Definition of synapomorphy
noun (plural synapomorphies)
Biology a characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants: the study of skulls of this primitive reptile has led to the discovery of numerous synapomorphies with turtles [mass noun] possession by two or more organisms of a characteristic inherited exclusively from their common ancestor: synapomorphy delineates the relative status of particular features with respect to a specific evolutionary problem
