An 8.5 m long ammonite drag mark from the Upper Jurassic Solnhofen Lithographic Limestones, Germany

Trackways and tracemakers preserved together in the fossil record are rare. However, the co-occurrence of a drag mark, together with the dead animal that produced it, is exceptional. Here, we describe an 8.5 m long ammonite drag mark complete with the preserved ammonite shell (Subplanites rueppellianus) at its end. Previously recorded examples preserve ammonites with drag marks of < 1 m. The specimen was recovered from a quarry near Solnhofen, southern Germany. The drag mark consists of continuous parallel ridges and furrows produced by the ribs of the ammonite shell as it drifted just above the sediment surface, and does not reflect behaviour of the living animal

The Santonian stage and substages

The recognition of the Coniacian-Santonian boundary is easy with good correlation of macro- and microfossil evidence. The Santonian Working Group (SWG) recommends the lowest occurrence of Cladoceramus undulatoplicatus (Roemer) as the marker for the Coniacian-Santonian boundary. As yet, the SWG cannot make a formal proposal for a Boundary Stratotype Section, because the biostratigraphy must be better known and integrated first. Three candidates for Boundary Stratotype Section, Olazagutia Quarry (Navarra, Spain), Seaford Head (Sussex, England) and Ten Mile Creek (Dallas, Texas, USA) were selected for further decision. To achieve a useful subdivision of the Santonian into substages a better understanding of taxa ranges and correlation through different biogeographic realms is needed. Formal proposals for subdivision would be premature at present, but a three-fold division is favoured

Definition and global correlation of the Santonian-Campanian boundary

Review of biostratigraphical evidence from different regions shows that criteria used by workers on various marine fossil groups to define the Santonian-Campanian boundary differ considerably in relative age and position. Probably the most widely recognizable of these criteria is the extinction of the distinctive crinoid Marsupites testudinarius (North America, Europe, Asia, North Africa, Australia), which, coincides exactly with two separate definitions of the boundary. A comparison of evidence from upper Santonian and lower Campanian successions in widely separated regions allows a series of important biostratigraphical markers to be placed in correct order. -from Author