A verbal °marker is a perfective marker if it indicates °bounded aspectual reference and if it can be used for a sequence of successive events in a narrative.
"Perfectives signal that the situation is viewed as bounded temporally. Perfective is the aspect used for narrating sequences of discrete events in which the situation is reported for its own sake, independent of its relevance to other situations (Hopper 1982). It is thus often used to refer to situations that occurred in the past. Anterior differs from perfective in that it would not be marked on several verbs in succession that are reporting a sequence of events but would only be used to show that some action is prior to the others in the narrative (Givón 1982)." (Bybee et al. (1994: 54)