E-Mail IMAGE: A cliff in Jameson Land Basin in central East Greenland, the northernmost site where sauropodomorph fossils are found. The labels point out several series of layers that helped the researchers... view more Credit: Lars Clemmensen A new paper refines estimates of when herbivorous dinosaurs must have traversed North America on a northerly trek to reach Greenland, and points out an intriguing climatic phenomenon that may have helped them along the journey. The study, published today in Proceedings of the National Academy of Sciences, is authored by Dennis Kent, adjunct research scientist at Columbia University's Lamont-Doherty Earth Observatory, and Lars Clemmensen from the University of Copenhagen.