Undescribed species: A species which has never received a species name in a formal scientific publication for which a very detailed description (and comparison with all known closely-related species) is required. It is very unusual to discover an undescribed species among birds or mammals anywhere in the world, but enormous numbers of undescribed species of insects and nematodes exist in the tropics (and considerable numbers even in Florida). Each undescribed species must receive a species name before information about it can be added to the scientific literature. See also taxonomy and identification.