(Left image) Mars Skulll - Sol 482 - This humanoid skull may well be part of a crash site. It has what could be interprated as part of the cockpit iether side of him or perhaps the protective head parts of an ejector seat.
(Central skull image) This "Gusev Crater Skull" may well be humanoid but with a split mandible.
It is common for the lower jaw bone to be broken in such a way. In fact it's rare to find one intact. It could even be a protective helmet with breathing gear below.
(Left image) This looks like part of an aileron in the top centre of this image. It has what look like supporting struts.