What in the world is this thing? The formations found in the 19th century in Nebraska resembled huge corkscrews, and locals called them the Devil's Corkscrews. Yeah, scientists knew they were fossils of some sort, but what made them: a vine, a tree root, or a worm from an ancient sea bed? Maybe a monster? These things could have been the inspiration for the movie Tremors! But if you looked at the picture and thought "spiral staircase," you'd be on the right track.
With all the different theories, it took decades for scientists to come to an agreement about what made these "Daemonelix." The final bit of evidence that confirmed the theory wasn't discovered until 1977! -via Mental Floss