Feature geometry and cooccurrence restrictions

Recent work by Clements (1985), Sagey (1986), Steriade (1987a) and others has shown clearly that distinctive features are hierarchically organised, and that the hierarchy includes a Place of Articulation constituent. Proposals differ, however, as to the organisation below this Place node. Clements (1985) suggests that there is a Secondary Place node dominating the vowel features, but that [anterior], [coronal] and [distributed] are directly dominated by the Place node itself. Sagey (1986) has argued that there are distinct Articulator nodes, Labial, Coronal and Dorsal, each of which dominates certain binary features, respectively [round]; [anterior] and [distributed]; and [high], [back] and [low]. Dorsal is thus present for both velar consonants and vowels. Steriade (1987a) modifies the Sagey model by adding a Velar node for velar consonants, distinct from the Dorsal node for vowels.