a character traitunique to a particular unique to a particular taxon; Because autapomorphies do not provide information about the organism's phylogenetic relationships to other taxa, they are of no use in cladistics. However they still provide useful non-phylogenetic information about the species in question. Compare with apomorphy, plesiomorp [..]

an apomorphy possessed by a species or clade that is shared with no other species or clade.

An apomorphy unique to a single species.

    An apomorphy in a terminal taxon; diagnoses the terminal but is uninformative about relationships to other terminals; therefore of no use for cladistic tree-building.

a derived trait that is unique to a particular taxon