The reason as to why fungi fossils seem so rare is that they are usually microscopic and often difficult or impossible to identify.
Not much information on fungi fossils has been documented. This could be because fungi fruiting bodies consist of soft, fleshy and easily degradable tissues which due to their poor integrity do not keep or preserve as well as animal tissue.
Even when available, it takes a trained eye to recognize fungal fossils. Not many people have the training and expertise to recognize the fossils.
Most scientific questions are based off of theory.
The remains of fossils give scientists clues as to what the world may have been like a long tome ago. If fish fossils are found on the side of a mountain, there may have been a lake there. If a skeleton is found, they can decide what creature it was.
Plant uptake is the process which converts inorganic phosphorus in a rock to an organic form of phosphorus.
The lithosphere sits on top of the asthenosphere.
