There are two main types of unilineal descent systems, patrilineal and matrilineal. A patrilineal descent system is one in which an individual's kin group, or clan membership, is traced through men. Making it easy to remember, patrilineal descent systems trace through the papas.This is the most common form of unilineal descent. A matrilineal descent system traces descent through the women of the clan.pposite of a patrilineal descent system is a matrilineal descent system, or a system of descent in which an individual's kin membership is traced through women. Again oversimplifying with some alliteration, it's one in which family descent is traced through the mamas!