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Why do zoologists use phylum while botanists often use division?

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Group of fallow deer (Dama dama) stags with large, palmate antlers standing alert in a green summer field. — Animal The fallow deer (*Dama dama*) has been introduced in many areas ever since the Neolithic Period.

In biological taxonomy, the terms phylum and division are used as equivalent ranks in the hierarchy of classification, representing the level below kingdom and above class.12

The use of these distinct terms is primarily a matter of historical convention within the respective fields of zoology and botany. Zoologists traditionally use the term phylum to categorize animals, while botanists traditionally use division to categorize plants.12

This dual terminology can create ambiguity when classifying organisms in the kingdom Protista, which contains groups of interest to both disciplines. In such cases, the choice of term often follows the prevailing usage of the researcher: phylum is typically applied to animal-like protozoa, while division is used for plantlike protistan groups. Ultimately, these labels are not defined by specific, universal taxonomic characters but are maintained due to the unique taxonomic histories of each group of living things.21