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Unless the intelligent Velociraptors had a "World War 3" that featured a massive, targeted asteroid strike near what's now Mexico, I think there's geological evidence for non-intelligent causes for a lot of these. (Or, building on this article, did the Trilobite People trigger the massive Siberian lava flows that ended the Permian?)

Still a fascinating question, mind you! (But honestly, I'm dubious that anything humanity could do today would lead to a Permian-scale mass extinction. That one was remarkable.)

I doubt there wouldn't be evidence. A steel building frame probably preserves better than bone. A global population of tool making beings should at least leave some fossil evidence even if their timeline was only 30-50k years. Lastly, the distribution of natural resources might leave some evidence (like not finding ore where you would expect it).

Have you seen a steel bridge lately? They require constant maintenance to prevent them from rusting away. Even stainless steel will rust eventually. The only thing that lasts more than centuries is stone, and only the really hard stones will last for thousands of years.

The other problem is location. Humans like to build on coastlines, and coastlines shift. We have very little evidence of ice-age era settlements today, but the few sites we do know of show that there were some pretty sophisticated societies around at the time. It's very likely that there are/were more sites, but today they're under a few hundred feet of water off our coasts.

As far as natural resources: apparently there are extensive empty holes in the ground around the great lakes that used to be full of copper ore, based on what's left in the walls. So much copper ore that the mining must have gone on for centuries, or involved tens of thousands of people. No one knows who did that, but a likely possibility is the Phoenicians during the Bronze Age. So that's one example of the type of evidence you're talking about, albeit for a more recent period. To go back much further, we'd have to know what kind of resources they were after and where, and hope that the landscape hasn't changed so much that we can't recognize the evidence of resource mining.

Actually, once the frame collapses and gets covered in earth, it'll likely decay way faster than bone. Note the incredible lack of early iron age tools compared to bronze age tools.

That said, it's super unlikely that all, or even most traces of humanity will be gone. As you point out, the redistribution of resources - most specifically our landfills will probably be clear signals on the time scales of at least 10s or maybe 100s of thousands of years.

It's interesting to note that it took 30,000 - 50,000 years for the humans to develop this extremely complex society and ecosystem. Perhaps so short that when if we were destroyed this very day nothing would remain, say from nuclear war. All of our buildings would decay and there would be very little remnant in the fossil record.

That reminds me of something:

> The [Science of Discworld] also features a fictional crab civilization and the dinosaurs (both of which are wiped out by comets/asteroids colliding with the earth), before jumping ahead to when an advanced civilization (presumably humans) has evacuated the earth due to an impending natural disaster.

http://en.wikipedia.org/wiki/The_Science_of_Discworld

Anyway, I wouldn't be surprised if (for example) the field of astrobiology is thinking about what could be used as indirect proof of intelligent lifeforms tampering with an ecosystem. Also, while you are obviously are aware of this, I think it's worth emphasizing that all mass extinctions showing a similar pattern is not a proof agency.

This is exactly the scenario that was presented by Ian Malcolm in Michael Crichton's The Lost World.

A little off-topic but the fantasy series Broken Empire are set in a post-apocalyptic world similar to the one you described. When I read them I thought that was very original.