Dark-taxa
Guides
Sciaroidea
Fungus Gnats and Gall Midges
Sciaroidea is a superfamily of nematoceran flies in the infraorder Bibionomorpha, comprising approximately 16 families and over 15,000 described species. The group includes fungus gnats, gall midges, and related families, with larvae predominantly associated with fungi, dead wood, and soil. Fennoscandia represents a major biodiversity hotspot for this group, harboring roughly 1,000 species—about 83% of Europe's total. Despite substantial DNA barcoding efforts yielding over 56,000 barcode index numbers (BINs), only 5% currently have scientific names assigned, indicating vast undescribed diversity.
Undescribed
undescribed taxon, undescribed species
An undescribed taxon refers to any organism that has been discovered but not yet formally described and named according to established nomenclatural codes. These taxa lack official scientific names, though temporary informal designations are commonly used in practice. The phenomenon spans all major organismal groups, with particularly high prevalence in insects, fungi, and tropical invertebrates. Modern molecular techniques have dramatically accelerated discovery of undescribed diversity, revealing cryptic species that appear morphologically identical but are genetically distinct. The interval between discovery and formal description averages 13–21 years, creating a substantial backlog known as the 'taxonomic impediment.'