Why don't we have a complete fossil record of all life that's ever lived? Fossil formation requires a rare mix of physical and biological conditions. Fossils must be exposed at Earth's surface to have a chance of being found. Fossils can be destroyed when rocks erode, melt, or change composition.
Explanation:
For many reasons, the fossil record is not complete. Most organisms decomposed or were eaten by scavengers after death. Many species lacked hard parts, which are much more likely to fossilize. Some rocks and the fossils they contained have eroded and disappeared.
Sediment has to cover the bones in order for fossilization to take place
Explanation:
Fossil formation requires a mix of physical and biological conditions. Fossils have to be exposed in oder to find them too, so there might be some that are just too deep in the earth for us to find them
This is a symbiotic relationship, where both the partners, fungi, and plants are mutually benefitted by exchange of nutrients and none of them is being harmed by other's presence. It is a mutual cooperation and helps both organisms in survival and nutrition.
