Go to first unread post

Where has this feature gone? Used to be that this button was at the top of the page once you were inside a thread. That way if you found yourself (for example) at the first post in a long thread which you had already visited it would take you to content that was new since your last visit. Now you have to scroll through to find where you left off.

I know you can get to the first unread post from outside the thread by clicking on a star icon by the title. But no way to do it once you are inside the thread anymore.

I would love to see it return.