Barremian rhyncholites (Lower Cretaceous Ammonoidea: calcified upper jaws) from the Serre de Bleyton (Département Drôme, SE France)

Abstract

Seven calcified upper jaw tips of Rhynchoteuthis astieriana d’oRbigny and Palaeoteuthis infira (shiMansky) from the Serre de Bleyton section (Dept. Drome, SE France) were redeposited from an outer shelf into an upper slope (upper bathyal) environment embedded in a highly fossiliferous Barremian bioclastic limestone. They represent a low diverse and poor preserved small Barremian pelagic rhyncholite fauna, also described from a few Tethyan and Alpine localities between Cuba, the Crimea, and the Caucasus. Rhynchoteuthis and Palaeoteuthis may most probably represent calcified tips of upper jaws of various taxa of Tethyan ammonites, e.g. of the Phylloceratina (Phyl loceras, Sowerbyceras), Lytoceratina (Tetragonitidae), and/or some Ammonitina (Arnioceras, Eleganticeras, Hildoceras, Aconeceras). But due to their scarcity, poor preservation, and the allochthonous occurrence, the Serre de Bleyton rhynchoteuthids do not contribute further new knowledge to taxonomy, palaeoecology, stratigraphy or basinal history.