or animals outside the protostome/deuterostome split, including cnidarians and sponges.

The majority of animal species are invertebrates; one estimate puts the figure at 97%. Many invertebrate taxa have a greater number and diversity of species than the entire subphylum of Vertebrata. Invertebrates vary widely in size, from 10 um (0.0004 in) myxozoans to the 9-10