Co-occurrence of Neusticosaurus edwardsii and N. peyeri (Reptilia) in the Lower Meride Limestone (Middle Triassic, Monte San Giorgio)

A groundbreaking discovery at the UNESCO World Heritage Site of Monte San Giorgio, Switzerland, has revealed the co-occurrence of two pachypleurosaurid species, Neusticosaurus edwardsii and N. peyeri, in the Lower Meride Limestone (Middle Triassic). This challenges the long-held hypothesis that only one anagenetic lineage existed for Neusticosaurus species in this region, prompting a reevaluation of their evolutionary history. The study, based on recent excavations in the Cassina beds, updates the stratigraphic distribution of these reptiles and provides new insights into their phylogenetic relationships.

Stockar, R., & Renesto, S. (2011). Co-occurrence of Neusticosaurus edwardsii and N. peyeri (Reptilia) in the Lower Meride Limestone (Middle Triassic, Monte San Giorgio). Swiss Journal of Geosciences, 104(S1), 167–178. https://doi.org/10.1007/s00015-011-0077-x