Oh, brother... You’re off by EIGHT THOUSAND years on the age; amanita muscaria doesn’t have red bands; Since the Sphinz nor Egypt existed in the last ice age, amanita muscaria doesn’t grow anywhere near Egypt; and you’re the number one hit on the internet for suggesting that the Sphinx ever had red paint.
The "bottom" or base is the remains of quarrying operations. The stone masons left the substrata in place under the windblown rock. At some point the material was pointed up and finished to look like a crouched lion.
The head has pretty much the same shape that it had before the quarry was started. It may have initially had the face of a lion, and maybe not. Whatever it had a face was carved into it, and that's kind of what you see today ~ except that French or Turkish soldiers fired a cannon into it.
It's a very complex pile of stone. Samples taken at different points yield different ages of first exposure.
The head was originally banded with red stripes. The artists painted white dots on the stripes.
From the rear the head looks like a mushroom.
I did not say the Sphinx head was painted red ~ but that it had red stripes. There is a report on the net to that effect. It's based on a study done by an archaeologist. The stripes also have white dots.
Amanita has most of its red dots in a band anyway. Regarding dating, the Sahara was in a pluvial right up to the beginning of Egyptian civilization in upper Egypt. The pluvial ended. Everybody moved out of the desert to the river or South to wetter areas in Africa.
Did amanita grow in Egypt or nearby in those times? Frankly, I don't know, and haven't encountered any studies that say that it did. On the other hand, it was a source of dope and all it took was one guy who'd been to the Alps or other mountains in Europe, and he'd know what it looked like. Did people visit those mountains? See Oetzi