Occurrences of the ammonite genus Clydoniceras Blake, 1905 in the Middle Jurassic (Upper Bathonian, Discus Zone) of NW Switzerland

Two ammonites of the genus Clydoniceras Blake, 1905, are described and figured for the first time from the Upper Bathonian of NW Switzerland. One specimen is from the Ächtelmatt site near Anwil (Canton Basellandschaft). The complex depositional conditions, especially those during the Late Bathonian, of this famous section are discussed. The second specimen comes from a road cut at La Gainaiche, north St-Brais (Canton Jura). The St-Brais Member (formerly Calcaire roux sableux) within the Ifenthal Formation is introduced.