...not that we saw any fauna – nary an insect, let alone anything furry, scaly, feathered or clawed...
It could be that you just couldn't see them. There could well be tribes of very, very tiny little critters who have been lost in the desert for 40 years. It's all a matter of scale. A very small scale
Bwahaha! Perhaps their leader could find some stone tablets on top of one of those formations.