The lost snout of Richard Harlan’s specimen of Mosasaurus missouriensis has been rediscovered in the vertebrate palaeontology collections of the Muséum national d’Histoire Naturelle (MNHN) in Paris, France. The specimen (MNHN 9587) bears the handwritten description, ‘Amérique du Nord. Par M. Harlan.’, which translated reads, ‘North America. By/From Mr. Harlan’. Accession information indicates the specimen was a gift to the museum prior to 1860 and was likely gifted from Harlan’s estate after his death. We examine the available history of the collection of the specimen present a description of the rediscovered snout, and demonstrate conclusively the conspecificity of M. maximiliani Goldfuss, 1845 and M. missouriensis (Harlan, 1834a) by providing a revised diagnosis of the taxon.

In their comment, Wesselingh et al. say that pronounced glacioeustacy renders the detailed discussions about age intervals obsolete and that they fail to see the application of the Haq curves for age estimates in the Maassluis Formation can make much sense. We would argue the following:

Geological structures and Late Quaternary stratigraphy of the shallow subsurface along the southernmost Danish North Sea coast have been investigated using seismic data and shallow boreholes. A large-scale glaciotectonic thrust complex has been mapped in an area of 15 km by 40 km in the Fanø Bugt area. The affected succession consists of Neogene and Quaternary sediments deformed down to a depth of 200 – 360 m. A kineto-stratigraphic correlation to onshore glaciotectonic deformation suggests that the deformation took place during a westward advance stage of the Late Saalian (Warthe) glaciation. The western limit of the glaciotectonic structures constitutes an N-S striking deformation front situated 35 km off the west coast. Based on the glacial stratigraphy outside the deformation front, it is suggested that the same ice advance that caused the glaciotectonic deformation, eroded the top of the thrust sheets, and subsequently deposited a lower unit of meltwater sediments and an upper heterogenous glacigenic unit. The upper glacigenic unit forms a bank about 30 km offshore. Between the bank and the shore, the surface of the Saalian glacial landscape forms a wide depression ca. 50 m below sea level. This basin has controlled deposition in the area since the late Saalian and is filled with sediments of late Saalian, Eemian, Weichselian and Holocene age. The base of the Holocene marine deposits is thus a flat erosional surface extending eastward several kilometres below the onshore coastal areas and the northern Wadden Sea. This surface was transgressed 8800 years ago. An inverted, in plan view T-shaped, Holocene sand accumulation approximately 25 km long, 30 km wide and 15 – 25 m thick is situated on top of this surface at Blåvands Huk. According to recent estimates by the Danish Coastal Protection Board some 2.5 million m3 sediments are supplied annually to the system from the north. In the last 3000 years, 25 km of the west coast and the associated shoreface slope have prograded ca. 3 km towards the west forming a barrier spit complex. Large aeolian dunes and cover sands now conceal the spit complex. Extending twenty km west of Blåvands Huk is a highly dynamic bank, the Inner Horns Rev, with active sand-accumulation on the slopes. The Inner Horns Rev bank has grown ca. 3.5 km westward during the last 800 years. The deposits seem to be sourced by the coastal longshore sand transport from the north. The Outer Horns Rev was previously assumed to be a Saalian terminal moraine. However, this investigation reveals that it is also mainly a Holocene marine accumulation landform, but sourced from the west. Other sand accumulations, which are situated 20 – 30 km west of the coast, are probably sourced from both the south and the west.

The mosasaurine Clidastes sp. is recognised from cranial and post-cranial remains collected at four localities in NW Germany. Cranial material was found in pelagic turbiditic marls which crop out near the village of Beckum, while post-cranial skeletal elements were collected from sandy limestones exposed near the villages of Schöppingen, Coesfeld and Billerbeck. In stratigraphic order, the units producing these specimens of Clidastes are the Coesfeld, Baumberge and Beckum formations of late Campanian (Late Cretaceous) age. The cranial material comprises the anterior part of a skull and a single isolated tooth, while post-cranial bones comprise a few isolated vertebrae and a partial skeleton including forelimb bones and an articulated vertebral column. Clidastes is known to date from the western North Sea Basin (England), southern Sweden, as well as from North America (Western Interior Seaway and Gulf Coast).

A revised Upper Cenozoic stratigraphic framework of the Dutch sector of the North Sea Basin is presented whereby offshore stratigraphic units are integrated or correlated with onshore units. The framework is based on an integrated stratigraphic approach that combines elements of lithostratigraphy, seismostratigraphy and allostratigraphy. Offshore formations are redefined in terms of seismofacies and lithofacies associations, and are differentiated on the basis of common genesis and stratigraphic position. These facies associations represent five major depositional environments, which occur in repetitive successions in the subsurface of the Netherlands: Marine, Coastal, Glacial, Fluvial, and Local Terrestrial. Five conceptual basin-wide bounding discontinuities are identified in the North Sea-Basin that span land and sea. They are represented by both seismostratigraphic and lithostratigraphic unconformities and interpreted as surfaces that formed as a result of North Sea Basin-wide changes in depositional systems. Their formation relates to sea level rise, continental-scale glaciations, and tectonic processes. The bounding discontinuities separate informal allostratigraphic groups of formations that have a grossly uniform geologic setting in common. While the allostratigraphic principles provide a view on the stratigraphy on the largest spatial and temporal scale, the genetic concept facilitates mapping on a local scale.

