recent comparative study

[akhpad]

Source: Knewton

A recent comparative study of the skeletal remains of dinosaurs and the ancestors of crocodiles, crurostarsans, has shed new light on the condition of dinosaurs in the long period prior to their extinction. According to the fossil record, both dinosaurs and crurostarsans survived a mass extinction of many animal groups 225 million years ago. Few crurostarsans endured a second, similar extinction only 25 million years later, whereas the dinosaurs, who underwent little or no evolution between this event up until the point of their extinction, thrived and multiplied. Researchers were surprised by this finding because the skeletal remains of crurostarsans indicate that these animals appeared in a greater variety of shapes and forms than dinosaurs, with more physical variety implying a stronger ability to adapt and thus survive by changing lifestyles, diets, and habitats. So, contrary to former beliefs, rather than being in a state of decline prior to their extinction, dinosaurs actually thrived and dominated.

In light of the recent study, researchers have attempted to devise an explanation for the dinosaurs' supremacy during the 135 million years prior to their extinction. At this point, however, no satisfactory scientific explanation has been put forth, and researchers currently consider that "luck" played the greatest role in the dinosaur's triumph. According to Dr. Michael Benton, the crurostarsans were essentially eliminated while the dinosaurs began to thrive. And, just as there is still no scientific explanation for the survival of the dinosaurs, researchers similarly lack an explanation for the sudden demise of the better-adapted crurostarsans.

According to the passage, researchers believe that the varied physical characteristics of crurostarsans

A: question the methods employed by the researchers in the recent study
B: offer a scientific explanation for why the dinosaurs outlived the crurostarsans
C: cast doubt on a previously held belief about the state of dinosaurs prior to their extinction
D: refute a previously held belief about the condition of dinosaurs prior to their extinction and offer a new scientific theory to explain why this belief is incorrect
E: point out that the theory of natural selection is inadequate to explain the survival of the dinosaurs over the crurostarsans

Can someone explain about C and E? Why one not other?

OA: C

[gig92]

Source: Knewton

A recent comparative study of the skeletal remains of dinosaurs and the ancestors of crocodiles, crurostarsans, has shed new light on the condition of dinosaurs in the long period prior to their extinction. According to the fossil record, both dinosaurs and crurostarsans survived a mass extinction of many animal groups 225 million years ago. Few crurostarsans endured a second, similar extinction only 25 million years later, whereas the dinosaurs, who underwent little or no evolution between this event up until the point of their extinction, thrived and multiplied. Researchers were surprised by this finding because the skeletal remains of crurostarsans indicate that these animals appeared in a greater variety of shapes and forms than dinosaurs, with more physical variety implying a stronger ability to adapt and thus survive by changing lifestyles, diets, and habitats. So, contrary to former beliefs, rather than being in a state of decline prior to their extinction, dinosaurs actually thrived and dominated.

In light of the recent study, researchers have attempted to devise an explanation for the dinosaurs' supremacy during the 135 million years prior to their extinction. At this point, however, no satisfactory scientific explanation has been put forth, and researchers currently consider that "luck" played the greatest role in the dinosaur's triumph. According to Dr. Michael Benton, the crurostarsans were essentially eliminated while the dinosaurs began to thrive. And, just as there is still no scientific explanation for the survival of the dinosaurs, researchers similarly lack an explanation for the sudden demise of the better-adapted crurostarsans.

According to the passage, researchers believe that the varied physical characteristics of crurostarsans

A: question the methods employed by the researchers in the recent study
B: offer a scientific explanation for why the dinosaurs outlived the crurostarsans
C: cast doubt on a previously held belief about the state of dinosaurs prior to their extinction
D: refute a previously held belief about the condition of dinosaurs prior to their extinction and offer a new scientific theory to explain why this belief is incorrect
E: point out that the theory of natural selection is inadequate to explain the survival of the dinosaurs over the crurostarsans

Can someone explain about C and E? Why one not other?

Facts matching answer -- The bold part above gives details about what the question is asking.
Ans: C

[loveusonu]

Researchers were surprised by this finding because the skeletal remains of crurostarsans indicate that these animals appeared in a greater variety of shapes and forms than dinosaurs, with more physical variety implying a stronger ability to adapt and thus survive by changing lifestyles, diets, and habitats. So, contrary to former beliefs, rather than being in a state of decline prior to their extinction, dinosaurs actually thrived and dominated.

My interpretation: The finding surprised researchers because of the variety of shapes and forms
This means that this finding actually supports the earlier belief and hence new report surprised the researchers.

C is incorrect(shell game) as it seems opposite answer with this interpretation. This interpretation supports earlier belief and not cast doubt.
E should the answer according to me.

what's OA?

[paddle_sweep]

I will go with 'E'. Pls post OA.

