(Paleoanthropology) A later state of a character relative to its ancestral state.
An apomorphy is a new genetic characteristic common to a clade. Feathers are an apomorphy for birds.
(adj. apomorphic or apomorphous) A relatively derived or advanced or unique character state (cf. autapomorphy, synapomorphy, plesiomorphy, symplesiomorphy).
A derived character state; a new feature that arose during the course of evolution.
a character state which is unique to a single, terminal taxon. Example: among primates, complex grammar is an apomorphy of human beings. It is quite diagnostic of humans, but useless in determining phylogenetic relationships because it is not a shared, derived characteristic, or synapomorphy, of any larger group.