The only way water/land creatures survive that fall is if the water's impact zone has created a fairly deep lake (actually -really- deep, compared to the shallowish water of the rest). Most of the concept art actually shows all the "swamp" as very deep, in fact, so maybe that is actually canon at that point, but it's canon that elsewhere it's shallow, so it's unlikely.
However, such creatures might have been brought into there by other means; unsure.
Basically, we don't know if there could be others besides those mentioned canonically and used for that S&T contest entry.