Clearly inspired by the anatomy of a foetus or stillborn to me. The stripes in the arms could represent fasciae of muscles. Eye and nose cavities in the skull can be spotted easily in the figure.

Not need to use a supernatural explanation for something that can be explained by normal events.

https://www.darwinandwallace.com/products/fetal-human-skelet...

A big difference is that we know for a fact that psychedelic mushrooms were around back then -- they didn't spring into existence in the last couple thousand years.

Sure but rock art is extremely extremely hard to interpret. The foremost world experts in it. Do not make such claims. Unless there was a mushroom literally found at the site how can a serious person make such a bold claim.

(Even if a mushroom or proof of its usage was found nearby. Rock art specialists have found that dating rock art by the surrounding context is not the correct technique. As newer methodology has found that the surrounding context can lead to dating thousands of years off. It’s best to date the art directly)

It's not like we can find fossilized shrooms that easily. They decompose things as part of their food source just as they in turn decompose things. I grow shrooms, and they don't have a shelf life for more than 3-12 days depending upon the variety of edible if they're not dried out. Reishi notwithstanding.

I'm not saying that this should be thought of as the only interpretation, only that it seems more likely than "aliens". And in the pictures provided by the article, one of them clearly depicts mushrooms