Agnostids were a group of marine animals that became extinct about 450 million years ago. Agnostid fossils can be found in rocks in many areas around the world. From the fossil remains, we know that agnostids were primitive arthropods-relatives of modern-day insects. However, the fossil information does not allow paleontologists to determine with certainty what agnostids ate or how they behaved. There are several different theories about how agnostids may have lived.
Free-Swimming Predators
First, the agnostids may have been free-swimming predators that hunted smaller animals. It is known that other types of primitive arthropods were strong swimmers and active predators, so it is reasonable that the agnostids may have lived that way as well And while the agnostids were small, sometimes just six millimeters long, there were plenty of smaller organisms in the ancient ocean for them to prey on.
Seafloor Dwellers
Second, they may have dwelled on the seafloor. Again, there are examples of other types of primitive arthropods living this way, so it is possible that agnostids did too. On the seafloor they would have survived by scavenging dead organisms or by grazing on bacteria.
Parasites
Third, there is the possibility that the agnostids were parasites, living on and feeding off larger organisms. One reason that this seems possible is that there are many species of modern-day arthropods that exist as parasites, such as fleas, ticks, and mites. The agnostids might have lived on primitive fish or even on other, larger arthropods.
The professor casts doubt on the three different theories explained in the passage about how agnostids feed and survive. She asserts that each theory has their own weakness.
Firstly, one hypothesis is that agnostids could freely swimm and hunt other smaller animals as other kinds of primitive animals did. However, the professor argues that agnostids are blind and do not have a good eyesight as other free-swimming predators do, which can help them chase the preys. Besides, there is no evidence that proves they have sensitive sense organ.
Secondly, according to another theory, the agnostids could survive by the means of seafloor dwellers. The professor refutes this theory and points out that the dwellers on the seafloor usually move very slow. On the contrary, it has been reported that agnostids spread wide and could own a good ability to move.
Thirdly, the author also states that agnostids live on by eating larger organisms. As the professor demonstrates, the population of the parasites animal stays within a limit, otherwise they will kill off the animals that they live on. Still, the agnostids are found out to have a large population, so they couldn't live in the way of parasites.
Grammar and spelling errors:
Line 31, column 307, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: couldn't
...out to have a large population, so they couldnt live in the way of parasites.
^^^^^^^
Transition Words or Phrases used:
also, besides, first, firstly, however, if, second, secondly, so, still, third, thirdly, well, on the contrary
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 5.0 10.4613686534 48% => More to be verbs wanted.
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 5.0 7.30242825607 68% => OK
Relative clauses : 9.0 12.0772626932 75% => More relative clauses wanted.
Pronoun: 17.0 22.412803532 76% => OK
Preposition: 21.0 30.3222958057 69% => OK
Nominalization: 3.0 5.01324503311 60% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1046.0 1373.03311258 76% => OK
No of words: 198.0 270.72406181 73% => More content wanted.
Chars per words: 5.28282828283 5.08290768461 104% => OK
Fourth root words length: 3.75116612262 4.04702891845 93% => OK
Word Length SD: 2.5449384197 2.5805825403 99% => OK
Unique words: 125.0 145.348785872 86% => More unique words wanted.
Unique words percentage: 0.631313131313 0.540411800872 117% => OK
syllable_count: 306.9 419.366225166 73% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 7.0 8.23620309051 85% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 11.0 13.0662251656 84% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 18.0 21.2450331126 85% => The Avg. Sentence Length is relatively short.
Sentence length SD: 30.6445902092 49.2860985944 62% => OK
Chars per sentence: 95.0909090909 110.228320801 86% => OK
Words per sentence: 18.0 21.698381199 83% => OK
Discourse Markers: 10.0 7.06452816374 142% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 7.0 4.45695364238 157% => 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: 0.163679730173 0.272083759551 60% => OK
Sentence topic coherence: 0.0595743960854 0.0996497079465 60% => OK
Sentence topic coherence SD: 0.0412588385826 0.0662205650399 62% => OK
Paragraph topic coherence: 0.091882489662 0.162205337803 57% => OK
Paragraph topic coherence SD: 0.0173572253502 0.0443174109184 39% => 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: 12.4 13.3589403974 93% => Automated_readability_index is low.
flesch_reading_ease: 61.67 53.8541721854 115% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 9.1 11.0289183223 83% => OK
coleman_liau_index: 13.05 12.2367328918 107% => OK
dale_chall_readability_score: 8.44 8.42419426049 100% => OK
difficult_words: 49.0 63.6247240618 77% => More difficult words wanted.
linsear_write_formula: 7.5 10.7273730684 70% => OK
gunning_fog: 9.2 10.498013245 88% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
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Rates: 70.0 out of 100
Scores by essay e-grader: 21.0 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.