What does phylum mean?
A phylum is one of the principal ranks in the scientific classification of living organisms. It sits between a kingdom and a class, bringing together groups of organisms with broad biological similarities and shared ancestry. For example, the animal phylum Chordata includes vertebrates as well as several groups of invertebrates characterized by a notochord at some stage of development. The term comes from the Greek phylon, meaning “tribe,” “race,” or “kind,” which reflects its historical use for large divisions of the natural world. In modern biology, phyla are recognized within the broader framework of taxonomy, alongside kingdoms, classes, orders, families, genera, and species. Outside biology, the word can occasionally be used figuratively to describe a major branch or division, but its primary meaning is firmly taxonomic and is especially common in discussions of biodiversity, evolution, and the structure of life.
nounA major taxonomic group in the classification of organisms, ranking below a kingdom and above a class. A phylum groups related classes and may contain a very large number of species.
- A major taxonomic rank, below kingdom and above class, used in the classification of organisms.
"The vertebrates constitute a phylum that includes mammals, birds, reptiles, amphibians, and fish."
"Mollusca is a large animal phylum that includes octopuses, snails, and squid."
"The discovery of a new species can prompt scientists to reconsider how it fits within its phylum."
The standard plural form is phyla, though phylums is also used.
"The museum's collection represents organisms from many different phyla."
From a Greek word meaning “tribe” or “race,” a phylum is literally a large biological clan organized by shared ancestry.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does phylum come from?
The word phylum comes from Greek phylon, meaning “tribe,” “race,” or “kind,” a term associated with the classification of organisms into broad groups. It entered English in the 19th century as a biological taxonomic rank, adapted from forms such as the French phylum. The root also appears in related scientific terms including phylogeny, phylogenesis, and phyletic, all of which concern biological groups or their evolutionary relationships.
Related word forms
How phylum is actually used
In biology, the term is used in a formal classificatory sense. It can also be used metaphorically for a broad division within a field, though that use is less common.
Easily confused with phylum
A phylum ranks below a kingdom and above a class in the standard biological classification hierarchy.
A clade is a group defined by shared ancestry, whereas a phylum is a formal taxonomic rank in biological classification.