Report on the 3rd International Meeting of the IUGS Lower Cretaceous Ammonite Working Group, the “Kilian Group” (Vienna, Austria, 15th April 2008)

The discussion is mainly focused on the Hauterivian and Barremian zonal schemes. For the Hauterivian Stage, the main changes concern the Subsaynella sayni and Balearites balearis Zones with the introduction of one horizon (Subsaynella begudensis Horizon) and four subzones (B. balearis, Binelliceras binelli, Crioceratites krenkeli, Spathicrioceras seitzi subzones), respectively. For the Lower Barremian, the main amendments concern the introduction of two subzones in the Taveraidiscus hugii auctorum Zone (T. hugii auctorum and Psilotissotia colombiana subzones) and of four horizons in the Kotetishvilia compressissima Zone (Holcodiscus fallax, Nicklesia didayana, Heinzia communis and Subtorcapella defayae Horizons). The Coronites darsi Zone is replaced by the Moutoniceras moutonianum Zone in which two horizons occur (C. darsi and Heinzia caicedi Horizons). The base of the Upper Barremian is defined by the base of the Toxancyloceras vandenheckii Zone and Subzone. The former Hemihoplites feraudianus and Martelites sarasini Zones are lowered in rank to subzones of the Gerhardtia sartousiana and Imerites giraudi Zones, respectively.