I could have sworn that clicking on the bold took me to the first page of threadAssuming you are logged in, the thread title in the main list is emboldened if there is unread content. Clicking it takes you to the first unread post.
If the listing is not bold, clicking it gets you the first post. To the right, the latest poster is accompanied by the date - click the date to get the most recent post.
Mere mortals only get the "Jump to new" and "Watch" buttons, not the tick and whatever that other thing on the right is in your image.
Specific examples?and just as I wrote the above I found two bold threads which when clicked took me to the first page.