Agnostids were a group of marine animals that became extinct about 450 million years ago. TPO43 Integrated Writing

TOEFL, IELTS, Personal Statement and CV Proofreading Services. TOEFL Writing Agnostids were a group of marine animals that became extinct about 450 million years ago. TPO43 Integrated Writing

  • Anonymous
    November 27, 2019 at 3:07 pm

    TPO 43: Agnostids were a group of marine animals that became extinct about 450 million years ago. 

    In  the  reading,  the  author  lists  three  theories  about  the  way  agnostids  lived.  But  the  professor  believes  every  theory  have  a  weakness.

    Firstly,  the  reading  passage  claims  that  agnostids  may  have  been  free-swimming  predators  living  on  hunting  smaller  animals  since  other  types  of  primitive  arthropods  were  strong  swimmers  and  active  predators.  Yet,  the  professor  argues  that  unlike  other  arthropods,  agnostids  do  not  own  big  detective  eyes.  What’  more,  their  eyes  are  even  blind.  The  professor  also  points  that  they  lack  other  sensory  organs  to  help  them  catch  smaller  animals.

    Secondly,  in  the  reading  passage,  it  is  said  that  agnostids  may  dwell  on  the  seafloor  due  to  other  types  of  primitive  arthropods  do  the  same  way.  On  the  contrary,  the  professor  holds  the  view  that  seafloor  animals  usually  occupy  on  a  local  small  area  and  move  slowly  but  agnostids  can  spread  in  a  large  area  with  high  speed.  So  this  ability  is  unusual  for  seafloor  dwellers.

    Finally,  the  passage  says  that  agnostids  are  parasites  since  many  modern-day  arthropods  exist  as  parasites.  However,  the  professor  points  out  that  the  parasites’  population  is  very  small  in  order  to  prevent  killing  the  animal  they  live  on.But  fossil  records  that  agnostids  have  a  very  large  population.

    November 27, 2019 at 3:10 pm

    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.
    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.



    ow listen to part of a lecture on the topic you just read about.

    Unfortunately, each of the three theories about how agnostids lived has a serious weakness.

    First, we know that other types of arthropods swam in the open ocean, hunting their prey. However, all of those arthropods had large, well-developed eyes. Vision is one of the best ways for a predator to track its prey. But agnostids had tiny, poorly-developed eyes and were sometimes completely blind! This seems to rule out the idea that they were predators. If they did chase after prey, they would have had some other, special sensory organ to help them find prey, but there’s no evidence of this in the fossil record.

    Second, it seems unlikely that agnostids lived on the seafloor. Animals that are seafloor dwellers typically don’t have the ability to move very fast or very far. They move slowly across the seafloor and stay in localized areas rather than spreading to new areas. So, typically we find each seafloor dweller species occupying a small geographic area where it had originated and nowhere else. However, many agnostid species inhabited multiple geographic areas spread across large distances. This suggests that agnostids were able to move from one area to another pretty fast. The ability to move easily across large distances would be highly unusual for seafloor dwellers.

    Finally, the parasite theory. Well, one thing that’s typical of parasites is that their populations are not very large. Parasite populations have to stay within certain limits, because if there were too many parasites, they would kill off the host organisms they live on. But we’re pretty sure that the populations of many agnostids were in fact very large. We can tell because for many species we’ve been able to find vast amounts of fossilized individuals. So, the great size of agnostid populations seems to rule out the theory they were parasites.

    November 28, 2019 at 9:17 pm

    Score: Ungraded

    I will send you screenshots to illustrate specific problems/errors.

    December 20, 2019 at 3:23 am

    Your revised essay?

    Kevin —
    University: Hainan Normal University
    Nationality: Chinese
    January 30, 2024 at 1:55 pm

    In the reading, the writer talks about three theories to explain how agnostids may have lived. The lecture in the listening, however, believes that none of the three theories is persuasive and uses specific reasons and details to support her claim.

    To begin with, the reading passage states that the agnostids were strong sea predators and hunted the small prey for survival. In the listening, however, the professor argues that the significant difference between the agnostids and other type of free-swimming predators is the eyes. To track the prey, general predator need a large eyes to help them. However, it’s not difficult to find that agnostids are blind so that never could them have ability to capture the prey.

    In addition, the writer points out that agnostids may dwell in seafloor. On the contrary, the lecture disagrees with the idea by demonstrating the fact that seafloor dwellers are not be able to swim fast, which means that they just stay in local environment rather than move to new areas. But agnostids’s fossils would be found from place to place so that we could conclude that it has a extremely fast speed.

    The last but not least, the reading passage mentions that anostids are parasites which lives on other larger animals. Yet the lecturer finds this method indefensible because the population of the general parasites are not large. If the number of parasites is too large, they wouldn’t live in certain limits, and then too many parasites would kill the animal they have lived. It does not coincide with agnostids’ situation because the group of them is very large.