Holothurian sclerites from the Triassic of Jordan and their stratigraphic importance

Abstract. Holothurian selerites are some of the most stratigraphically important microfossils of the middle Triassic of Jordan. Stratigraphically and palaeogeographically important faunas have been obtained by dissolving Triassic carbonate rocks with a dilute acetic acid. The oldest forms, Acanthotheelia jordanica Sadeddin, Priscopedatus quadratus Kozur & Mostler, and Tetravirga perforata Mostler, occur in the Hisban Formation (Anisian) in the area of the northeast corner of the Dead Sea and Wadi Abu Oneiz. North of this area in Wadi Salit, Ladinian holothurian faunas are especially characterized by the mass occurrence of Schizotheelia jordanica and Schizotheelia multiporata Kozur & Sadeddin in the lower part of the section (Fassanian) and Theelia tubercula Kristan-Tollmann in the upper part (Longobardian). In spite of some differences, the Jordanian Middle Triassic holothurian faunas are similar to those from the Northern Alps and Germanic Basin, and the Himalayas. As yet, no holothurian selerites have been recovered from Jordanian Lower or Upper Triassic deposits.