According to the principle of faunal succession, what must be true of the fossils on a layer below?
younger than the fossils above
older than the fossils in the layer above
the same age as the fossils in the layers above
identical to the fossils in the layers above
According to the principle of faunal succession, what must be true of the fossils on a layer below?
younger than the fossils above
older than the fossils in the layer above
the same age as the fossils in the layers above
identical to the fossils in the layers above