+1 in general that anthropic bias is strong, but it cuts both ways, even in relatively hard nosed statistical models (@see Drake equation vs Rare Earth hypothesis). Truth is, there are a ton of factors we just can't observe (yet?) that play a big part. For example, since the rare earth hypothesis was published, we know a lot more about exoplanets, and earth-range size in the habitable zone of a stable star and galaxy appears much more common than we thought. But we don't know if plate tectonics are really required, or gas giant "vacuum cleaner" planets int he same system, or even oxygen. But we do know that the minimum value for intelligent species is at least 1, because we exist.

For me, it's carl sagan's "invisible dragon" comparison that sticks in the back of my head. If there's intelligent life out there (or in earth's ancient past) but there's no physical way to detect or know it... Then like the invisible dragon in mu garage, it's the same as not existing.

Maybe we'll develop new techniques and gather new evidence, but until we figure out how to bend spacetime for FTL anything, or find clear evidence, we should act as if it isn't/wasn't there.

So TFA says that 55M years ago there was a climate fluctuation that looks similar to the anthropocene one. Good start. But interpretation of ancient stories across cultures is practically the definition of anthropic bias. We have to wait until there is real evidence that the temperatuee bump was dragonfire and not my heating system acting up, to ascribe cause.