Definition of "subphylum" []

• A taxonomic category of related organisms ranking between a phylum and a class. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Mammals are then grouped with the classes of other backboned animals, such as reptiles, into a "subphylum," Vertebrata, which is part of the "phylum" Chordata, containing all animals which have a nerve chord at some time in their life cycle."
• "Most members of the chordate phylum, those in the subphylum Vertebrata, replace the notochord with vertebrae (the backbone) later in development to support the pelvic and pectoral girdles (to which the front and hind limbs are attached) and to protect the spinal cord."
• "Representatives of only a part of just one subphylum, terrestrial vertebrates, were rescued."