superclade

A superclade is an informal term used in phylogenetics to denote a very large monophyletic group that encompasses multiple subordinate clades that share a common ancestor. It is not a formal taxonomic rank in standard nomenclature. The designation is primarily descriptive, applied when researchers want to emphasize broad evolutionary relationships that cut across conventional ranks such as phylum or class. Because different phylogenetic analyses can yield different trees, the exact membership and boundaries of a superclade are not fixed and may vary between studies.

In practice, the term superclade is used to discuss macroevolutionary patterns, to compare major lineages, or to summarize results where the internal structure is too detailed or contentious. It contrasts with formal clades that have defined names, while still relying on the principle of monophyly—the most recent common ancestor and all its descendants.

Examples of usage vary by author and field. In discussions of eukaryotic evolution, Opisthokonta is sometimes described as a deep superclade that contains Fungi and Metazoa. In animal phylogeny, broad divisions such as Protostomia and Deuterostomia are sometimes treated as superclades to highlight their major split, even though they are themselves clades within Bilateria. The term thus serves as a flexible shorthand for large-scale evolutionary relationships rather than a fixed taxonomic category.