What keeps some plants and animals from decaying so they become fossils?

Answer 1

In order for fossils to form, there must be a way to preserve the dead remains of animals and plants for a time so that they do not decay completely. The most common way that this occurs is on the bottom of bodies of water. When an animal of plant dies and falls into the water, the remains are sometimes covered up quickly by sediments. The layers of sediment form a protective covering to slow the process of decay.

Answer 2

The two most common mediums are mud and lava. If an animal, or a plant, is covered with mud (for example, it the animal stumbles into a sink hole, and can't get out) the mud enveloping it prevents air and bacteria from getting at the body and rotting it. Meanwhile, mineralization begins to seep into the body tissues and over centuries, results in a perfectly preserved animal or plant. Lava also forms fossils, but what is formed is not the actual creature or plant, but an impression of it. The hot lava envelopes the object (for example, a tree) and the intense heat burns the original tree, but if the temperature of the lava was just right, it was plastic enough to retain the impression of the tree. Something like making a plaster cast of something. What you are left with is a negative impression, and if you pour casting material, wax, or anything else into the mold, what comes out will be a replica of whatever was trapped in there in the first place.
There is a third fossil maker, and that is intense cold. When there has been a violent cold snap, sometimes an animal or a plant will be caught in the old, freeze to death, and if the cold continues (as in climate changes, or when glaciers are forming) the animal or plant will be preserved in its exact form, won't deteriorate, and will last for millenia.

Answer 3

That's stupid to say for the person above who said, "If you don't know don't ask", because that is exactly what this place is for.


There are several ways in which a fossil may be formed. They are
1) permineralization
Permineralization occurs when the pores of the plant or animal remains are impregnated by minerals. When this happens, the original shape of the object is not changed.
Petrifaction is a type of permineralization. It occurs when the organic matter is completely replaced by minerals and the fossil turns to stone. Petrified wood is a common example of this.

2) molds and casts
Casts and molds are types of fossils where the physical characteristics of organisms have been impressed onto rocks. This happened when organisms became buried or trapped in mud, clay, or other materials which hardened around them. The bodies decayed, leaving molds of the organism.
There are two types of molds: external and internal. The external is created when the bodies dissolve and leave empty cavities imprinted with the external details of the organisms. Internal molds form from hollowed structures when the interior of an organism is filled with inorganic material. When the shell deteriorates, an impression of the interior is left.


3) impressions
Impressions are two dimensional imprints of an organism which contain no organic matter. Impressions may be of plants or animals, or of tracks or footprints left by organisms. Most impressions are found in fine-grained sediment such as clay or silt. Impressions are formed when the soft mud or sediment in which they are made hardens into stone.
Impressions show pores and veins in plants and the skeletons of animals. The footprints and trails also provide information, such as the manner in which they moved or the size, of animals that are now extinct.


4) whole organism preservation.
There are few whole organism preservations. Most fossils consist of only parts of an organism, such as bones, shells, teeth, or footprints.
Very rarely are entire plants preserved as fossils. But, occasionally, trunks of trees were preserved when they were buried under mud containing volcanic ash. These groups of trees became petrified forests.
Some of the best-known whole fossils are eggs of dinosaurs, small reptiles, and birds. These usually come from animals which laid their eggs in lowlands where mud, silt, or other sediment covered the eggs.
The La Brea tar pits provide excellent examples of fossils which are of the whole organism. Numerous examples of organisms have been preserved there by asphalt, which preserves only the hard parts of the organisms. Bones, complete skeletons, insects, leaves, and flowers have been reclaimed from this site.
Wax, a infinitesimal part of the formation of fossils, is, however, an excellent preservative. It preserves all parts of the organism, not just the hard parts.
A unique type of fossilization is desiccation, or mummification. Bones and tissues of organisms are preserved, even keeping their natural colors. Desiccation occurs in areas void of moisture, such as the desert or in a dry cave. Dehydration occurs and the entire organism is preserved.
Freezing preserves a fossil of the highest quality. It preserves the organism with little alteration to the chemical composition. The temperature prevents little, if any, change to the organism.

Answer 4

A fossil is not soft tissue and the body does decay. Is it only hard matter like bone that becomes fossil.

Answer 5

Often they are either buried , submerged or frozen when they die. This prevents parisites and bacteria from decaying the bodies. Depending on the situation they may be either dried out and mummified or the cells may be saturated with minerals turning them to stone.

Answer 6

if you don't know don't ask