HORNUNG, T. (2004)

Die Gattung Cymaceras QUENSTEDT 1887 aus dem Kimmerdige 2 der Nördlichen Frankenalb
(Alter Stbr. Ludwag / Ofr.)

The genus Cymaceras Quenstedt 1887 from Kimmeridgian 2
(Ludwag quarry; Northern Franconian Switzerland, Upper Franconia)

Abstract

Cymaceras Quenstedt 1887/88 is one of the rarest ammonite genera occuring in the Late Jurassic of Upper Franconia (Northern Bavaria, Germany). By comparison to the broad spectrum of ammonite monographers, only few authors were engaged with descriptive and interpretative studies about the at least two subgenera and four subordinated species integrated to Cymaceras. Present studies awardes Cymaceras the status of a substage index-fossil representative for the Kimmeridgian 1b in Southern Germany.
The two quarries near Ludwag (Bamberg district) are famous for both narrow-spaced facies-distribuation and excellent preserved ammonite faunule within bedded limestones (shallow basinal facies) as well as biostromal facies (reef detritus facies). Only one location within the lower quarry outcropping the guilherandse ammonite subzone representativ for Kimmeridgian 1b: 21 classifiable specimen of the macroconch genus Cymaceras (subgenus Cymaceras) and two specimen of the microconch genus Cymaceras (subgenus Trochiskioceras) were found in reef-related biostromal facies. This study includes 11 bodily preserved, complete specimens, collected in the years 1992 to 1994.