Logical Reasoning

PT10 · S1 · Q9 Paleontologists have discovered fossils of centipedes

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Paleontologists have discovered fossils of centipedes that are 414 million years old.

Paleontologists' View

These centipedes lived on land.

Evidence

The fossils were discovered on a rock.

Evaluate

There's mostly counterevidence to the idea that these centipedes were land dwelling.

These centipedes are at least 20 million years older than the earliest previously identified land-dwelling animals. And the rock they were found in contains remains of known water-dwelling animals.

Goal

Let's get rid of four answers that would help the paleontologists argue that this centipede was a land-dweller, or find an answer that makes it sound like it wasn't a land-dweller.

9.

The paleontologists’ view would be LEAST supported by the truth of which one of the following?

  1. The legs of the fossilized

    Opposite Impact

    This strengthens the idea that the centipedes were land-dwellers, since their legs seemed built for moving on land.

    1% picked this

  2. All of the centipedes that

    Opposite Impact

    This strengthens the plausibility that the centipedes were land-dwellers since every previously discovered centipede has been a land-dweller.

    3% picked this

  3. The rock in which the

    Opposite Impact

    This allows the paleontologists to address some of the potential counterevidence. We might say, "If they were land dwellers, then how come we found them on a rock that contained the remains of water-dwellers?" And this answer lets them respond, "That's just because this rock was sometimes covered in water. It wasn't an underwater rock. But that's how fossils of water-dwellers got in there."

    27% picked this

  4. Correct

    Fossils of the earliest land-dwelling

    Why this is right

    This undermines the plausibility that the centipedes were land-dwellers. Every other time we've discovered a land-dweller fossil in a rock, it hasn't been sharing that rock with water-dwelling animals. These centipedes were found in a rock with water-dwelling animals. Thus, this doesn't look like an instance of finding a land-dweller.

    Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.

    64% picked this

  5. Fossils of spiders with respiratory

    Opposite Impact

    This allows the paleontologists to address some of the potential counterevidence. We might say, "If they were land dwellers, then how come we found them on a rock that contained the remains of water-dwellers?" And this answer lets them respond, "Look, this rock also had land-dwellers on it. These spiders breathed only air, so you know they weren't an underwater organism."

    5% picked this

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