The table presented here sumarizes the several findings of orbitolinids in beds providing significant ammonites or immediately underneath ammonite-bearing strata, allowing a direct calibration of the assemblages on the standard ammonite zones. It is supplemented by information on orbitolinid occurrences in levels without ammonites but correlated on the regional sequence stratigraphic framework. The first category (directly dated by ammonites) is given a higher hierarchical weight than the second (indirectly dated from the sequence stratigraphic interpretation).