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 article sates that agnostids were a group of marine animals, and paleontologists have three different theories about how agnostids may have lived. However, the lecturer explains that all three theories have their weakness, which will explore in the following essay.
First, the reading claims that agnostids may have been free-swimming predators that haunt smaller animals for living. In contrast, the lecturer refutes this point by saying that if agnostids need to swim, they need large eyes for better vision to swim in the ocean. If agnostids have tiny eyes, they can barely see when they were swimming. The fossil shows that agnostids did not have large eyes, so we can rule out this hypothesis that agnostids are free-swimming predators.
Second, the article points out that agnostids may dwelled on the seafloor and survived by scavenging dead organisms or by grazing on bacteria. However, the lecturer argues that usually marine animals who dwell on seafloor, they move slowly and stay locally, but the fossil shows that agnostids could move to other place.
Third, the author notes that agnostids were parasites, living on and feeding off larger organisms. The lecturer opposed this point by explaining that if they were parasites, their population would have certain limits because a large amount of population live on the host, the host will die. But the fossil shows the population of agnostids were large, so we can rule out this assumption also.
| Post date | Users | Rates | Link to Content |
|---|---|---|---|
| 2023-09-05 | YasamanEsml | 86 | view |
| 2023-06-19 | Vivian Chang | 76 | view |
| 2023-02-07 | reza_fattahi | 73 | view |
| 2023-01-30 | reza_fattahi | 86 | view |
| 2023-01-30 | reza_fattahi | 75 | view |
- Did bees a type of insect exist on Earth as early as 200 million years ago Such a theory is supported by the discovery of very old fossil structures that resemble bee nests The structures have been found inside 200 million year old fossilized trees in the 73
- The Phoenicians The Phoenicians were an ancient civilization that emerged in the eastern Mediterranean around 1500 BCE They were known for their seafaring skills and played a significant role in trade and commerce While some historians have suggested that 80
- In 1957 a European silver coin dating to the eleventh century was discovered at a Native American archaeological site in the state of Maine in the United States Many people believed the coin had been originally brought to North America by European explore 76
- Do you agree or disagree with the following statement Nowadays it is better for children to grow up in the countryside than in a large city Use specific reasons and examples to develop your essay 80
- Do you agree or disagree with the following statement Workers are more satisfied when they have many different types of tasks to do during the workday than when they do similar tasks all day long Use specific reasons and examples to support your answer 60
Grammar and spelling errors:
Line 1, column 69, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...tids were a group of marine animals, and paleontologists have three different the...
^^
Line 7, column 312, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
... the host will die. But the fossil shows the population of agnostids were large, ...
^^
Line 7, column 389, Rule ID: ALSO_SENT_END[1]
Message: 'Also' is not used at the end of the sentence. Use 'as well' instead.
Suggestion: as well
...rge, so we can rule out this assumption also.
^^^^
Transition Words or Phrases used:
also, but, first, however, if, may, second, so, third, well, in contrast
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 7.0 10.4613686534 67% => OK
Auxiliary verbs: 12.0 5.04856512141 238% => Less auxiliary verb wanted.
Conjunction : 7.0 7.30242825607 96% => OK
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 25.0 22.412803532 112% => OK
Preposition: 23.0 30.3222958057 76% => OK
Nominalization: 4.0 5.01324503311 80% => OK
Performance on vocabulary words:
No of characters: 1237.0 1373.03311258 90% => OK
No of words: 237.0 270.72406181 88% => More content wanted.
Chars per words: 5.2194092827 5.08290768461 103% => OK
Fourth root words length: 3.92362132708 4.04702891845 97% => OK
Word Length SD: 2.5257385376 2.5805825403 98% => OK
Unique words: 128.0 145.348785872 88% => More unique words wanted.
Unique words percentage: 0.540084388186 0.540411800872 100% => OK
syllable_count: 366.3 419.366225166 87% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 4.0 3.25607064018 123% => OK
Article: 10.0 8.23620309051 121% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 3.0 1.51434878587 198% => OK
Preposition: 1.0 2.5761589404 39% => More preposition wanted as sentence beginning.
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: 21.0 21.2450331126 99% => OK
Sentence length SD: 33.2468851458 49.2860985944 67% => OK
Chars per sentence: 112.454545455 110.228320801 102% => OK
Words per sentence: 21.5454545455 21.698381199 99% => OK
Discourse Markers: 6.54545454545 7.06452816374 93% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 3.0 4.19205298013 72% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 5.0 4.45695364238 112% => OK
Sentences with neutral sentiment: 5.0 4.27373068433 117% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.26251920459 0.272083759551 96% => OK
Sentence topic coherence: 0.116892965438 0.0996497079465 117% => OK
Sentence topic coherence SD: 0.0740293566211 0.0662205650399 112% => OK
Paragraph topic coherence: 0.162254786432 0.162205337803 100% => OK
Paragraph topic coherence SD: 0.024052238593 0.0443174109184 54% => OK
Essay readability:
automated_readability_index: 13.9 13.3589403974 104% => OK
flesch_reading_ease: 58.62 53.8541721854 109% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 10.3 11.0289183223 93% => OK
coleman_liau_index: 13.0 12.2367328918 106% => OK
dale_chall_readability_score: 8.01 8.42419426049 95% => OK
difficult_words: 50.0 63.6247240618 79% => More difficult words wanted.
linsear_write_formula: 9.0 10.7273730684 84% => OK
gunning_fog: 10.4 10.498013245 99% => OK
text_standard: 10.0 11.2008830022 89% => OK
What are above readability scores?
---------------------
Rates: 76.6666666667 out of 100
Scores by essay e-grader: 23.0 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.