The sequel to one of the best Half-Life mods has been unveiled, a new site for Natural Selection 2 is now live and features a teaser video featuring what looks like an alien triceratops called the “Onos”. Hit the jump to see the trailer.

Natural Selection 2 is described as being an immersive, online FPS that pits aliens against humans in a strategic and action-packed struggle for survival. It is a commercial sequel to the original mod with a planned fall 2009 release. If you want you can pre-order the game now which will give you access to the beta and some other special goodies if you pre-order the Special Edition.

Exciting no?