While on a dig, a paleontologist finds two fossils. The more deeply buried one is an animal that appeared to have a few spiky projections resembling feathers. The second is an imprint of an animal that had fully formed feathers like those of modern birds. The paleontologist suspects the first animal was an ancestor of the second one. What would be the best thing for him to do next to test his hypothesis?
Look for fossils of more advanced forms in the rock layers above the second fossil.
Look for more fossils of the two animals he has already found in the same two rock layers.
Look for other fossils of transitional forms in the rock layers between the two fossils.
Look for fossils of more primitive forms in the rock layers below the first fossil.