Living Fossil in Biology Explained Clearly

Fossils are remnants of living beings that survived for a long period of time. These form evidence for the evolution of all civilizations. Living fossils are the ones that are used to study and describe the similarities and differences between the present and the past. This means that, through Living Fossils, you can portray a relationship between the living organisms and the fossils of extinct specimens.

What is a Fossil?

Fossils are the parts of living things that cannot be degraded over time, so they remain as traces in the environment. These naturally get buried in rocks and are preserved in the Earth’s crust. The word "fossil" comes from the Latin word "fossus," which means "dug up." These fossils are very helpful in studying organisms that are not actually present in the environment in the present day. Fossils may include any remnants of living organisms such as hair, imprints of animals on stones, shells, bones, coal, exoskeletons, petrified wood, and DNA remnants.

Different Types of Fossils

Fossils can be broadly divided into two categories:

1. One is the actual body parts of the organism that are fossilised over time. This can include bones, claws, teeth, skin, embryos, etc.

2. The other types are fossilised traces, which include the traces left by these organisms and cannot be considered actual body parts. These are also called ichno-fossils and can include footprints, dung, nests, or tooth marks. These traces can be useful in recording and tracking the movements and behaviours of these living organisms.
   
   

There are Six Different Types of Fossils, as Described Below:

1. Direct Fossils: When fossils are formed from the burial of an ancient living organism, their remains in the form of skeletons get reserved due to sedimentation. This type of fossil is called a direct fossil.

2. Ichno-Fossils: Fossils that are preserved in the form of traces such as nests, footprints, and faeces of ancient living organisms are called Ichnofossils. These fossils are not the actual body parts of the organism but only traces.

3. Chemo-Fossils: The fossils made by the chemicals left by the earlier life forms are known as chemo-fossils. These are the biological remnants or signals that can be traced to the past.

4. Resin Fossils: Fossils made up of amber with organisms trapped inside them are known as resin fossils. They have been preserved in these resins or ambers for millions of years and can be formed in the form of bacteria, fungi, or insects.

5. Living Fossils: These are fossils that have remnants of organisms that have only been identified through fossil records. These are essential for studying evolution and forming a tie between the present and the past. It is a term used for formerly undiscovered life forms.

6. Body Fossils: These are the fossils that are found in the hard parts of the living organism. This may include bones, claws, and teeth.

What is a Living Fossil?

Living fossils are the remnants of organisms that have been identified through fossil records only. These are essential for studying evolution, and they form a tie between the present and the past. The name “living fossils” is used for formerly undiscovered life forms. By assessing living fossils, a common descent for various living species can be pinpointed and studied. This can be done by comparing the various similarities and differences between the present living and fossil creatures.

According to Charles Darwin’s theory of evolution, all living fossils have evolved in some way or the other and are existing in some form. Changing ecosystems, increasing and falling temperatures and other changes in air composition and circumstances have all forced living species to adapt.

These organisms have adapted to their environmental restrictions, reaching a peak of competence in surroundings that consistently reinforce certain physicality. Since certain fossils reveal no similar traits, it is clear that the species existed. These extinct animals serve as a stark warning to a world that is rapidly losing other live species.

Living Fossil Examples

The dome of the examples of living fossils is given below, with a division of organisms according to the number of cells they bear.

1. Unicellular Organisms- Bacteria, Algae, and Protozoa.

Unicellular organisms are the earliest living things that were present as life forms on this planet. These include bacteria, algae, cyanobacteria, etc. These are organisms that carry out complex chemical processes and can survive the harshest environments. Cyanobacteria is the oldest living fossil and emerged as early as 3.5 billion years ago. These bacteria are still the most successful group of organisms present on Earth, and so their study can provide us with the most ancient records of life that were present on this planet.

2. Multicellular Organisms – Animals and Plants.

Single-celled organisms developed into multicellular organisms and can be studied as a course of evolution as well.

The comb jelly, which is a multicellular organism, first emerged 700 million years ago and is older than most rock fossils present. They have been useful in studying evolution and forming a trajectory of development. Another example of a living fossil animal is the horseshoe crabs. Their existence is dated back to 450 million years ago and they are known to resemble Crustaceans.

According to the new discoveries, Wollemi pine is known as the most popular living fossil plant or tree and is around 200 million years old. It is found that the same species as this tree is found in Australia.

Conclusion

This article gives an insight into the mesmerizing world of living fossils, their examples, and the different names of living fossils. It also talks about different types of living fossils and how they are made. These are made of both unicellular and multicellular organisms.