How old is Civilization on Earth

[Ahabstar]

I have a "thing" for fossils, and have spent many an hour hunting them down. Years ago, when I lived in Ohio, I found one in a fine-grained sandstone that perplexed me. I found it about half-way between Cleveland and Akron, in a bitty little place named "Boston Heights" (precise location of find is: 41°16'21.66" N  81°31'28.79" W ). It appeared to me to be the shank of a machine screw, about a #8 screw, without the screw head to positively identify it, and it was embedded in the sandstone. Oddly, it was black in color, as if it were phosphate-coated, and the "threads", or whatever they were, were exceptionally regular in spacing, which is what gave it the appearance of a machine screw rather than a biologically created item.

I've often wondered about that fossilized screw.


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If it looked like this it is a Sea Lily stem.