Classification History



The earliest known system of classification is that of Aristotle, who attempted in the 4th cent. B.C. to group animals according to such criteria as mode of reproduction and possession or lack of red blood.

Augustus Quirinus Rivinus


in his classification of plants based on the characters of the flower, introduced the category of order (corresponding to the "higher" genera of John Ray and Andrea Caesalpino). He was the first to abolish the ancient division of plants into herbs and trees and insisted that the true method of division should be based on the parts of the fructification alone. Rivinus extensively used dichotomous keys to define both orders and genera.

Carolus Linnaeus

18th Century.

He divided all animals into six classes: Mammalia, Aves, Amphibia (including reptiles), Pisces, Insecta (Arthropoda), and Vermes (other invertebrates). He divided living things into one of two "kingdoms"-plant and animal kingdoms. He divided each of the kingdoms into smaller groups called "genera" (plural of "genus"). He divided each genera into smaller groups called "species." He 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.)

Ernst Haeckel


he described and named thousands of new species. He also proposed the animal kingdom "Protista." It consisted of of mostly unicellular organisms that did not fit into other kingdoms.

Herbert Copeland


He was an American Biologist who contributed to the animal kingdom by his proposal of the the fourth animal kingdom, Monera. This consisted of unicellular organisms without a nucleus such as bacteria.

Robert Whittaker


He was the first to propose the five-kingdom taxomic classification of the worlds biota into the Animalia, Plantae, Fungi, Protista, and Monera in 1959.

Thomas Cavalier


He proposed a new kingdom of life, the Chromista. This is a eukaryotic subgroup that can be treated as a separate kingdom or can be included in Protista.