During Ocean Drilling Program Leg 122, Upper Triassic sediments were recovered at four sites (Sites 759, 760, 761, and 764) on the Wombat Plateau, a small horst on the northern margin of the Exmouth Plateau. Biostratigraphic results vary at each site, because of environment changes from prodeltaic in the late Carnian to marginal-marine and fluvial non marine in the Norian, and finally to reefal and mudftat in the Rhaetian. Sediments from these sites have been examined for calcareous nannofossils, dinoflagellates, foraminifers, ostracodes, radiolarians, and spores and pollen. The biostratigraphy of the Carnian-Norian sequence is based primarily on organic microfossils, since the rare occurrence of calcareous microfossils minimizes the stratigraphic potential of those groups. The carbonates of the overlying Rhaetian sequence, however, contain rich foraminifers, ostracodes, and calcareous nannofossil assemblages. Siliceous microfossils in the Carnian to Rhaetian sequence are nearly absent, except for rare fragments of radiolarians. The near-continuous late Carnian to Rhaetian sequence recovered on the Wombat Plateau allows us to compile a biostratigraphic framework for different fossil groups.