Sailing stone track discovered `hiding in plain sight` in dinosaur fossil
(PHYSorg.com Archaeology & Fossils)

A sandstone slab prized for its detailed dinosaur footprints may also contain the track of a sailing stone or `walking rock.` Paleontologist Paul Olsen from Lamont-Doherty Earth Observatory announced this discovery in a presentation at the meeting of the American Geophysical Union on Monday. He and his colleagues think the trail of the walking rock is evidence of a brief freezing event in the tropics some 200 million years ago-the first evidence that volcanic winters reached into the humid tropics during the dawn of the dinosaur age.