There will be a

Previous 50 - viewing x out of y - Next 50

On all the other topic pages (the one displaying the latest messages won't have the "previous" link as there are no newer messages of course).

What is somewhat... illogical about this is that "Previous" links to newer message, "Next" links to older posts.

Which is not a big problem, but can be confusing for 23-34 seconds.