The Marine Upper Triassic Paleobiota from the Scheiblingbach Konservat-Lagerstätte in Austria

Abstract This contribution reports new data on the Upper TriassicScheiblingbach Konservat-Lagerstätte in the Northern Calcareous Alps of Styria. New fossil material was obtained and examined from bed-by-bed collections in the silicious Göstling Formation and the well-laminatedReingraben Formation. Over 4,602 new fossils of various marine taxa were collected within the fossiliferous layers from the early Carnian (Julian 2, Austrotrachyceras austriacum Zone). The assemblage comprises ammonoids ( Austrotrachyceras , Paratrachyceras , Carnites ), coleoids ( Mojsisovicsteuthis , Phragmoteuthis ), bivalves ( Peribositra , Halobia , div. indet taxa), gastropods (caenogastropods/heterobranchs), thylacocephalan arthropods ( Atropicaris ), branchiopods ( Euestheria ), rare coelacanth remains (scales) and actinopterygianfishes ( Peltopleurus ). Bromalites (coprolites and regurgitalites) produced by piscivorous actinopterygians and durophagousfishes complete the Scheiblingbachpaleobiota along with frequent plant remains ( Voltzia , div. indet plants). The Scheiblingbachpaleobiota in the normal marine Reifling Basin characterizes a fluctuating basinal environment with intermittent influx of freshwater, accompanied by the enhanced presence of land plants and colonization by abundant benthic halobiidbivalves. The nektic community is dominated by ammonoids, belemnoidsand actinopterygianfish. The prerequisites for preservation – calm and oxygendepleted conditions – prevailed at the seafloor of the Scheiblingbach Konservat-Lagerstätte during the deposition of black intermittent layers in the Göstling Formation and in the basal part of the Reingraben Formation. New in situ findings of benthic and nektic taxa highlight the great value of the additional Scheiblingbachpaleobiota in comparison to the well-known contemporaneous PolzbergPaleobiota and regarding the autochthonous deposition of the inhabitants within the paleohabitat in a Konservat-Lagerstätte . The fauna and flora from Scheiblingbach point to a carbonate platform decline, followed by warmer and wetter conditions during the Carnian Pluvial Episode, triggering the deposition of laminated sediments and forcing inhabitants to adapt.