Original paper

Psiloceratid ammonites from the Lower Hettangian of the Karwendel Mountains (Northern Calcareous Alps, Austria) and their biostratigraphic significance

von Hillebrandt, Axel; Kment, Kurt


Three Lower Hettangian sections in Austria that include the famous Callipyllum Bed are described. Below the Calliphyllum Bed in the Rissbach section, a limestone bed yielded Psiloceras angulocostatum n. sp. and Psiloceras cf. planorbis. In the Fonsjoch and Baumgartenbach sections, the Calliphyllum Bed is marked by a diverse and well-preserved ammonite fauna belonging to different ammonite horizons. The genus Neophyllites is represented by two species which are important for biostratigraphic correlation with NW Europe. Rare phragmocones of relatively large representatives of the Psiloceras tilmanni group are found in the Calliphyllum Bed and are probably reworked from older ammonite beds. Psiloceras calliphyllum, the most common ammonite in this bed, is most similar to P. erugatum, the oldest Psiloceras in Great Britain. Psiloceras strongolum is found below P. calliphyllum and micro- and macroconchs of both species are present. The microconchs of both species show a more complicated suture line than similar NW European species. The alpine Psiloceras cf. planorbis which has no nodes and a denticulated suture line, could be the forerunner of the NW European Psiloceras planorbis. Some of the Austrian species are related to South and North American forms.


jurassicnorthern calcareous alpsammoniteshettangianstratigraphy