title: Ophiuroids discovered in the middle triassic hypersaline environment.
abstract: Echinoderms have long been considered to be one of the animal phyla that is strictly marine. However, there is growing evidence that some recent species may live in either brackish or hypersaline environments. Surprisingly, discoveries of fossil echinoderms in non-(open)marine paleoenvironments are lacking. In Wojkowice Quarry (Southern Poland), sediments of lowermost part of the Middle Triassic are exposed. In limestone layer with cellular structures and pseudomorphs after gypsum, two dense accumulations of articulated ophiuroids (Aspiduriella similis (Eck)) were documented. The sediments with ophiuroids were formed in environment of increased salinity waters as suggested by paleontological, sedimentological, petrographical and geochemical data. Discovery of Triassic hypersaline ophiuroids invalidates the paleontological assumption that fossil echinoderms are indicators of fully marine conditions. Thus caution needs to be taken when using fossil echinoderms in paleoenvironmental reconstructions.
authors.affiliation: Department of Palaeontology and Biostratigraphy, University of Silesia, Faculty of Earth Sciences, Sosnowiec, Poland. paleo.crinoids@poczta.fm
authors.forename: Mariusz A
authors.initials: MA
authors.lastname: Salamon
authors.forename: Robert
authors.initials: R
authors.lastname: Niedźwiedzki
authors.forename: Rafał
authors.initials: R
authors.lastname: Lach
authors.forename: Tomasz
authors.initials: T
authors.lastname: Brachaniec
authors.forename: Przemysław
authors.initials: P
authors.lastname: Gorzelak
mesh_terms: D000818:Animals; D004447:Echinodermata; D017753:Ecosystem; D005580:Fossils; D019015:Geologic Sediments; D010163:Paleontology; D011044:Poland; D054712:Salinity