Abstract
Abstract
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.
Publisher
Cambridge University Press (CUP)
Reference84 articles.
1. Oceans of Kansas, Second Edition
2. How Plesiosaurs Swam: New Insights into Their Underwater Flight Using “Ava”, a Virtual Pliosaur
3. Vandellius, D. ,1761. Epistola de Holothurio, et Testudine coriacea ad Celeberrimum Carolum Linnaeum Equitem Naturae Curiosorum Dioscoridem II, Volume 12. Conzetti, Padova.
4. A new specimen of the elasmosaurid plesiosaur Zarafasaura oceanis from the Upper Cretaceous (Maastrichtian) of Morocco;Lomax;Paludicola,2013
5. A juvenile Tuarangisaurus keyesi Wiffen and Moisley 1986 (Plesiosauria, Elasmosauridae) from the Upper Cretaceous of New Zealand, with remarks on its skull ontogeny