The first isolated and well-preserved phalanx (autopodial element) of a generically and specifically indeterminate (probably xenopsarian) plesiosaur from the Maastrichtian type area (south-east Netherlands) is described and illustrated. Morphological features of this bone, such as the articular subchondral surfaces, allow it to be distinguished from phalanges of co-occurring mosasaurs (Mosasauridae, Squamata) and could imply rapid growth in plesiosaurs, similar to that observed in extant leatherback turtles. The large size of the phalanx indicates that it originates either from a large juvenile or from a paedomorphic individual. The paucity of plesiosaur remains in biocalcarenites of late Maastrichtian age in the Maastrichtian type area could be explained by the shallow settings, in which these strata were deposited, which may not have offered suitable ecological resources conducive to abundant plesiosaur inhabitation. Presumably, the lack of steep continental slopes in the type Maastrichtian, at which oceanic upwelling of cold, nutrient-rich water supported a higher prey density for pelagic predators such as plesiosaurs, may have inhibited plesiosaur occupation. Rather, decomposing floating carcasses may have been the source of dissociated elements of plesiosaurs in this area, such as isolated teeth, vertebrae and the autopodial element described here.

Knowledge about marine reptile diversity and disparity during the Late Jurassic is increasing. This contribution describes marine reptile skeletal elements (ichthyosaur and plesiosaur) from Kingofjeld mountain in NE Greenland. The assemblage is early Late Oxfordian (Late Jurassic) in age, and consists of c. 100 disarticulated skeletal elements. The location is of biogeographic importance as it was at the time situated between the Boreal realm and the Tethys Sea and is promising in terms of future prospecting.

Remains of elasmosaurid plesiosaurs are exceedingly rare in the type-Maastrichtian strata (Late Cretaceous, southeast Netherlands and northeast Belgium), in stark contrast to relatively common skeletal remains of mosasaurs. Here, we present an analysis of δ13C stable isotope values for tooth enamel of two elasmosaur teeth from the type Maastrichtian. The δ13C signal is a proxy for foraging area, trophic level and diving behaviour, the net value of which in these rare elasmosaurs turns out to be not noticeably different from that for the much commoner mosasaurs in the type Maastrichtian. Therefore, the rarity of elasmosaurs in the area probably reflects a primary near-absence of such reptiles during the latest Cretaceous, rather than a taphonomic artefact.

New elasmosaurid plesiosaur specimens are described from the Early Maastrichtian of Angola. Phylogenetic analyses reconstruct the Angolan taxon as an aristonectine elasmosaurid and the sister taxon of an unnamed form of similar age from New Zealand. Comparisons also indicate a close relationship with an unnamed form previously described from Patagonia. All of these specimens exhibit an ostensibly osteologically immature external morphology, but histological analysis of the Angolan material suggests an adult with paedomorphic traits. By extension, the similarity of the Angolan, New Zealand and Patagonian material indicates that these specimens represent a widespread paedomorphic yet unnamed taxon.