Carbon dating fossil record
On the contrary, it is very difficult to find fossils of small, soft bodied, geographically restricted organisms, due to their relative rarity and low chance of preservation.Larger specimens (macrofossils) are more often observed, dug up and displayed, although microscopic remains (microfossils) are actually far more common in the fossil record.Also, material from erosion (called sediment) may also accumulate on top of it with time.Today most geologists and agriculture experts can tell the rate at which sediments deposit at a particular place based on the specific circumstances in that area.Fossils of soft tissues such as brain tissue or liver etc are very rare due to the rapid decomposition they undergo and the fact that they do not mineralize during the life of the organism.Fossils may also consist of marks left behind by an organism such as foot prints or the faeces.Other forms include endocasts where the soft tissue was encased in a layer of say mud and made an impression on the inside of the mud encasing and then decomposed and the mud fragment later hardened maintaining the imprint from the encased organ(s).Fossilization is a very rare occurrence, because most components of formerly-living things tend to decompose very quickly after death.
For example if a cat dies in the bush with time plants living, growing and dying on top of it will accumulate.
Therefore if we find a fossilized snake buried in the ground we can tell when this snake died and from that we can tell when this snake lived.
If we can find other fossilized materials in that same layer in that same area we can get an idea of what food materials were available to this snake when it was alive, as well as what kind of environment it lived in at that time.
These organisms lived in colonies on the exposed surfaces of rocks.
In some specimens the details are clear enough to see the cell structure with a microscope.