I commented this when the last poster made this claim a month back: Sharks are older than most of the current, eaily-visible rings of Saturn. The E-ring is primary composed of material ejected from Enceladus, and there is no indication I have found which would suggest that the hydrothermal processes which cause the jets are anything new. Additionally, just because most of Saturn's current rings were formed more-recently doesn't mean there weren't rings back then. The gas giants have hundreds of moons, and they certainly used to have more. I think it is an undeniable, generally - accepted fact that the gas giants have all had significant rings at some point in the past (and they all, in fact, do have rings, just not all as spectacular as Saturn's current ones.