Difference between Plesiosaur, Polycotylid and Pliosaur vertebrae

[sander]

Dear members of the fossil forum.

Some time ago I bought several vertebrae from the Turonian layers of Goulmima, Morocco.

5 marine vertebrates have been found at that site until now.

These are Tethysaurus (mosasaur), Thililua (polycotylid), Manemergus (polycotylid), Libonectes (plesiosaur) and Brachauchenius (pliosaur).

I want to know if I have a fossil of each of these 4 groups from Goulmima.

Therefore I need to know how the vertebrae look of each group.

I know the difference between mosasaur vertebrae and the other 3 groups, but which differences exist between the other three?

Thanks in advance,

Sander