Macrofauna of the Carnian beds in the Mežica area

Abstract

Three clastic marly-shaly horizons occur within the Carnian carbonate rocks near Mežica and Črna na Koroškem, Slovenia. The marly-shaly beds directly overlie oolitic and oncoidal limestones. In the lowermost of these clastic horizons, several cephalophod species, including the most common Carnites floridus (Wulfen), were collected. In addition, bivalves, gastropods and sparse vertebrate remains are present. Within the second clastic horizon, there is a distinctive layer characterized by numerous specimens of the bivalve Hoernesia sturi (Wöhrmann), which was also found, though less commonly, in the lowermost clastic horizon. No fossil macrofauna was found in the third, uppermost clastic horizon. The oolitic and oncoidal layers at the base of all three clastic horizons also contain abundant echinoids and crinoids, as well as rare earliest thecideide brachiopods. The lithostratigraphic associations of the Carnian beds in the Mežica area express the same eustatically-driven cyclicity that is exhibited regionally in the “Raibl group” of the Eastern Alps.