P_dolichodeirus_outgroupP_brachypterygiusP_guilelmiimperatorisTricleidusCryptoclidusOccitanosaurusMicrocleidusMuraenosaurusAlzadasaurusHydrotherosaurusThalassomedonOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Bardet_etal_1999a