Marine vertebrates from the Santonian coastal carbonates ofnorthwestern Germany – a tool for the reconstruction of a Proto-North Sea Basin intertidal dinosaur-exchange bridge

Abstract

Abstract A diverse vertebrate fauna, dominated by sharkteeth, is recorded from conglomerates within the limestonesof the Upper Cretaceous (Santonian) BurgsteinfurtFormation of northwestern Germany. The conglomeratebeds comprise carbonatic, glauconitic and phosphatenodules, as well as Triassic, Jurassic and Cretaceous extraclasts.The Burgsteinfurt Formation conglomerates containfining-upwards parasequences 2–20 cm in thickness,interpreted as tempestite layers within a unit formed bylarger-scale Milankovitch Cycles. The presence of the inoceramidSphenoceramus patootensis and belemnite Gonioteuthisgranulata indicate a late Santonian age for theunit. The studied vertebrate fauna from the Weiner Eschlocality consists of 20 selachian species (14 macroselachiansand 6 microselachians), a few teleosts, rare marinemosasaur remains, and one tooth from a theropod dinosaur.95% of the vertebrates in the assemblage are depositionallyautochthonous, with the remaining materialreworked from older underlying Cenomanian–Coniacian(lower Upper Cretaceous) limestones. On the basis of observedsedimentary structures, the scarcity of deep-seaselachians, and the dominance of the Mitsukurinidae(59% of the preserved shark fauna) in the fossil assemblage,the unit is interpreted as a shallow (0–3 metresdeep), subtidal, nearshore environment, or even subaerialcarbonate-sand islands, located on the southern marginof a submarine swell. The presence of a Santonian theropodin this deposit, and other dinosaur records in northernGermany, together support the interpretation of ashort-lived uplift event with strong upwelling influence forthe Northwestphalian-Lippe submarine swell north of theRhenish Massif in the southern Proto- North Sea Basin. Anew migration model for dinosaurs moving along carbonatecoasts or intertidal zones of shallow carbonate-sand islandsin Central Europe is presented, which may explainthe scattered distribution of dinosaur remains across Europein the Upper Cretaceous.