-14 | M.S 2019 | 76 | view |
| 2019-10-24 | p0uya | 65 | view |
| 2019-10-24 | Seema Modak | 71 | view |
| 2019-10-08 | mahan vahab kashi | 80 | view |
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Grammar and spelling errors:
Line 1, column 255, Rule ID: ENGLISH_WORD_REPEAT_BEGINNING_RULE
Message: Three successive sentences begin with the same word. Reword the sentence or use a thesaurus to find a synonym.
...appened and led to dinosaurs dominance. The lecturer, however, cast doubt on the ex...
^^^
Line 13, column 165, Rule ID: PERIOD_OF_TIME[1]
Message: Use simply 'period'.
Suggestion: period
...ck of a crater or depression for a long period of time. He adds that due to the lack of sunlig...
^^^^^^^^^^^^^^
Line 13, column 269, Rule ID: SENT_START_CONJUNCTIVE_LINKING_ADVERB_COMMA[1]
Message: Did you forget a comma after a conjunctive/linking adverb?
Suggestion: Conversely,
...ants vanished and species then starved. Conversely the lecturer say very few scientist bel...
^^^^^^^^^^
Line 13, column 302, Rule ID: MANY_NN[1]
Message: Possible agreement error. The noun scientist seems to be countable; consider using: 'few scientists'.
Suggestion: few scientists
...arved. Conversely the lecturer say very few scientist believe on an asteroid attack. They bel...
^^^^^^^^^^^^^
Transition Words or Phrases used:
also, but, conversely, finally, first, furthermore, however, if, so, still, then, in contrast, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 11.0 10.4613686534 105% => OK
Auxiliary verbs: 3.0 5.04856512141 59% => OK
Conjunction : 17.0 7.30242825607 233% => Less conjunction wanted
Relative clauses : 14.0 12.0772626932 116% => OK
Pronoun: 23.0 22.412803532 103% => OK
Preposition: 36.0 30.3222958057 119% => OK
Nominalization: 14.0 5.01324503311 279% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1681.0 1373.03311258 122% => OK
No of words: 336.0 270.72406181 124% => OK
Chars per words: 5.00297619048 5.08290768461 98% => OK
Fourth root words length: 4.28139028586 4.04702891845 106% => OK
Word Length SD: 2.89674776342 2.5805825403 112% => OK
Unique words: 174.0 145.348785872 120% => OK
Unique words percentage: 0.517857142857 0.540411800872 96% => OK
syllable_count: 496.8 419.366225166 118% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 8.0 3.25607064018 246% => Less pronouns wanted as sentence beginning.
Article: 9.0 8.23620309051 109% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
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: 17.0 13.0662251656 130% => OK
Sentence length: 19.0 21.2450331126 89% => OK
Sentence length SD: 30.1789358012 49.2860985944 61% => OK
Chars per sentence: 98.8823529412 110.228320801 90% => OK
Words per sentence: 19.7647058824 21.698381199 91% => OK
Discourse Markers: 6.47058823529 7.06452816374 92% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 7.0 4.45695364238 157% => OK
Sentences with neutral sentiment: 9.0 4.27373068433 211% => Less facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.259976602967 0.272083759551 96% => OK
Sentence topic coherence: 0.0750490099428 0.0996497079465 75% => OK
Sentence topic coherence SD: 0.0935267009159 0.0662205650399 141% => OK
Paragraph topic coherence: 0.15059030081 0.162205337803 93% => OK
Paragraph topic coherence SD: 0.0797842220642 0.0443174109184 180% => OK
Essay readability:
automated_readability_index: 12.0 13.3589403974 90% => Automated_readability_index is low.
flesch_reading_ease: 60.65 53.8541721854 113% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.5 11.0289183223 86% => OK
coleman_liau_index: 11.72 12.2367328918 96% => OK
dale_chall_readability_score: 8.01 8.42419426049 95% => OK
difficult_words: 73.0 63.6247240618 115% => OK
linsear_write_formula: 11.0 10.7273730684 103% => OK
gunning_fog: 9.6 10.498013245 91% => OK
text_standard: 12.0 11.2008830022 107% => 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.