Classification Helper

Taxon Helper Image
NBII Program

Taxonomy (from Greek taxis meaning arrangement or division and nomos meaning law) is the science of classification according to a pre-determined system, with the resulting catalog used to provide a conceptual framework for discussion, analysis, or information retrieval. In theory, the development of a good taxonomy takes into account the importance of separating elements of a group (taxon) into subgroups (taxa) that are mutually exclusive, unambiguous, and taken together, include all possibilities. In practice, a good taxonomy should be simple, easy to remember, and easy to use.

Taxonomy & Systematics

Systematist observing Giant Flatsedge (Cyperus giganteus) in Southern Paraguay NBII Digital Image Library

Biological systematics is considered to be the study of the diversity of life on the planet earth, both past and present, and the relationships among living things through time. Systematics, is used to understand the evolutionary history of life on earth. 

Systematics is often used synonymously with "taxonomy" and scientific classification." However, taxonomy is the describing, identifying, classifying, and naming of organisms.  Classification is focused on categorizing organisms within specific groups that show their relationships to other organisms. 

Systematics uses taxonomy as a means to understand organisms, as nothing about an organism's relationships with other living things can be understood without it first being properly studied and described in sufficient detail to identify and classify it correctly. Scientific classifications are aids in recording and reporting information to other scientists and to laymen.

A scientist who specializes in systematics is called a systematist.   A systematist must be able to use existing classification systems to insure proper identification and classification of species. 

This Systematics section of the NBII provides users with access to sites that provide biological names of organisms and their classification that shows the evolutionary relationship among species. 

Integrated Taxonomic Information System (ITIS)

Integrated Taxonomic Information System website image
NBII Program

The ITIS is the result of a partnership of federal agencies formed to satisfy their mutual needs for scientifically credible taxonomic information. Since its inception, ITIS has gained valuable new partners and undergone a name change; ITIS now stands for the Integrated Taxonomic Information System.

ITIS partners include:

  • Department of Commerce

    • National Oceanic and Atmospheric Administration (NOAA)

  • Department of Interior (DOI)

    • Geological Survey (USGS)

  • Environmental Protection Agency (EPA)

  • Department of Agriculture (USDA)

    • Agriculture Research Service (ARS)

    • Natural Resources Conservation Service (NRCS)

  • Smithsonian Institution

    • National Museum of Natural History (NMNH)

For all of your taxonomic needs, please visit ITIS at:

The NBII Program is administered by the Biological Informatics Program of the U.S. Geological Survey
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