Which of the following is NOT an animal phylum?

Plantae is the correct answer because it is the taxonomic group that encompasses all plants, not animals. In biological classification, animal phyla include Porifera (sponges), Chordata (which includes vertebrates such as mammals, birds, reptiles, amphibians, and fish), and Echinodermata (which includes starfish, sea urchins, and sea cucumbers). Each of these groups represents a different branch of the animal kingdom, distinguished by unique body plans and characteristics. In contrast, Plantae represents a completely separate kingdom of living organisms that photosynthesize and typically have cell walls made of cellulose. This distinction helps clarify the organization of life on Earth into kingdoms, emphasizing the fundamental differences between animals and plants.