Great ideas, Peter!
*Gives Peter…*
Hey! Where’d that biscuit go?

Their shape looks quite mechanical to me atleast at first glance, but it was their placement that looked highly organic. As if someone had takend a bagful of gears and emptied it on the ground. Hm…I was hoping for something more groundbreaking. A better hoax perhaps, or having the gears placed in some sort of a coherent manner inside the rock.
Personally I’m not convinced until they dig up the TARDIS. Now a 400 million year old blue english phonebox - that would be newsworthy!

There was a place I discovered in some woods in Illinois, where a spring came out of the ground and a large patch of rocks was exposed.  The entire area of rocks, perhaps the size of a tennis court, was just a mass of fossilised crinoids rather like in those photos.  There were also tons (probably literally) of loose crinoid bits all over the place, like little polished disk-shaped agate beads.  I collected several bags of the loose bits, but I think I’ve probably lost them all since then.

If I ever pass through Illinois again, I might be tempted to find the place once more.  I still remember the general area where it was.  There was a big housing development nearby, though, so I wouldn’t be surprised if it has all been built over during the intervening years.