There are
two main groups of animals: vertebrates and invertebrates.
Vertebrates are a subgroup of the Phylum Cordata, or animals
that have a spinal chord. These include fish, amphibians,
reptiles, birds and mammals. You might not think it, but
invertebrates, or animals without a spinal chord, make up
most of the animal kingdom. These include sponges,
jellyfish, worms, arthropods (insects, shrimp, spiders),
mollusks (snails, clams, octopuses), and echinoderms (sea
urchins, sea stars).