For example, based on the primate fossil record, scientists know that living primates evolved from fossil primates and that this evolutionary history took tens of millions of years.
In the early-19th century, diluvial geologists hypothesized that specific surface features were evidence of a worldwide flood which had followed earlier geological eras; after further investigation they agreed that these features resulted from local floods or glaciers.
Fossils, buried under layers of sedimentary rock, are vestiges of the past.
They are usually the hard parts (bones, shells, etc.) of animals and plants that have been preserved.
Below, an ammonite dies and drops to the bottom of the body of water (1).
The mollusk’s body decomposes and sediments begin to cover the shell (2).These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth's surface is moving and changing.