Palaeoclimate perturbations before the Sheinwoodian glaciation: A trigger for extinctiond during the 'Ireviken Event'
Telychian to Sheinwoodian conodonts (Pterospathodus eopennatus ssp. n. 1 Zone through the Ozarkodina sagitta rhenana Superzone) were studied in detail for their oxygen isotope composition. The Upper Kockelella ranuliformis and Ozarkodina sagitta rhenana Zones represent the peak interval of the Sheinwoodian positive δ18Oapatite excursion reflecting the coolest conditions with marine sea–water tempe