The family acrocrinidae (Echinodermata, Crinoidea) and the carboniferous-permian boundary in the Neopaleozoic sequences of Tepuel-Genoa basin (Chubut, Argentina)

THE FAMILY ACROCRINIDAE (ECHINODERMATA, CRINOIDEA) AND THE CARBONIFEROUS-PERMIAN BOUNDARY IN THE NEOPALEOZOIC SEQUENCES OF TEPUEL-GENOA BASIN (CHUBUT, ARGENTINA). Acrocrinida from the Carboniferous of West Central Patagonia are described for the first time in South America. One species is assigned to Denariocrinus Webster and Jell, previously known from the Neerkol Formation, Australia; and two are assigned to new genera: Sueroacrocrinus torresverdinei gen. et sp. nov. and Patagononcrocrinus giganteus gen. et sp. nov. These crinoids were found in Sierra de Tepuel (Pampa de Tepuel Formation) and sierra de Langui (n) over tilde eo (Las Salinas Formation, LS2 Member). They are comparable with acrocrinids from Australia. Faunal relationships with Australia are so striking, as similarly shown by bryozoans, that they allow assignment of the fossiliferous levels to the Late Carboniferous.