- subordinate to the phylum
- superordinate to the infraphylum.
Where convenient, subphyla in turn may be divided into infraphyla; in turn such an infraphylum also would be superordinate to any classes or superclasses in the hierarchy.
Not all fauna phyla are divided into subphyla. Those that are include:
- Arthropoda: divided into subphyla Trilobitomorpha, Chelicerata, Myriapoda, Hexapoda and Crustacea,
- Brachiopoda: divided into subphyla Linguliformea, Craniformea and Rhynchonelliformea,
- Chordata: divided into Tunicata, Cephalochordata, and its largest subphylum Vertebrata.