Animal Diversity Web (ADW) is an online database of animal natural history, distribution, classification, and conservation biology at the University of Michigan.

The Catalogue of Life provides critical species information on:
Synonymy enabling the effective referral of alternative species names to an accepted name.
Higher taxa within which a species is clustered.
Distribution identifying the global regions from which a species is known.

Here you will find authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world. ITIS is a partnership of U.S., Canadian, and Mexican agencies (ITIS-North America); other organizations; and taxonomic specialists. ITIS is also a partner of Species 2000 and the Global Biodiversity Information Facility (GBIF). The ITIS and Species 2000 Catalogue of Life (CoL) partnership provides the taxonomic backbone to the Encyclopedia of Life (EOL).

The Taxonomy Database is a curated classification and nomenclature for all of the organisms in the public sequence databases. This currently represents about 10% of the described species of life on the planet.