I present an analysis of a typologically unusual pattern of coordination reduction in Yidiny, a Pama-Nyungan language (Dixon 1977). Yidiny shows two dissociated patterns of syntactic ergativity, one that is dependent upon surface morphological features and another indifferent to them. Because within a single language syntactically ergative phenomena can dissociate, there must be at least two possible, though related, routes to syntactic ergativity. I propose that syntactic ergativity can occur in a language either because of an operation yielding prominence of the internal argument of a transitive verb in the syntax, or because of the interaction of syntactic mechanisms with case-marking.The Coyote Papers are made available by the Arizona L...