Well - we know of 3 sauropods which are certain - Apatosaurus, Brachiosaurus, and Camarasaurus. So that is a diplodocid. a Brachosaurid, and a Camarasaurid.
Mamenchisaurus is IMO very likely given it's Lost World history. I could also imagine at least 1 titanosaur being in the game. As for Diplodocus being in the game - it is certainly possible given the number of Morrison based dig sites in the game. But I could also imagine other diplodocoids as well - including Supersaurus, Dicraeosaurus (from the Tendaguru), or possible even Rebbachiosaurus or Nigersaurus from northern Africa.
Mamenchisaurus is IMO very likely given it's Lost World history. I could also imagine at least 1 titanosaur being in the game. As for Diplodocus being in the game - it is certainly possible given the number of Morrison based dig sites in the game. But I could also imagine other diplodocoids as well - including Supersaurus, Dicraeosaurus (from the Tendaguru), or possible even Rebbachiosaurus or Nigersaurus from northern Africa.