Why have we not found examples in the fossil record of every animal that ever lived on earth? select all that apply. select all that apply. many fossils remain buried. we can only find them when they are exposed by erosion or excavation. to become a fossil, an animal must remain buried for thousands or millions of years until it (and the layer around it) turns to rock. it is just a matter of time before we find them all. rocks contain the history of all life, if you know where to look. to become a fossil, an animal must be quickly and completely buried in ash or sediment before it has a chance to decompose?