A Late Valanginian Mediterranean ammonoid fauna from the Lunz Nappe (Northern Calcareous Alps; Lower Austria)

Early Cretaceous ammonoids were collected from the Northern Calcareous Alps in the southeasternmost part of the Lunz-Nappe (Perchtoldsdorf Syncline) near Vienna. The cephalopod assemblage, the easternmost Early Cretaceous assemblage from the Northern Calcareous Alps, derives from the Rossfeld Formation, indicating a mid Late Valanginian age (Neocomites peregrinus Zone). The deposition of the sandy limestones and marly limestones in this interval occurred during unstable environmental conditions which led to a preserved autochthonous fauna comprising additional transported allochthonous ammonoid specimens. The-ammonoid fauna yields 6 different genera, each apparently represented by 1-2 species. Ammonitina are the most frequent -components (Haploceras, Neocomites, Jeanthieuloyites), followed by the lytoceratids (Lytoceras), the phylloceratids (Phylloceras), and ancyloceratids (Himantoceras). The cephalopod fauna consists of Mediterranean elements dominated by neocomitids.