[darkmighty]

I find the bearing more significant than the wheel: without a good bearing its utility is limited. They have a rich history it seems:

https://en.wikipedia.org/wiki/Bearing_(mechanical)#History

[raverbashing]

True, but to invent the bearing you need to invent the wheel first

[starbeast]

No you don't. Rolling logs as a linear bearing for launching boats, with people carrying the logs to the front from the back as the boat passes over, almost certainly preceded the wheel.