[abhigang]

IMO E .

Not C because the varied characteristics of "Chru" (whatever on earth that was) was put into the argument to shown that though the fossil studies indicate this variation, yet the findings(Dinosaurs thrived and multiplied) are opposite

[akhpad]

Above explanation is not convincing to me.

I am really confused over C and E.

[loveusonu]

Above explanation is not convincing to me.

I am really confused over C and E.

C is opposite answer

[Alex_Knewton]

Hmmm...

I think I have the solution to some of the problems discussed in this thread: after checking and double-checking the Knewton source, it looks like this question is slightly misquoted. The stem of this question actually refers to a DIFFERENT set of answer choices, and these answer choices actually correspond to a much simpler stem:

"What is the primary purpose of the passage?"

Thus, the OA is choice C, because natural selection is not the PRIMARY purpose of the passage. Choice C serves as the primary purpose- scientists "lack an explanation" for the recent findings that indicate that dinosaurs may have thrived and dominated before extinction. Thus, the previous beliefs (that dinosaurs were in decline) is thrown into doubt.

Best of luck!

[aspire_mba2013]

A recent comparative study of the skeletal remains of dinosaurs and the ancestors of crocodiles, crurostarsans, has shed new light on the condition of dinosaurs in the long period prior to their extinction. According to the fossil record, both dinosaurs and crurostarsans survived a mass extinction of many animal groups 225 million years ago. Few crurostarsans endured a second, similar extinction only 25 million years later, whereas the dinosaurs, who underwent little or no evolution between this event up until the point of their extinction, thrived and multiplied. Researchers were surprised by this finding because the skeletal remains of crurostarsans indicate that these animals appeared in a greater variety of shapes and forms than dinosaurs, with more physical variety implying a stronger ability to adapt and thus survive by changing lifestyles, diets, and habitats. So, contrary to former beliefs, rather than being in a state of decline prior to their extinction, dinosaurs actually thrived and dominated.

In light of the recent study, researchers have attempted to devise an explanation for the dinosaurs' supremacy during the 135 million years prior to their extinction. At this point, however, no satisfactory scientific explanation has been put forth, and researchers currently consider that "luck" played the greatest role in the dinosaur's triumph. According to Dr. Michael Benton, the crurostarsans were essentially eliminated while the dinosaurs began to thrive. And, just as there is still no scientific explanation for the survival of the dinosaurs, researchers similarly lack an explanation for the sudden demise of the better-adapted crurostarsans.

According to the passage, researchers believe that the varied physical characteristics of crurostarsans

A: question the methods employed by the researchers in the recent study
B: offer a scientific explanation for why the dinosaurs outlived the crurostarsans
C: cast doubt on a previously held belief about the state of dinosaurs prior to their extinction
D: refute a previously held belief about the condition of dinosaurs prior to their extinction and offer a new scientific theory to explain why this belief is incorrect
E: point out that the theory of natural selection is inadequate to explain the survival of the dinosaurs over the crurostarsans

Can someone explain about C and E? Why one not other?



-----

My take on why C is correct?


Key words -
Surprise and So, contrary to former beliefs


From the 1st paragraph,

Researchers were surprised by this finding because the skeletal remains of crurostarsans indicate that these animals appeared in a greater variety of shapes and forms than dinosaurs, with more physical variety implying a stronger ability to adapt and thus survive by changing lifestyles, diets, and habitats. So, contrary to former beliefs, rather than being in a state of decline prior to their extinction, dinosaurs actually thrived and dominated.


Since , its contradicting the previous held belief. So it casts doubt ...


C: cast doubt on a previously held belief about the state of dinosaurs prior to their extinction



The option E

E: point out that the theory of natural selection is inadequate to explain the survival of the dinosaurs over the crurostarsans


This doesn't point out that the theory of natural selection is inadequate to explain the survival of the dinosaurs over the crurostarsans - Because , if you refer the 2nd paragraph it says researchers have attempted, however at this point, no



The theory is not inadequate but the researchers couldn't find it out - at this time _ in lay man language the research file is not close - researchers are still working on it....Nothing has been sure shot declared.

In light of the recent study, researchers have attempted to devise an explanation for the dinosaurs' supremacy during the 135 million years prior to their extinction. At this point, however, no satisfactory scientific explanation has been put forth, and researchers currently consider that "luck" played the greatest role in the dinosaur's triumph.


So, C is the answer

[vikram4689]

Well NAtural slection is nowhere mentioned in passage.So reject E. Doubt can be in C & D

D- has problematic clause after "and" characterstics do not offer a new scientific theory.

C - is correct, because Researchers were surprised that even though crurostarsans had varied characterstics they died. So reachsearchers must have believed that crurostarsans to survive more than dinosaurs but oppo. happened , so it casts doubt.