Taxonomic Hierarchy

Over several millions of years ago, there was a huge number of species evolved on this planet and to make the research easier, different scientist worked on the classification based on the fundamental assumption. Initially, the classification was started by differentiating living and nonliving things. Based on the certain features, similarity and dissimilarity the biological classification began among the living organisms.

According to the history of biological classification, Aristotle, a Greek philosopher classified different animals based on the habitat, characteristics and lot more. Later, Swedish botanist, Carolus Linnaeus introduced Taxonomic Hierarchy Categories during the 18th Century, and his system of classification is still followed today globally.

Here, let us know more about Taxonomy and its Hierarchy In Biological Classification

What is Taxonomy?

Taxonomy is a branch of Biology that refers to the process of naming and classifying different living species into their kingdoms based on their similarities and differences. The word Taxonomy is generally derived from a Greek word – “taxis”, meaning arrangement or division, and “nomos”, meaning method.

Also,read about Taxonomy .

Taxonomic Hierarchy in Biological Classification

The word taxon or taxa generally refers to a group of living organisms (animals,birds,plants) that are classified as a unit.
The Taxonomic hierarchy is the process of arranging various groups, class and other categories into successive levels of the biological classification in a sequence either in a decreasing or increasing order from kingdom to species and vice versa. Each of this level of the hierarchy is called the taxonomic category or rank. In this system of classification, Kingdom is always ranked high followed by division, class, order, family, genus, and species which is always ranked the lowest in the Hierarchy.

Also,read about Basis of Biological Classification.

Taxonomic Hierarchy In Biological Classification

Taxonomic Hierarchy Categories were introduced by Linnaeus, therefore it is also known as a Linnaean hierarchy.

Let’s understand this concept with an example.

Consider a group of different birds. All of them show general and similar characteristics like beaks, feathers, wings and flight. Thus, based on these common characteristics, they can be classified into a taxonomic category.

The Taxonomic Classification System

The study of taxonomy has led to the taxonomic categories – Kingdom, phylum, class, order, family, genus, and species. Now let us see how all the organisms are classified into the hierarchy.


It is the lowest level of classification and shows the high level of similarities among the organisms. One species can be distinguished from other closely related species based on distinct differences in morphology.
Let us look at an example:
Plasmodium vivax and Plasmodium falciparum – Both are malaria-causing parasites but have different effects on a patient. Plasmodium is the name of the genus and has a number of species which show distinct morphological characteristics.


This taxonomic group comprises several species which have similar characteristics but different from that of species from another genus.
Considering the same example of Plasmodium, it is a genius with multiple species which are similar to each other and differs from the species of another genus.


This category of taxonomy includes various genus which shares some similarities among themselves. However, the number of similarities decrease compared to species and genus.
For instance, the genus of tiger, leopard, lion, i.e., Panthera and the genus of cats i.e., Felis are grouped together in the family Felidae.


The classification which begins with the order has fewer comparisons as an effect, they are grouped based on aggregates of characteristics. A group of families showing somewhat few similarities forms an order.

For example, the order of carnivores i.e., Carnivore includes families like Felidae and Canidae.


A group of Orders which share a few similarities forms a Class.
For example- Orders of primates and carnivores are grouped together in the Class of mammals.


This is the next level of classification was along a number of Classes are clubbed up to form one Phylum.
For Example – Aves, fishes, reptiles, mammals, and amphibians combined to form the Phylum Chordata or phylum of Vertebrates.


The kingdom is the highest level of classification, which is divided into subgroups at various levels. There are 5 kingdoms in taxonomy, namely Animalia, Plantae, Fungi, Protista, and Monera.
Also,read about Five Kingdom Classification

Learn more about taxonomy, its Hierarchy, examples and other related topics @ BYJU’S Biology

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