A succession of unusually rich, well-preserved and diversified Carnian-Norian benthic foraminiferal assemblages has been found in an isolated limestone remnant of the Panthalassa Ocean (Black Marble Quarry, Wallowa terrane, Oregon). Foraminifers, including about 75% of well-known Tethyan species, show there a comparable stratigraphic distribution with Tethyan localities. The apparent synchronous occurrence of similar forms on both sides of the Panthalassa Ocean highlights the strong potential of foraminifers as stratigraphic tools for the Upper Triassic global correlations.