Definition: A taxon is Data Deficient when there is inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status. A taxon in this category may be well studied, and its biology well known, but appropriate data on abundance and/or distribution are lacking. Data Deficient is therefore
not a category of threat. Listing of taxa in this category indicates that more information is
required and acknowledges the possibility that future research will show that threatened
classification is appropriate. It is important to make positive use of whatever data are available. In many cases great care should be exercised in choosing between DD and a threatened status. If the range of a taxon is suspected to be relatively circumscribed, and a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified.
Definition: A taxon is Least Concern when it has been evaluated against the criteria and does not
qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread
and abundant taxa are included in this category.
Definition: Component found in mineralized skeletal tissue, (a specialized form of biogenic tissue in which the extracellular matrix is mineralized, and which functions in mechanical and structural support.)