Tree of Life Project
The Tree of Life Web Project: Animals
Extensive site that contains much information about the various animal phyla. Each phyla gives photos, common examples, scientific names and references. Collection of 1630 websites about bio-diversity.
Stanford University
Stanford University: Sea Urchins
A good overview from Stanford University of the structure and function of sea urchins. A useful place to start in your study of echinoderms.
Stanford University
Sea Urchin Images
Free, downloadable images on a variety of topics related to urchin development, anatomy and physiology. Useful for teaching, worksheets and reports.
Stanford University
Stanford University: Sea Urchin Natural History
Stanford University offers an excellent review of the biology and ecology of sea urchins. After reading the text, try the reproduction/survival game!