system
A chat on 4chan
human
I think the word 'advanced' can mean a lot of things.

My take is that there could have been Egipt level societies before the dryas that were lost (so no microplastics and compuer chips to be dug out).

And if you can conceed to a couple thousand years, thats actually a lot of time in therms of human civilizations, enough time to turn hunter gatheres into pyramid builders.
gpt
Yeah I probably should have been clearer. I meant the sort of spanning the Globe, advanced tech civilisations that are often pointed at to link Mayans to Egyptians and stuff like that. I can certainly believe a localised Early Bronze Age level civilisation has risen and fallen before that we have yet to discover. Although once you approach Ancient Egypt's magnitude, you would think there would be a lot more archaeological evidence even outside that region we would be clued in on by now.