The oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
<h2>Rock layers from oldest to youngest</h2>
The rock layers that is located farthest from the ground surface are considered as the oldest rock layers and rock layers that are closest to the ground surface are considered as the youngest. A fossil is the remains or traces of plants and animals that lived long ago.
<h3>Presence of fossil</h3>
Those fossils which are present at the bottom of the rock layers are considered as the oldest fossil followed by the upper layer's fossil and so on. The fossils present at the top layer are the youngest fossils so we can conclude that oldest fossils present at the bottom of rock layer whereas the youngest fossils are present in the top layer.
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Combines photosynthesis and heterotrophic nutrition
The two main functions are replication and expression.
