Aristotle classified animals according to their habitat. Aristotle is the first documented individual to introduce a concept of the classification of organisms. In his system of classification, all living things are divided into two classes – plants and animals.
Basis of Classification
The history of biological classification began with Aristotle, the Greek philosopher, who is often called the father of biological classification. He explained animal classification based on their habitat, i.e., air, water and land. He was the first person to acknowledge the need for groups and group names in the study of the animal kingdom.
Later, biologists began to work on the classification of living organisms based on their characteristics. A group of organisms is similar enough to be classified together by certain characteristics. Characteristics are the appearance/form and behaviour/function of something. These characteristics decide which organism will be placed in which group.