You fossilize something by having it first fall in rock... then it gets covered in setimentary rock.... most likely and stays over in rock for many years. It then gets covered in rock and hardens and is fossilized!
First of all, the animal that died had to be quickly and fully covered by a substance that prevents oxygen getting to the corpse and starting a process of decomposition. Drowning in mud or quickly getting covered by a thick layer of sand would be some of the things to do the trick.
Over a very considerable period of time, the original minerals of the body parts would mostly dissolve, the resulting 'empty' spaces being replaced by other, rock-like minerals that form an exact copy of the original parts.
Different chemical and physical processes create fossils. Some of these processes are freezing, drying and encasement in tar or resin.
fossilized shell
Asphalt is not a rock, but is produced from the remains of fossilized organisms.
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Diatoms
Sediment covers dead organisms to be fossilized. On land the organism could fall into a lake or swamp, or it can be covered by sand or volcanic ash.
THEY ARE SORTED BY SIZE
fossilized shell
A biostrome is a horizontally-bedded stratum of fossilized remains of sedentary organisms.
Asphalt is not a rock, but is produced from the remains of fossilized organisms.
Dead organisms that were living million / billion/S of years ago.
Rapidly buried by sediments
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Less than 1% of all organisms that die become fossilized.
Microfossils are fossilized remains of single-celled organisms similar to modern bacteria. They exist in rocks that are more than 3.5 billion years old.
An ancient, rainforest lateritic soil buried by basalt lava flows
Amber is fossilized tree resin, while most fossils are made from the remains of organisms.
It took many years of evolution for complex, multi-celled organisms to develop. Single celled organisms were the first that were around to be fossilized.