Bardet, N. Godefroit, P. Sciau, J. 1999 A new elasmosaurid plesiosaur from the Lower Jurassic of southern France Palaeontology 42 927-952 P_dolichodeirus_outgroup P_brachypterygius P_guilelmiimperatoris Tricleidus Cryptoclidus Occitanosaurus Microcleidus Muraenosaurus Alzadasaurus Hydrotherosaurus Thalassomedon Osteology Maximum Parsimony Based on reanalysis of the original matrix. Bardet_etal_1999a