Q3 - Researcher: Dinosaur fossils come in various forms

by **mshinners** Fri Dec 31, 1999 8:00 pm

Question Type:
Strengthen

Stimulus Breakdown:
Two types of dinosaur fossils are mineralized bones or tracks in mud. Creatures that scavenged dinosaur carcasses frequented the mud flats, so it's not surprising that these two types of fossils are rarely found together.

Answer Anticipation:
This 'it's not surprising that...' conclusion is somewhat wonky. But at first glance, it seems like this would be surprising! If the scavengers hang out in the mud flats, we would expect the two fossil types to be found in the same locations. To strengthen the idea that this is not in fact surprising, we'll need some explanation for how the two fossil types get separated.

Correct answer:
(B)

Answer choice analysis:
(A) Half scope. While an argument could be made that other locations are relevant to what might happen at mud flats, by neglecting to mention bones, this answer choice is, at best, half scope.

(B) Bingo. The bones are where the scavengers leave the bodies. The dinos wouldn't walk there since they're already dead.

(C) Out of scope. This answer is trying to get you to think that they're rarely found together because there are only some bones but there are a lot of tracks - i.e., the bones are always by tracks, but since they're rare, there are a lot of tracks without bones around. However, since this answer doesn't tell us how far apart these numbers are, it doesn't speak to the situation at hand where it's rare to find them together.

(D) Out of scope. Other fossils?

(E) This might be tempting. A good test when you see a comparison such as this one is to "test" a few extreme situations that conform to the statement. I'd ask myself when analyzing this answer: What if the bone took ten seconds to mineralize and the tracks took five seconds to dry? This would conform to the comparison/answer choice, but it wouldn't impact the conclusion.

Takeaway/Pattern:
Test answer choices by coming up with extreme situations that conform to them!

#officialexplanation