. . . just published in Science. Heh.

"It's a puzzle, a 'conundrum' is the word we like to use," Oglesby said. "And in the Science paper, we're not solving the conundrum, we're raising the conundrum."

The root of the conundrum is Loope's ongoing research in the Colorado Plateau that began when he was working on his doctorate at the University of Wyoming in the early 1980s. A sedimentologist and an expert on dune formation, he eventually saw that from central Wyoming into central Utah, ancient dunes preserved in the region's 200 million- to 300-hundred-million-year-old sandstone formations all faced southwest, meaning that the winds over that extensive area were almost constantly from the northeast. As his study progressed, he discovered that the direction of the dunes shifted to the southeast in what is now southern Utah, meaning the wind direction shifted to the northwest. What's more, those prevailing winds were consistent over the entire 100 million years in question and the shift in wind direction could only have occurred at the equator.

"I thought that was very curious," Loope said. "It didn't seem to fit with what we think we know about where the continents were."