First evidence of a large predatory plesiosaurian from the Lower Cretaceous non-marine Wealden facies' deposits of northwestern Germany

Sachs, S., Hornung, J.J., Lallensack, J.N. & Kear, B.P., November.2017. First evidence of a large predatory plesiosaurian from the Lower Cretaceous non-marine Wealden facies' deposits of northwestern Germany. Alcheringa 42, 501-508. ISSN 0311-5518.Here, we describe the incomplete mandible of a large-skulled pliosauromorph' plesiosaurian from the Lower Cretaceous (Berriasian) of northwestern Germany. The fossil derives from limnic-brackish Wealden facies' deposits of the Deister Formation (Buckeberg Group), and is preserved as a natural mould in fine-grained sandstone. Examination of the original remains, in conjunction with a three-dimensional photogrammetrically digitized cast', revealed a conspicuous rosette of symphyseal alveoli, which would otherwise typically characterize Early-Middle Jurassic macrophagous plesiosaurians including rhomaleosaurids and the pliosaurid Simolestes. The Deister Formation pliosauromorph' represents the first record of a large-bodied plesiosaurian macrocarnivore from the Wealden-facies' strata of Europe, and thus adds a previously unrecognized trophic level of aquatic apex predators to the Early Cretaceous non-marine ecosystems of Europe.