Morphological variability patterns in the Balearites-Pseudothurmannia genera boundary (Ammonoidea, late Hauterivian): taxonomic and biostratigraphic implications

As for many other ammonoid groups, the Hauterivian family Crioceratitidae has been traditionally approached from a strictly typological viewpoint, leading to considerable taxonomic oversplitting. Balearites angulicostatus (d’Orbigny, 1841 d’Orbigny, A. 1840–1842. Paléontologie française. Description zoologique et géologique de tous les animaux mollusques et rayonnés fossiles de France. Terrains Crétacés, Tome 1er, Céphalopodes. Paris, 662 pp....