Question

scientists discovered the fossil of an unknown species in a core sample of rock. fossils of previously discovered species with known age ranges were also found in the undisturbed surrounding rock layer. image: ages of known species, positions of fossils in core sample, relative ages of known species, key: species 1, species 2, species 3, species 4, species 5 which statement accurately describes the age range of the unknown species? a. it existed in age range w because it appears in the core sample with species 2. b. it existed in age range x because it appears in the core sample after species 2 but before species 3. c. it existed in age range y because it existed in the same period as both species 2 and 4. d. it existed in age range z because it existed at the same time as species 5.

Explanation:

To determine the age range of the unknown species, we analyze the core sample and the relative ages of known species:

• Option A: Species 2's age range is not W (from the relative ages graph, Species 2's arrow doesn't point to W). So this is incorrect.
• Option B: The unknown species is with Species 2 and 4 (and others), not "after Species 2 but before Species 3". Also, the age range X doesn't align with the co - occurring species. So this is incorrect.
• Option C: The unknown species is in the same core layer as Species 2 and Species 4. From the relative ages graph, the age range where both Species 2 and 4 overlap is Y. So this is correct.
• Option D: The unknown species is not in the same layer as Species 5, so it doesn't exist at the same time as Species 5. So this is incorrect.

Answer:

C. It existed in Age Range Y because it existed in the same period as both Species 2 and 4.