in "the science of discworld"[0] this is touched upon through the nice example of: T-Rex have been on the planet for a few million years, they were huge, and we

in "the science of discworld"[0] this is touched upon through the nice example of: T-Rex have been on the planet for a few million years, they were huge, and we found a handful of their fossils. It is plausible (but not probable) that a civilization of smart lizards evolved and disappeared in 100k years without leaving any trace that we could find. [0] https://en.wikipedia.org/wiki/The_Science_of_Discworld https://en.wikipedia.org/wiki/The_Science_of_Discworld