ARISTOTLE - Aristotle was alive in the 4th century BC (384 to 322 BC) and was a Greek philosopher. He was the person to divide organisms to two groups- plants and animals and divided animals into blood and bloodless. He was also the one to divide the animals according to how they moved - walking, flying, or swimming ( land, air, or water ). His system was used in the 1600's.
CAROLUS LINNAEUS - In the 18th century a Swedish scientist, Carolus Linnaeus classified plants and animals according to similarities. He classified plants and animals and then divided the kingdoms into smaller groups called Genera. The Genera was then also divided into a group called species. This designed a system of naming organisms called binomial ("two names") nomenclature ("system of naming") which gave each organism 2 names - genus (plural = genera) and species (plural = species) names. The genus and species names would be similar to your first and last names. Genus is always capitalized while species is never capitalized. To be written correctly, the scientific name must be either underlined or written in italics. his classification system is still used today; however, we use a 5 kingdom system (instead of 2 kingdom system.)
Early classification systems grouped organisms as to whether they were beneficial or harmful. Another ancient classification systems recognised animal groups domestic animals, creeping animals, wild animals, flying animals, and sea animals.