We report the discovery of a new species of marine reptile, a mosasaur, from the Upper Cretaceous (Maastrichtian) of The Netherlands. Prognathodon saturator sp. nov. is represented by an almost complete skull and much of the postcranial skeleton, and is one of the largest mosasaurs discovered to date. The stout skull and extremely massive jaws are more powerfully built than in any other known mosasaur. Bite marks, the partial disarticulation and scattering of the skeleton, and the presence of associated teeth of Squalicorax and Plicatoscyllium suggest extensive scavenging by sharks.

This is the final volume of the SPLASHCOS research network and marks the completion of an international and collaborative survey to compile and evaluate the known records of underwater material around Europe's coastlines, deposited during periods of low sea level and subsequently drowned by sea-level rise at the end of the Last Glacial Period. Some of these underwater finds, especially those exposed in the intertidal zone, have been known about since the last century but have languished in obscure publications, museum archives, or national sites and monument records. Systematic underwater investigation

This paper discusses the significance of the southern North Sea for research on the human occupation of northwest Europe after the Last Glacial Maximum (LGM). Recent insight into the survival of post-LGM land surfaces and palaeolandscape structures points to the potential preservation of Late Palaeolithic and Mesolithic sites in this area. Finds of well-preserved materials (including artefacts of bone, antler and wood, as well as human remains) from various zones along the Dutch and British coasts corroborate this idea, whilst underwater excavations of eroding sites at Bouldnor Cliff (UK) and Maasvlakte-Rotterdam (NL) underpin the possibilities of gaining further insight into human behaviour in the context of submerging landscapes. Although the significance of the southern North Sea with regard to the Mesolithic is gradually exposed, there is still a lot to learn. The terrestrial archaeological records from both sides of the present-day North Sea yield indisputable evidence for hunter-gatherer presence from at least 13,000 BP. Successions of Magdalenian/Creswellian/ Hamburgian, Federmesser Gruppen and Ahrensburgian people (re)colonised the northwest European plain, interrupted by short-lived cold spells. Although it is expected that the southern North Sea must have been inhabited, and maybe even more intensively than the present-day dry land, archaeological evidence is still missing. Despite the presence of vast amounts of mammalian remains and the availability of many radiocarbon-dated bones, there is a striking lack of material post-dating the LGM and pre-dating the Holocene, whilst remains dated to the early Upper Palaeolithic show no evidence of human interference. At this stage, it is probable that taphonomic factors and research biases are responsible for this picture. This marks a sharp contrast with the early Holocene record, where numerous Mesolithic artefacts, as well as human remains, provide evidence for human occupation of the area. Materials are exposed on the sea floor, evidencing gradual erosion of early Holocene land surfaces. Although the number of sites is increasing, little is known yet about how the submerged record can be connected to the terrestrial record. Indeed, the central question here is how the submerged Mesolithic record compares to, or differs from, the terrestrial record. In order to answer this question, targeted archaeological research is needed, along with an understanding of taphonomic processes and increased insight into landscape dynamics. From a northwest European perspective, the present state of knowledge about the submerged post-LGM prehistoric archaeology of the southern North Sea demonstrates its huge research potential.

The North Sea bed host remains of Pleistocene and Early Holocene landscapes that were, mostly gradually, inundated following the last deglaciation. Archaeological remains from the seabed obtained by fishing, dredging, and sand suppletion include human skeletal remains. Radiocarbon dating reveals that most of these are Mesolithic although a few Late Palaeolithic and historic remains are represented. Samples with known stable isotope ratios δ 13 C and δ 15 N show that Mesolithic inhabitants of 'Doggerland' had a significant component of freshwater fish in their diet. This means the 14 C dates are subject to a reservoir effect mainly determined by the freshwater bodies at the time. Because of the lack of context, the magnitude of the reservoir effect cannot be derived, so that the 14 C dates cannot be precisely calibrated to absolute ages. However, a distinct correlation is observed between the δ 15 N values and the (uncalibrated) 14 C dates, suggesting a chronological development.

The rise of Holocene (ground)water level as a function of relative sea-level rise has been extensively investigated in the western Netherlands, whereas few studies focused on the Flevo lagoon in the central Netherlands. In this study, all available ,4 C dates from the base of basal peat overlying the top of compaction-free Pleistocene sand in the former Flevo lagoon were evaluated in order to reconstruct water-level rise for the period 5300-2000 cal. yr BC. The present basal peat 14 C data set from Flevoland consists of two subsets: (1) the largely new Almere data (41 dates) representing the southern part of the former Flevo lagoon, with 26 dates especially carried out for this study, and (2) the existing Schokland data (21 dates) representing the eastern part of the lagoon. The Schokland area is located about 50 km from the Almere area. The quality of all basal peat time-depth data was palaeo-ecologically and geologically evaluated, all 14 C dates were calibrated to the same standards, and error margins of age and altitude determination were estimated. After plotting the data as error boxes in time-depth graphs, lower limit curves for water-level rise were constructed for both data sets. Comparison with the mean sea-level curve for The Netherlands ( Van de Plassche, 1982) suggests that water-level rise in the Almere area between 5300 and 2000 cal. yr BC corresponded closely to the rise in mean sea level. The same holds for the Schokland area for the period 5000-4200 cal. yr BC. For the period 4200-2000 cal. yr BC, however, the Schokland data suggest water-level rise to have been slower than mean sea-level rise, leading to local water levels apparently below mean sea level, which is virtually impossible. Hypothetical explanations for this discrepancy include: errors and uncertainties in mean sea-level and local water-level reconstruction, basin subsidence and temporal differences in intra-coastal tidal damping. The presently available data are inconclusive at this point and Holocene water-level rise in the Flevo lagoon awaits further investigations.