What is an phylum?

A phylum (/ˈfaɪləm/) is a taxonomic rank in the Linnaean system of biological classification. It is used to group related classes.

The phylum is the second highest rank in the Linnaean system, below the domain and above the class.

Some examples of phyla include:

- Porifera (sponges)

- Cnidaria (jellyfish, corals, and sea anemones)

- Platyhelminthes (flatworms)

- Nematoda (roundworms)

- Annelida (segmented worms)

- Mollusca (clams, snails, and octopuses)

- Arthropoda (insects, spiders, and crustaceans)

- Echinodermata (sea stars, sea urchins, and sand dollars)

- Chordata (fishes, amphibians, reptiles, birds, and mammals)