CBSE Class 10 Answered
Mold Fossils - When an organism dies its body gets buried under the ground and slowly and gradually layers of sediments start forming on its remains. The fossils that are discovered deepest under the ground are believed to be oldest. Some fossils are discovered as imprints formed on the first layer of sediment that was formed on them these fossils are called the mold fossils.
Chemo Fossils - These are not the preserved body parts of the organisms but they are the chemicals that have been left behind their bodies. Such chemicals are discovered beneath the earth and are believed to be the bio signals of the organisms.
Cast Fossils - The cast fossils just like the mold fossils are only the imprints of the organisms.
Trace Fossils - These are various body parts of the organisms or can be nests, eggs, feces or even foot prints of the old extinct animal.
True Form Fossils - The true fossils or the direct fossils are the original organism trapped within in ice, tar or tree sap preserved for centuries by nature.