[Vesparado]

I can see it already: “Paleo Skis” modeled after what they’ve recovered from the ice!

[TXnMA]

There was a well-known practice of putting skins -- with the fur facing backward -- on early cross-country skis. The fur provided traction on the "power push", and "glided" forward almost effortlessly on the forward "slide" step.

I have little doubt that the fur worked much better than the "sawtooth" ridges on modern CC skis -- but, I doubt that it lasted as long...