From the introduction to the Database:
Taxonomic coverage of the database includes not only all “true” starfish taxa but also the enigmatic and controversial concentricycloids, which have been included based on the taxonomic classification of Mah (2006). Although identification of taxa with fossil members is indicated, most have not yet been included. Some fossil taxa may be entered in the future for completeness but fossil groups were not a primary objective for the WoRMS database.
The core of the World Asteroidea Database (WAD) is derived from the "Asteroid Names List" developed primarily by Ailsa M. Clark. However the WAD is complimented by numerous other echinoderm compendia (e.g., Clark & Downey's Starfishes of the Atlantic, Rowe & Gate's Zoological Catalogue of Australia, etc) and will eventually include all subsequent taxonomic changes and newly described taxa.