Basal
'Basal' is a term in biology for 'primitive' or 'ancestral'. Basal is preferred because it is neutral and non-judgmental. This terminology came into use with cladistics. The term is used in evolution and classification to mean the group which gave rise to later forms. It is a term which works at any level: a basal species gives rise to derived species, and a basal group gives rise to derived groups.