Is there any checked case of "involution"?
"Exactly the same" probably doesn't fly, just because there is so much possible variation, but for a fairly obvious example, consider birds.  Their ancestors evolved flight: some modern-day birds (ostriches, emus, kiwis, &amp;c) have lost that ability, though their vestigal wings haven't re-evolved into legs.  But consider the evolutionary link between birds and theropod dinosaurs, and how many of those (e.g. T. rex) had vestigal forelimbs.

Another example would be dolphins and ichthyosaurs, which both independently "involved" from land-dwelling creatures back to a form that's similar to the ancestral fish.

But of course neither of these are really "involution" in the sense of reversing an evolutionary path.  They are cases of organisms exploring new evolutionary paths, where the environmental pressures (such as need for streamlining to move efficiently in water) cause them to resemble some ancestral form.