Wright J.K., Page K.N. (2006) The cardioceratid ammonite fauna of the Upware Limestone and Dimmock’s Cote Marl (Upper Jurassic) in Cambridgeshire, England // Proc. Yorkshire Geol. Soc. V.56. Pt.2. P.65-75.
The West Walton Formation (Dimmock's Cote Marl and Upware Limestone members) of Upware, Cambridgeshire, has yielded an abundant cardioceratid fauna. Three assemblages of Cardioceras, comprising eight nominal species, are described and figured. Faunas such as these from Maltonense-Tenuiserratum Subzone boundary beds are rare in the UK, and the Upware ammonites add significantly to our understanding of the manner in which Miticardioceras, a subgenus of Cardioceras important for correlation of Middle Oxfordian strata across northern Europe, appears in the UK. Ammonite assemblages from the Densiplicatum - Tenuiserratum transition reveal mixed nature, included index-species of both zones.