THALAMID SPONGES FROM THE UPPER TRIASSIC (NORIAN-RHAETIAN) NAYBAND FORMATION NEAR WALI-ABAD, SE ABADEH, CENTRAL IRAN(CONTRIBUTION TO TRIASSIC PALEONTOLOGY OF IRAN 4)

Abstract

An association of thalamid sponges including Amblysiphonella, Nevadathalamia, Stylothalamia, and Neoguadalupia, with the hexactinellid Casearia is described from the Upper Triassic (Norian-Rhaetian) Nayband Formation of Hambast-Mts. near the small town of Wali-Abad (Abadeh region, central Iran). These Norian-Rhaetian (Neoguadalupia, Amblysiphonella, Nevadathalamia) and Liassic (Stylothalamia columnaris Le Maitre) thalamid sponge assemblages are exceptional associations, not previously reported from Iran nor from other localities in the world. The microfacies and organism associations in the sponge-bearing carbonates is discussed. Differences of macro- and microfaunal composition, as well as flora, support the recognition of Kristan-Tollmann et al. to classify the Nayband Formation in the Abadeh region as of a distinct unit, termed the "Wali-Abad-Faziesregion". Following thalamid sponge species are described as new: Nevadathalamia waliabadensis n. sp. and Stylothalamia hambastensis n. sp.