A

David

Darling

phylum

A phylum is a category in the hierarchy of animal classification ranking above class and below kingdom. Plural: phyla. Phylum names are written in Roman (ordinary) letters and begin with an initial capital letter; for example all animals with backbones (vertebrates) are members of the phylum Chordata. Some phyla are further subdivided into subphyla (subphylum). In plant classification, the analogous category is sometimes called division.