#14 - Several Tyrannosaurus rex skeletons found in North

[Administrator]

Please post your questions below! Thank you!

[freddythepup]

Hi, can you please explain more in depth how to go about this question. I got E at first and then picked D when I tried the problem again. I chose E at first because I thought since T rex were the only large carnivores of its time in North America, then the tooth mark that it got cold only have been from another large carnivore outside of North America. Then when I tried the problem again I thought E might be too out of the scope because the stimulus says nothing about carnivores outside of North America, so I picked D because I thought that (Since we know the mark was received when the animal was alive), then the T rex must have gotten the mark when it was fighting with another T rex. Can you explain why my approaches for both of these answer choices are wrong? And can you also explain why C is the right answer? I thought the answer was too extreme and crossed it out both times I tried the problem. Thanks.

[Rachael Wilkenfeld]

Hi Freddy,

This is a must be true question. When we read the stimulus, we see a few facts.

1) Some T. rex skeletons in N. America had teeth marks that only a large carnivore could have made.
2) The only large carnivore in N. America at that time were other T. rex.
Inference: T. rex made the teeth marks on other T. rex.
3) The teeth marks must have resulted from either combat or feeding.
4) They couldn't have been made on a live animal.
Inference: They were not made in combat
Inference: They were made in feeding.

We want to look through the answer choices to find one that matches one of our inferences. Answer choice (C) does so by stating that sometimes T. rex engaged in cannibalism. We did not establish answer choice (D), that they engaged in combat with one another. They could have been eating T. rex who perished naturally. Answer choice (E) is also not proven by the stimulus. We know only about what occurred in North America.

Hope that helps!
Rachael

[Pragmatism]

I read this and thought, wow! They decided to give me an easy one. But then I got to the answers and got stuck. I had predicted eating the dead, but honestly I had a rough time deducing that from “cannibalism.”

I understand the meaning of cannibalism, but how does cannibalism suffice as eating the dead instead of the usual definition, “the practice of eating the flesh of one's own species.” A species can eat its own while the consumer, the species doing the eating, consumes its consumption while it is still alive. Are they assuming that during the act of being consumed the consumed is as good as dead, thus providing merit to the idea that the mark was left on the skeleton after its death?

Also, I had a big issue with this answer for another reason. The stimulus mentioned several T-rex skeletons had this mark, but yet, this answer choice states, that T-rex sometimes engaged in cannibalism. The idea of several (I think of the word many) being associated with the word sometimes seems a bit of a stretch. How do you reconcile the two?

[Jay Donnell]

Hi Pragmatism!

After several dozen dinosaur related questions on the LSAT over the years, I guess they really have to spice things up to keep them coming!

First, let's address your earlier point about the cannibalism. We know that T-Rex skeletons have tooth (bite) marks that could only have been made by large carnivores, and at the time, the T-Rex was the only large carnivore in North America. That means, we can deduce that those tooth marks on T-Rex skeletons must have come from fellow Tyrannosaurs. That should probably make you wonder why exactly these tiny-armed death machines are biting each other, but the author goes on to limit the possibilities to only either through combat or feeding. That last clause implies that these marks are nearly impossible to make on a live animal, so since it's reasonable to consider 'combat' being impossible without a live opponent to be battling, then those marks must have been made in the course of feeding.

That means that there is evidence of a T-Rex feeding on a fellow T-Rex, which perfectly matches the definition of cannibalism, which means eating your own species.


For your second point, the term 'several' is certainly enough evidence to then conclude with the strength of 'sometimes.' As a Most Strongly Supported question, or basically a Diet Must Be True, we should be especially drawn to answers that provide low levels of logical force. Wouldn't it be easier to prove that it rains in Hawaii on some days than to prove that it rains there on all or even most days? For that reason, the word sometimes here presents as a really attractive element in the answer. Knowing that it has happened on at least several occasions (and the word 'many' here would work in the exact same way) certainly allows us to conclude that it sometimes happened.

Hope that helps!

Thanks for the great question and the inspiration to put on Jurassic Park in the background while I navigate the wilderness of the forum

[Pragmatism]

Jay you have broken this down so eloquently that I am jealous. Thank you so much.

[chloemeyers]

Hi. Can you explain why answer choice B is incorrect? I chose B because the stimulus indicates that the tooth marks can only have been made by a carnivore and that they were the result of feeding, so I thought B was a fitting answer because it says that carnivores feed on other carnivores. Is this incorrect because of the word "common," since this could have been a single instance? Whereas in C "sometimes" allows the leeway for this activity to be less frequent? I understand now how the stimulus can result in answer choice C, but am still having some trouble differentiating between B and C. Thank you!

[Rachael Wilkenfeld]

Hi Chloe

You are picking up on just the right language in answer choice (B) that makes it a poor answer choice. Our stimulus is talking about very specific marks in very specific animals. They were made by large carnivores, in North America, after the animal victim was dead, when Tyrannosaurus Rex was the only possible large carnivore. Answer choice (B) talks about carnivores in general, not just large ones It also says the behavior was common, when we don't know anything more than it occurred at least several times. Both aspects of those aspects make this answer choice too broad for a must be true answer.

Hope that helps!
Rachael

[sicm91]

Hi! I am having trouble seeing how we can deduce with certainty that T. rex's engaged in cannibalism. Could it not have been the case that some hundred years later, another carnivore came into existence and fed on the dead T. rex
's? Thanks.

[Adam Tyson]

Interesting idea, sicm91! Is it possible that long after T Rex was gone, some other animal decided to gnaw on their ancient bones? Sure, why not? But that seems like a big stretch, especially when the stimulus said the marks could only have been made by combat or feeding. Are ancient bones really a source of food? We aren't supposed to make assumptions that are, as the instructions say, "by commonsense standards implausible, superfluous, or incompatible with the passage." I think we're getting dangerously into the "implausible" territory there. After all, what food would be left on those bones after all that time?

Also, you must remember that this question stem allows for some flexibility. It's not a pure Must Be True question, but instead a softer and more forgiving Most Strongly Supported variant. That means that the answer only needs to be the one that seems most reasonably supported by the facts, even if it isn't absolutely guaranteed to be true. None of the other answer choices has ANY support in the stimulus! The correct answer at least seems to be a reasonable inference, because it sure looks like T Rex did, on some occasions, scavenge off their own dead. Maybe not - maybe those tooth marks were made long afterwards, but there is at least some support for answer C, and some support is better than no support. That makes C the best answer of the options given, and thus the credited response.

So back to your very first issue: "I am having trouble seeing how we can deduce with certainty that T. rex's engaged in cannibalism. " Perhaps we cannot deduce that with certainty, but with a Most Strongly Supported question we don't have to be certain! We just have to have some supporting evidence, which we do. That's enough!