Types of Fossils

Fossils can be classified into different subgroups. Types of Fossils are:

Index Fossils

An Index Fossil is also known as a guide fossil. Fossils of any plant or animal preserved in the Earth’s rock record are used to determine a certain period of geologic time or habitat. An effective index fossil needs to be unique or easily identifiable, abundant, have a broad geographic distribution, and have a short time range. The best index fossils are widespread, common, and easy to recognize at the species level. The boundaries for the geologic time scale and the correlation of strata are determined by index fossils.

Trace Fossils

The majority of trace fossils are tracks and burrows, although they can also be coprolites (fossil excrement) and feeding imprints. Trace fossils are especially significant since they represent a data source that is not restricted to creatures with easily fossilized hard components and because they depict animal behavior. Trace fossils record an animal’s activities at a specific time and hence reveal the animal’s habitat. For instance, mudstone trace fossils of animal burrows indicate that the animal lived in a muddy environment.

Transitional Fossils

A transitional fossil is one that belongs to a species that possesses qualities from both its ancestor and its descendant species. These fossils are the remains of an organism that existed between the earliest known form of a species and the current species. Transitional species and fossils provide insight into an evolutionary process. As an example, it is commonly known that humans descended from primitive apes millions of years ago. Transitional fossils are said to depict intermediate forms of a species, which changed and accumulated adaptations slowly, making them evidence for evolution.

Microfossils

A microfossil is a tiny fossil that is often studied only under a microscope and can either be a whole tiny organism or a piece of a bigger organism. The tiny remains of bacteria, protists, fungi, animals, and plants are known as microfossils. Since they must be removed from rock samples in a specific way and viewed under a microscope, microfossils are a group of fossil remnants researched as a particular subject. The reason why microfossils are classified differently from other types of fossils is entirely due to their relatively small size and techniques of examination.

Amber Fossils 

Most trees release resin from their bark. When an organism, such as insects or even small animals like frogs and lizards, is caught in the resin, the process of fossilization occurs. When the tree is buried underground, the resin eventually becomes hard and transforms into amber. In addition to insects pollen and seeds can also turn into fossils if they are caught in resin. Inclusions are additional fossils found in fossil resin that were drawn into the resin’s sticky substrate. They include various types of animals, plants, fungi, and microbes. Animal inclusions are often tiny invertebrates, mostly arthropods like insects and spiders, and only a few are vertebrates like small lizards.

Body Fossils

Body fossils are those that are discovered on an organism’s hard body parts, such as its bones, claws, teeth, outer skin, or scales. The majority of fossils found globally are body fossils, which are created from the remnants of extinct animals and plants. The majority of fossilized body parts are composed of hard structures like teeth, bones, shells, or woody trunks, branches, and stems. Body fossils come in a variety of sizes, from tiny organisms that can barely be seen under a microscope to gigantic dinosaurs.

Molecular Fossils 

A molecular fossil is simply preserved organic material that has mostly decomposed or been turned into fossils. Molecular fossil is extremely delicate  Because it is built on the same chemical structures that made up the organism. This type of fossil is extremely vulnerable to degradation as chemical processes break the bonds holding the molecule together.

Trace Fossils

The majority of trace fossils are tracks and burrows, although they can also be coprolites (fossil excrement) and feeding imprints. Trace fossils are especially significant since they represent a data source that is not restricted to creatures with easily fossilized hard components and because they depict animal behavior. Trace fossils record an animal’s activities at a specific time and hence reveal the animal’s habitat. For instance, mudstone trace fossils of animal burrows indicate that the animal lived in a muddy environment.

Carbon Fossils

Carbonized fossils are found commonly around coal seams. The conversion of anything into carbon is referred to as carbonization. these remains of organisms were exposed to high pressure over time, such as when they were buried beneath sediments on the seafloor. Compression is the term for the action of forcing two or more things together while also reducing their size and volume. A number of its constituents, including hydrogen, nitrogen, and oxygen, are finally drained away after the remains are compressed. This results in the formation of a thin coating of carbon residue or film on a two-dimensional rock.

Pseudofossils

Pseudo fossils are inorganic remnants, imprints, or markings that could be mistaken for real Fossils. Pseudofossils may be misleading because some mineral deposits have the ability to resemble living organisms by producing what appear to be complex or well-organized structures. Pseudofossils resemble fossils or other types of fossilized life, as they are created by inorganic (non-living) processes.

A fossil is a preserved remnant, impression, or trace of an animal or plant from a past geologic age by some natural process. Just a small proportion of extinct species have been preserved as fossils, and often only those with a solid skeleton are capable of being preserved. A calcareous skeleton or shell is found in a large number of major groups of invertebrate creatures (e.g., corals, mollusks, brachiopods, and bryozoans).  The organic tissues can be preserved in a shell or bone that is buried soon after deposition, they eventually get petrified (transformed into a stone substance). In sedimentary rocks, unaltered hard pieces, such as the shells of clams or brachiopods, are abundantly available.