I think the Rex statues "friend" might be a Parasaur. The only reason I say Parasaur is because I know Jen's love for Parasaurs. But it could be any dino really, i'm kinda hoping it's a little rideable Dodo myself lol.
Well i'm pretty sure it gonna be a desert biome where all the mysterious creatures will be, but yeah I think it will be another ARK.