[quote=@Raindeer]
I came to think, now that megafauna has been brought up.

What are the parameters of the fauna in the ocean/seas/rivers? What would be considered megafauna in those areas?

Would a serpent that spends it's youth in the rivers of the jungles and as it grows older and bigger it travels downstream into the sea be a plausible creature to have exist?
[/quote]

Would it live in the lake as well? I think it would be an interesting idea to incorporate into the disappearing fish dilemma with the saurians.