Class (biology)

The hierarchy of scientific classification

A class is a rank used in the biological taxonomy of all organisms. Each class is split into orders. There are multiple classes in each phylum. Mammals, for example, are one of several classes within the Vertebrates, and are subdivided into Monotremes, Marsupials, and Eutheria.

Ranks below class and above order are often used. Then the sequence is:

  • Class
  • Subclass
  • Infraclass
  • Order