LSAT 149 | Section 3 | Logical Reasoning: Q14

LR Question 14 Explanation

QUESTION TEXT: Several Tyrannosaurus rex skeletons found in North…

QUESTION TYPE: Most Strongly Supported

FACTS:

1. T. rex was the only large carnivore in North America at the time that it lived.
2. Some T. Rex skeletons had teeth marks that must have been made by large carnivores.
3. The tooth marks could only have been from fighting or feeding.
4. The toothmarks couldn’t have been made if the animal had been alive.

ANALYSIS: We can conclude: A Tyrannosaurus rex made the tooth marks found not on the skeleton of the other T. rex. And the T. rex whose skeleton was bitten must have been dead at the time the tooth marks were made.

The only reasons for tooth marks would be if the T. rex‘s fought each other, or if one T. rex ate the other. Since the T. rex with marks was dead, it must be that the other T. rex ate it. After all, no other large carnivore could have made the marks.

___________

1. No other carnivores were mentioned! And we know the tooth marks could only have been made by a large carnivore.
2. This goes too far. We can say the marks mean that carnivores sometimes fed on other carnivores. But we can’t say it’s common. The stimulus only says that “several” T. rex skeletons were found. That doesn’t support us saying this kind of feeding happened frequently.
3. CORRECT. This is supported. The marks could only be from combat or feeding. But it couldn’t have been combat, because but the marks couldn’t have been made on a live animal.
    
   So, something fed on the T. rex when it was dead. And, the only animal capable of making the marks was a large carnivore. Since the T. rex was the only large carnivore, it’s thus the only animal that could have made the marks, which were feeding marks.
    
   And, since the marks were made during feeding, and the T. rex was eating an animal of its own species, that’s cannibalism.
    
   The “sometimes” is appropriate. We only know of “several” skeletons this happened to. May not be common.
4. This isn’t supported. When you are in combat, you are alive. But the stimulus said the marks couldn’t have been made on a live animal.
5. Who knows? The stimulus didn’t tell us about other continents, or about any other animals.

Recap: The question begins with “Several Tyrannosaurus rex skeletons found in North”. It is a Most Strongly Supported question. Learn more about LSAT MSS questions in our guide to LSAT Logical Reasoning question types.