LSAT question

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LSAT question

by mrinal2100 » Thu Feb 02, 2012 4:05 am
Paleontologists have discovered fossils of centipedes that are 414 million years old.these fossils are at least 20 million older than the
earliest land dwellling animals previously identifed.the paleontologists are confident that these centipedes live on
land,even thought the fossilsed centipedes were discovered in rock that also contained fossilized remains of animals
known to be water dwelling.

the paleontologists view would be least supported by the truth of which of the following?
1)the legs of the fossilied centipedes were particularly suited to being a means of locomotive on land.
2)all the centipedes that were previously discovered were land dwellers
c)the rock in which fossilzed centepeds were found were formed from mud flats that were occasionally covered by river water
d)fossils of the earliest land dweling animals that had previously been identified were found in rocks that did not
contain fossilized reamins of water dwelling animals
e)Fossils of spiders with respiratory systems adapted only to breathing air were found int he same rock as the centipede
fossils


i wanted to know why the choice c is wrong

according to the explanation provided by kaplan

"this statement would offer an explanation of how the fossilsof water dwelling animals came to be found in the rocks.
Such an explanation would further support the notion that the new found cetipedes were land dwellers by clearing up the
major ground for objection"

in the chocice c nowhere water dwelling is mentioned so why in the explanation they have mentioned about the water
dwelling animals.the choice c clearly explains that the centipedes could have lived in water.
D
Source: — Critical Reasoning |

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by MakeUrTimeCount » Thu Feb 02, 2012 6:28 am
The thread talks about Rock, Water dwellers and Centipedes.
If Rock has mud flats that were occasionally covered by river water, then Rock was made underwater. This finding raises the question: "how come centipedes were found on Rocks?"

So the point is important.

On the other hand, point D talks about the relationship between earliest land dwelling animals and rocks. This is out of scope.
Ans: D

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by StoneBlack » Thu Feb 02, 2012 8:20 am
i think C can be interpreted as : centipedes lived on land areas (mud flats) which were sometimes covered by water and hence fossils or water dwelling animals were also found. It strengthens the argument.

D fails to talk about centipedes at all. It has to be the one which is least supportive. It's neither weakening nor strengthening.

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by mrinal2100 » Thu Feb 02, 2012 11:13 pm
@makeurtimeCount you mentioned that "If Rock has mud flats that were occasionally covered by river water, then Rock was made underwater".
Choice C mentions that the fossils of centepedes where found in rock..so it might be they died in water and were present in the mud flats from which the rock was formed.this proves that they could have lived in water...

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by MakeUrTimeCount » Fri Feb 03, 2012 12:52 am
Hi Mrinal,

Yes, you are absolutely right.

Option c), will help us conclude whether centepeds were land-dwellers or water-dwellers.

On the other hand, option d) is totally irrelavant. Even if we know about any connection between earliest land dweling animals (which are not centipeds) and rock, we won't be able to conclude anything for matter under study.


Moreover, we are to select least relavant option. So D stands out.

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by chris@magoosh » Fri Feb 03, 2012 6:38 pm
Answer choice (C) actually provide support for the scientist's argument. Basically, there is a discrepancy in the scientist's
argument, how is it that these supposedly land-dwelling centipedes are in the same rock as remains of water-dwelling
animals.

(C) helps account for this discrepancy by providing a reason for the fossils of water-dwelling animals in the same rock:
the rock was formed from mud flats that were sometimes covered by water.

(D) if anything weakens the scientist's claim. It is important to note that (D) is not irrelevant. It brings up the once
thought of earliest land animals. They were found in a rock that did not contain the remains of water-dwelling animals.
How is it then that these purported earliest land-dwelling creatures inhabit the same rock as water-dwelling creatures?
That would suggest that these centipedes weren't actually land-dwelling.

Hope that makes sense :)