What is division in zoology?

In zoology, division refers to an optional taxonomic rank used to classify animals. It sits below the infraclass and above the cohort.

Here's a more detailed explanation:

• Taxonomic Rank: Division is a specific level within the hierarchical system used to classify living organisms, including animals. This system helps organize and understand the relationships between different species.

• Hierarchical Position: It is positioned in the following manner:

  • Class
    • Subclass
      • Infraclass
        • Division (Optional)
          • Cohort
            • Order
              • Etc.

• Optional Rank: The key point is that the "division" rank is optional. It is not always used in every classification scheme. Zoologists may choose to use it when they find it helpful to further refine the classification within a particular group of animals.

• Example: A classic example involves the classification of teleost fishes. They are sometimes grouped into a Division Teleostei within the Class Actinopterygii (ray-finned fishes). This division helps to distinguish the teleosts (a very large and diverse group of bony fishes) from other ray-finned fishes.

In essence, division is an extra layer of organization within the animal kingdom's classification system, employed to further categorize groups when deemed necessary.