Invertebrates do not have backbones or internal skeletons, but some have hard coverings. Invertebrates are weird and wonderful creatures that come in every shap

So much has to be crammed into today's biology courses that basic information on animal groups and their evolutionary origins is often left out. This is particu

Discusses what invertebrates are and how they are classified, and provides in-depth information about many specific invertebrates, such as insects, sponges, and

An introduction to the characteristics of the major groups of invertebrates and vertebrates.