Pdf: http://www.palaeodiversity.org/pdf/Palaeodiversity_1_10_141-166.pdf

The authors describe a fossiliferous section around the Sauzei/Humphriesianum zonal boundary (Lower Bajocian, Middle Jurassic) near Balingen-Streichen (near the Hohenzollern Castle, Swabian Alb, SW Germany). Two new ammonite faunal horizons are introduced, the horizon of Otoites dilatus of the Sauzei Zone and the horizon of Sonninia ohmerti of the Humphriesianum Zone, Pinguis Subzone. The latter is of special interest because it comes from a coralliferous bed (“Korallenschicht”) which originally Oppel (1856) took as the boundary between his zones of Ammonites Sauzei and Ammonites Humphriesianum. A further faunal horizon of the Sauzei Zone – that of Stephanoceras macrum – is described from Gosheim (Swabian Alb, SW Germany). The previously published data around the Sauzei/Humphriesianum zonal boundary are critically reviewed, and we propose a preliminary correlation of several sections around the Sauzei/Humphriesianum zonal boundary in the area from the Middle Swabian Alb to the Upper Rhine near Lorrach. A new ammonite species, Sonninia ohmerti n. sp., index of the ohmerti horizon, is described.