Biofacies interpretation of Star Peak and partly equivalent basinal conodonts is based upon sedimentologically and paleontologically determined lithofacies relationships as well as a regional paleogeographic model.

Late Spathian transgression initiated Star Peak sedimentation. Deep shelf conditions represented by the lower member of the Prida Formation supported an abundant neospathodid fauna ( Neospathodus homeriand N. triangularis) succeeded by a neogondolellid fauna ( Neogondolella jubataand N. timorensis). At the same time, restricted shallow marine waters to the east were sparsely populated by neogondolellids (Tobin and Dixie Valley Formations). During the Anisian, deep shelf conditions characterized all of Star Peak deposition (Fossil Hill Member). Conodont distribution was fairly uniform and again dominated by neogondolellids ( N. regale, N. bulgarica, N. shoshonensis, N. constricta, N. naviculaand N. mombergensis). Ladinian progradation of a carbonate platform across the shelf resulted in a diversification of environments. None was hospitable to conodonts. The platform slope lithology (upper Prida) is apparently barren. Rare neogondolellids occur in restricted shallow marine deposits of the Home Station Member (Augusta Mountain Formation) but are absent from the supratidal Panther Canyon Member. Carinella mungoensisis abundant only in well-bedded open marine sediments within the predominantly massive Smelser Pass Member.

Shelf sedimentation was interrupted in the Karnian. Meanwhile, late Karnian oceanic basin sedimentation to the west (Jackson Mountains) was characterized by N. polygnathiformisand, into the Norian, Epigondolella ?abneptissubsp.A. Resumption of shelf sedimentation occurred during the early Norian (Cane Spring Formation). The sparse conodont fauna consists mainly of E. abneptissubsp.B.