I was wondering how is this mesh rigged? http://www.gfx-3d-model.com/category/3d-characters/ the third one from the top,the SWAT officer guy.When I open it up,I don't see any bones or keyframes,but when I move the timeline,it rotates all it's limbs.I saw the same kind of rotations on many youtube clips where the mesh rotates its head,shoulders,then elbows,wrists,back,etc.Can someone explain to me what/how this phenomenom is used?

many youtube clips

Can you post such a clip, I dno't own max to test it out what you mean.