The present study consists of a synthesis of the lithostratigraphy, geotechnical properties, geometry and distribution of Eocene and Quaternary deposits of the Belgian continental shelf. It is based on available large datasets (seismics, cores, cone penetration tests) and their interpretations synthesised from numerous studies from the last 20 years. A significant effort has been focused on data digitisation and integration into appropriate GIS software packages in order to compare the data in a much more dynamic and flexible way. New insights have been proposed on the lithostratigraphy and geotechnical properties of offshore and onland deposits.

An application is presented for the selection of wind farm implantation sites. Geological and geotechnical aspects of direct interest for wind farm implantation site selection have been focused on, such as the stability of the offshore wind turbine structures and the minimization of environmental impacts on the seabed. Sites suitable for wind turbines using monopile structures on the Belgian continental shelf are proposed.

Aigialosaurs have been recognised as a group of semi-aquatic marine reptiles for over one hundred years. While the taxonomic status of aigialosaurs has changed little in the past century, the interfamilial relationships have been modified considerably making the phylogenetic relationships between aigialosaurs, mosasaurs, dolichosaurs, coniasaurs, varanids and other squamates a topic of much debate. The monophyly of the family Aigialosauridae has been contested by recent studies and remains highly questionable. The higher-level relationships of mosasauroids within Squamata remain problematic with studies placing mosasauroids outside of Varanidae, Varanoidea and even Anguimorpha. These findings conflict with earlier views that aigialosaurs (and by association mosasaurs) were closely related to Varanus. This study concludes that further descriptions of aigialosaur taxa are needed, and several key flaws need to be addressed in the data matrices that have been used in previous studies. This should facilitate the clarification of aigialosaur systematic relationships both within Mosasauroidea and Squamata.

Tylosaurus kansasensis sp. nov. is described herein on the basis of thirteen specimens collected from the Smoky Hill Chalk (upper Coniacian) of western Kansas, USA. The new species, originally designated Tylosaurus n. sp., co-occurred with T. nepaeolicus and exhibits a number of primitive characters that place it in a basal position in the mosasaur phylogeny. Among the key differences separating this species from other tylosaurines are a shortened, more rounded pre-dental process of the premaxilla, a distinctive quadrate lacking an infrastapedial process, and a parietal foramen located adjacent to the frontal-parietal suture.

The Upper Cretaceous deposits of New Jersey and Delaware produced the first mosasaur specimens collected in North America. Recent recovery of mosasaur specimens from streambank exposures and new excavation sites has increased our knowledge of the stratigraphic distribution of these animals in the northern Atlantic coastal plain. Reassessment of the source and age of mosasaur specimens from the Big Brook site and other localities in Monmouth County (NJ) has greatly increased the number of known Campanian mosasaur specimens from this region. Two main taphonomic occurrence modes are noted: 1 - single, worn and broken bones and isolated teeth in mixed faunal deposits probably accumulated due to current action in nearshore environments; 2 - partial skeletons, skulls and single bones in deeper-water settings were the aftermath of biological modification of carcasses and deadfalls. The mosasaurs of the New Egypt Formation represent some of the last (i.e., stratigraphically highest) mosasaur fossils in North America. Mosasaur extinction was due to the collapse of the rich Late Cretaceous marine food web at the K/T boundary. Subsequently in the early Paleocene, with the disappearance of the mosasaurs, crocodilians became the apical predators of the marine environment in this area.

We describe a new marine varanoid, Judeasaurus tchernovi gen. et sp. nov., on the basis of a partial skull recovered from the Middle Cenomanian of the Judean Hills. The new taxon possesses a unique suite of characters exhibited in terrestrial varanoid lizards on the one hand and derived mosasauroids on the other. The characters that relate it to terrestrial varanoid lizards include broad premaxilla, anteriorly depressed maxillae underlying the nasal capsule, extensive postorbitofrontal-parietal contact and vertically oriented parietal rami. Derived mosasauroid characters include a question-mark shaped quadrate, fused frontals, intricate fronto-parietal suture and moderately retracted nares. The shape of the supratemporal and its syndesmotic articulation with the parietal distinguishes the new taxon from any other known specimen. The dentition exhibits elongate and narrow cylindrical roots lacking resorption pits, a condition reminiscent of Coniasaurus, but crowns are small, slightly recurved and conical. Taken together, the new taxon possesses a suite of characters suggesting dolichosaurid affinities.

Sediments in north-central Texas, ranging in age from >117 to 85 Ma, represent a variety of terrestrial and marine depositional settings. Isotopic analyses of wood fragments found throughout the section allow correlation to the standard secular marine δ13C curve because of characteristic peaks at the Aptian-Albian and Cenomanian-Turonian boundaries. Consistency of the north-central Texas δ13C curve with the marine standard facilitates correlation among non-marine and marine environments on a global scale. Radiometrically dated ammonite zones recognised in Texas provide calibration for the Cenomanian and Turonian portions of the section. Cenomanian and Turonian sediments in north-central Texas preserve the oldest (96 Ma) and the youngest (<85 Ma) well-documented Coniasaurus, a dolichosaur also known from the southern North Sea Basin during that interval. Haasiasaurus, the oldest known well-documented early mosasaur, is found at ‘Ein Yabrud, Israel (98 Ma), followed by other poorly dated Cenomanian taxa from the eastern Mediterranean region, and then by Dallasaurus turneri and Russellosaurus coheni in Texas (92 Ma) and Tethysaurus (90.5 Ma) in Morocco. Neither shifts in δ13C nor large-scale sea level change seem to have influenced dolichosaur or mosasaur evolution in substantial ways during the Cenomanian and Turonian stages.