Biostratigraphy

Biostratigraphy is a very big and fancy word that tells us about the really old things that used to be alive, like dinosaurs! Scientists use biostratigraphy to study the age of the rocks and the fossils in them.

Scientists know that different animals and plants lived at different times in history, so they use the fossils of these animals and plants to figure out how old rocks are. They study the layers of rocks and the fossils they find in them to put them in order from oldest to youngest.

For example, let's imagine that we have a bunch of rocks stacked on top of each other like a cake! We know that the layer on the bottom is the oldest because it was put there first. As we go up the cake, we see different colors and shapes in each layer.

If we looked closer, we might find some fossils in the rocks. The fossils in the bottom layer will be different from the fossils in the top layer because animals and plants that lived a long time ago are different from the animals and plants that live now.

Scientists can then compare the fossils in the different layers to other rocks from other places to find out how old they are. It's like putting together a big puzzle, but instead of using shapes and colors, they use fossils and rock layers!