Radiometric dating definition for kids
Petrification happens when the organic material is slowly replaced by minerals. Making a fossil is tricky and the conditions have to be just right.
Some fossils are the actual remains of a plant or animal that has been frozen in ice or trapped in a substance like sap. Despite this, there are several different ways for a living thing to become a fossil.
The two fossil categories can be broken down further.
When we think of fossils, the first things that come to mind are the bones of dinosaurs; but a fossil can be anything.
Footprints, flowers, even droppings; all of these things can be turned into fossils under the right conditions.
A cast fossil is a fossil made when an organism that is buried in sediment decays and leave behind a mold, or hollow impression in its shape.
A cast fossil is like a mold fossil, but in the case of a cast fossil the mold has been filled with minerals.