The rover is not on Mars. It's a hoax. It's out in some desert somewhere and the govt wants us sheeple to think we made it to Mars. The dried vegetation or dead animal you spotted would have proved this is a fabricated, staged event, so they had to hide it.
Reasons? USA can boast we are the first to get there. Make China, Russia etc spends billions trying to get there too. They must try now, to prove they have the engineering, finances, and skills to compete.
Second, government big-shots siphon billions off of the NASA budget for their buddies (contracts for parts, etc.)
Third, keep the stupid American public busy while they steal the country while nobody is watching.
Yes, I am a conspiracy theorist. It's a hoax, and you busted them.
Dan