Kids, as you hunt, you can put all the fossils you find in this cart ... The Law of Superposition means that when we see a stack of rock layers, the oldest rocks are usually on the bottom ...

it disappears and cannot reappear in younger rocks (Figure 4). Fossil species that are used to distinguish one layer from another are called index fossils. Index fossils occur for a limited ...

it disappears and cannot reappear in younger rocks (Figure 4). Fossil species that are used to distinguish one layer from another are called index fossils. Index fossils occur for a limited ...