Children (23 direct children, 326 direct and indirect children):
Elasmosauridae
(tree size 80)
Polycotylidae
(tree size 27)
Rhomaleosauridae
(tree size 25)
Simolestes
(tree size 1)
Pliosauroidea
(tree size 6)
Plesiosauria
Pliosauridae
(tree size 59)
Plesiosauroidea
(tree size 68)
Cryptoclididae
(tree size 31)
Bathyspondylus
(tree size 1)
Aptychodon
Brimosaurus
Cymatosaurus
Discosaurus
Neoplesiosauria
Hexatarsostinus
Luetkesaurus
Stereosaurus
Raptocleidus
Xenopsaria
(tree size 4)
Apractocleidus
Cryptoclidoidea
Rhaeticosaurus
(tree size 1)
Plesiosauroidea