Yeah true. You're not gonna find those though, as they would have been weathered away a long time ago, unless you could investigate the bottom of the planet, maybe the marks would remain there. I think though, that someone could still come up with a plausible theory of the birth of our solar system and our planet, just simply based on the theories FE has at present. Yeah I know, it obviously can't be completely conclusive as you don't know everything about the planet. But in the mean time I should think people could take this spinning/shearing theory, assume that there would be marks if they hadn't been eroded away, and develop the idea.