Notes on the systematics, morphology and biostratigraphy of fossil holoplanktonic Mollusca, 19. Pteropods (Gastropoda, Euthecosomata) from the Eocene Lillebaelt Clay Formation (Denmark, Jylland)

Sideritic fossiliferous concretions from the Eocene Lillebaelt Clay Formation, collected ex situ on the beach at Trelde Næs (Jutland, Denmark) were found to yield two common pteropod species: Heliconoides lillebaeltensis spec. nov. and H. mercinensis (Watelet & Lefèvre, 1885), the latter known to date from a Late Palaeocene-Ypresian interval. A single further specimen might represent the species Limacina pygmaea (Lamarck, 1805), known only from the Lutetian. A study of the dinoflagellate assemblages in six of the concretions allowed an age assignment of Early Lutetian.