Diversity and Ecology of a Middle Campanian (Late Cretaceous) Marine Reptile Assemblage from Skåne, Southern Sweden

Abstract: This study has looked at an assemblage of fossilised teeth from Mesozoic marine amniotes from the Kristianstad basin in southern Sweden in order to make an estimate of the ecomorph diversity within said assemblage through looking at the morphology of the teeth. This was done as a pilot study to see if further studies would be able to produce worthwhile results. The assemblage consists largely of isolated tooth crowns, mostly from small- to medium sized mosasaurs such as Clidastes and Eonatator, but also contains larger mosasaurs, as well as a couple of plesiosaurs and one species of a marine crocodile. The analysis was performed on images of teeth using software developed for use in morphometrics. The resulting graphs imply a division into three guilds; the first represented by the short and blunt teeth of the crocodilian, the second by the elongated teeth of the plesiosaurs, and the third by the knife-like teeth of the mosasaurs. Since the mosasaurs overlap to a high degree in tooth shape, but also show quite diversity in size, it is possible the main dividing factor would have been size rather than type of prey. Further studies would be able to get a more accurate image of the ecology of this fauna by increasing the number of specimen in the analysis as well as taking into consideration more factors from other studies of similar taxa, such as jaw sizes, bite marks and gut contents.