Are there any trusses that are supported strictly by the wood itself without any mechanical connections such as brackets?
Most truss-to-bearing connections do not require metal connectors. Instead, the trusses bear directly on the wall, beam, header, etc. that is supporting them. In this case, nails driven in at an angle (toenails) are sufficient to keep the trusses in place. If there are uplift forces at the bearing point that exceed gravity loads, then the truss must be held down with a connector.