Franconiasaurus brevispinus is a new early plesiosaur established based on two three-dimensionally preserved skeletons from the Lower Jurassic of Germany. It lived during the late Toarcian (∼175 Mya), near the onset of an Early–Middle Jurassic turnover of marine reptiles. Franconiasaurus displays an intriguing combination of characters of early and later-diverging plesiosaurs. Phylogenetic analyses place it as the sister taxon to Cryptoclidia, bridging an evolutionary gap between Plesiosaurus-like forms and microcleidids on the one hand, and cryptoclidids, leptocleidians, and elasmosaurids on the other hand.
Reconstruction: Joschua Knüppe
PUBLICATION: Sachs, S., Eggmaier, S., Madzia, D. 2024. Exquisite skeletons of a new transitional plesiosaur fill gap in the evolutionary history of plesiosauroids. Frontiers in Earth Science 12: 1341470, https://doi.org/10.3389/feart.2024.1341470.