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 disagrees with the notion in the text about three hypotheses that explain how agnostides may have lived. She brings several reasons to support her idea.
First, the speaker mentions that all of the free-swimming predator had eye but agonstids were blind. As a result, agnostids were not able to prey. Hence, agnostides were not predators. However, the reading specifies that agnostids were free-swimming predator because like the arthropods they were strong swimmers and active predators.
Second, the lecturer claims that seafloor Dwellers do not have enough ability in order to move fast and go to other places while agnostids were able to spread in large distances very fast. Consequently, agnostides were not the seafloor Dwellers. In contrast, the article states that agnostids have lived on the seafloor and were able to feed on bacteria.
Finally, the instructor hints that the populations of parasites is not very large. However, agnostides populations were very large. Therefore, the agnostides were not parasites. On the other hand, according to the reading, agnostides were parasites and they lived and feeding on larger organisms such as primitive fish or larger arthropods.
To sum up, according to the professor, three theories that mentioned in the passage regarding how agnostids may have lived are totally wrong. As a matter of fact, the professor thinks that agnostides were not free-swimming predators, seafloor Dwellers and they were not parasites.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2019-09-04 | mike10m1 | 73 | view |
| 2018-08-31 | umangranjitshrestha | 65 | view |
| 2019-05-23 | vahidvh | 80 | view |
| 2019-09-04 | mike10m1 | 70 | view |
| 2018-08-31 | umangranjitshrestha | 65 | view |
- A huge marine mammal known as Steller’s sea cow once lived in the waters around Bering Island off the coast of Siberia. It was described in 1741 by Georg W. Steller, a naturalist who was among the first Europeans to see one. In 1768 the animal became ex 80
- People should buy goods from their internal products 63
- make decision quickly or not 66
- Strict teacher or easy going teacher 80
- Learn facts on the class room or on academic trip 70
Grammar and spelling errors:
Line 3, column 34, Rule ID: ALL_OF_THE[1]
Message: Simply use 'all the'.
Suggestion: all the
...ea. First, the speaker mentions that all of the free-swimming predator had eye but agon...
^^^^^^^^^^
Transition Words or Phrases used:
but, consequently, finally, first, hence, however, if, may, regarding, second, so, therefore, well, while, in contrast, such as, as a matter of fact, as a result, to sum up, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 2.0 5.04856512141 40% => OK
Conjunction : 8.0 7.30242825607 110% => OK
Relative clauses : 8.0 12.0772626932 66% => More relative clauses wanted.
Pronoun: 13.0 22.412803532 58% => OK
Preposition: 26.0 30.3222958057 86% => OK
Nominalization: 0.0 5.01324503311 0% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1266.0 1373.03311258 92% => OK
No of words: 231.0 270.72406181 85% => More content wanted.
Chars per words: 5.48051948052 5.08290768461 108% => OK
Fourth root words length: 3.89854898053 4.04702891845 96% => OK
Word Length SD: 2.8173537994 2.5805825403 109% => OK
Unique words: 121.0 145.348785872 83% => More unique words wanted.
Unique words percentage: 0.52380952381 0.540411800872 97% => OK
syllable_count: 387.0 419.366225166 92% => OK
avg_syllables_per_word: 1.7 1.55342163355 109% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 3.25607064018 31% => OK
Interrogative: 0.0 0.116997792494 0% => OK
Article: 8.0 8.23620309051 97% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 5.0 2.5761589404 194% => OK
Performance on sentences:
How many sentences: 15.0 13.0662251656 115% => OK
Sentence length: 15.0 21.2450331126 71% => The Avg. Sentence Length is relatively short.
Sentence length SD: 48.4476349612 49.2860985944 98% => OK
Chars per sentence: 84.4 110.228320801 77% => OK
Words per sentence: 15.4 21.698381199 71% => OK
Discourse Markers: 12.7333333333 7.06452816374 180% => OK
Paragraphs: 5.0 4.09492273731 122% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 6.0 4.27373068433 140% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.278066361374 0.272083759551 102% => OK
Sentence topic coherence: 0.130073476099 0.0996497079465 131% => OK
Sentence topic coherence SD: 0.0782495881517 0.0662205650399 118% => OK
Paragraph topic coherence: 0.163133487987 0.162205337803 101% => OK
Paragraph topic coherence SD: 0.0523344501796 0.0443174109184 118% => OK
Essay readability:
automated_readability_index: 12.1 13.3589403974 91% => Automated_readability_index is low.
flesch_reading_ease: 47.79 53.8541721854 89% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 10.3 11.0289183223 93% => OK
coleman_liau_index: 14.21 12.2367328918 116% => OK
dale_chall_readability_score: 8.14 8.42419426049 97% => OK
difficult_words: 55.0 63.6247240618 86% => OK
linsear_write_formula: 6.5 10.7273730684 61% => OK
gunning_fog: 8.0 10.498013245 76% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
---------------------
Rates: 81.6666666667 out of 100
Scores by essay e-grader: 24.5 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.