The Topix Dinosaur Forum (also known as the Prehistopian Empire, when referring to the original Topix Dinosaur Forum, as well as the various spin-off forums) is an Internet discussion forum about, well, dinosaurs. It can be found here: http://www.topix.com/forum/science/dinosaurs/
The forum has a long and convoluted history. It was attacked by trolls numerous times, and many violent wars were fought between the trolls and the contributors, eventually leading to the de facto abandonment of the forum by the contributors in 2013.
The Dinosaur Forum first began to attract a substantial number of users around 2006. Beginning in 2007, a few minor trolls harassed the forum, but it remained mostly troll-free. However, in 2008, that all changed when a new troll named Ethan Dino arrived and began to attack the forum. He created many accounts to destabilize the forum, and posted racist and offensive comments. Ethan Dino remained on the forum until 2011, when he finally left.
However, in late 2009, a new troll named Pincus Shain arrived. He was by far the most powerful troll that Topix had ever seen up until that point. He created a massive troll empire which he named Troll Topia, and managed to assert his dominance over the entire forum. A team of contributors led by Ernst Udet secretly developed a plan to oust Shain and topple his empire. But before they could put their plan into action, Shain himself mysteriously disbanded his empire in June 2010, and left the forum.
Shain's empire caused some of the contributors to leave the Topix Dinosaur Forum, and start new forums of their own. Perhaps the most popular of these forums was Prehistopia, which was created by Spinosaur King. Prehistopia soon became very popular, and many of the contributors flocked there to escape the troll-infested Topix Dinosaur Forum. For a while, Prehistopia seemed to be flourishing, and it was a very peaceful web site, with no interference from trolls, whatsoever.
However, on July 29, 2010, all of that changed. On that day, a hacker named Aequitas the Eliberator hacked Prehistopia and deleted all of the accounts and threads contained within it, effectively rendering it useless. Spinosaur King tried desperately to bring Prehistopia back, but to no avail. It was gone.
After the Prehistopia incident, the contributors started another forum called Imperial Palace. Unlike the other two forums, trolls have very rarely succeeded in attacking Imperial Palace, and it is now the main forum for the Topix Dinosaur Forum community.
Meanwhile, back at the original Topix Dinosaur Forum, things continued to go downhill, and there were very few active contributors on the site. In September 2013, Raptorial Hawk declared that the Topix Dinosaur Forum was "dead", and encouraged the few remaining contributors to move to Imperial Palace. However, some of the contributors still remained at the original Topix Dinosaur Forum, and the forum itself is still active to this very day — albeit on a greatly-reduced scale.