Symplesiomorphy vs. Plesiomorphy

Symplesiomorphynoun

(cladistics) An ancestral trait shared by two or more taxa.

Symplesiomorphynoun

The possession by two or more organisms or taxa of a shared primitive or ancestral character not exclusive to or characteristic of them in particular; the shared character itself.

Plesiomorphynoun

(cladistics) A character state that is present in both outgroups and in the ancestors

Plesiomorphynoun

The state of being plesiomorphic; ancestral or primitive condition as compared to a later, derived character state. Also (as a count noun): an ancestral or plesiomorphic feature or trait.