Pronunciation: a-po-MOR-fik

Etymology: Apomorphic is derived from two Greek roots that mean from or off (apo, από) and form (morfi, μορφή). The reference is to a character or state that is removed from the primitive condition. That is, it is a derived condition.

An apomorphic character is one that is “advanced” or derived from a primitive state.

Consider the example of Urodacus yaschenkoi (an australian scorpion) below. The first walking leg has the more primitive or plesiomorphic state of both claws being almost equal in size. The fourth walking leg, however, has a derived state in which the first claw is greatly enlarged and the second claw is reduced.

By Jack R. Holt. Last revised: 01/02/2009