Last updated 6 months ago
The major subgroups of animals are usually classified as phyla (singular: phylum). The higher classification of animals is still in flux, and scientists' opinions on which groups should be given phylum status change as new information about the structure of the animal tree of life becomes available. So you may see that some of the groups listed here as phyla are classified differently elsewhere. For example, the spiny-headed worms, Acanthocephala used to be treated as a phylum, but research has shown that this group is probably nested within the phylum Rotifera, so it will probably disappear from modern lists of animal phyla.
Follow the links below to find out more about each animal phylum. Species estimates are from:
Chapman, A. D. 2009. Numbers of Living Species in Australia and the World. 2nd edition. Australian Government, Department of the Environment, Water, Heritage and the Arts. Canberra, Australia.
Zhang, Z.-Q. 2011. Animal biodiversity: An introduction to higher-level classification and taxonomic richness. Zootaxa 3148: 7–12.