China’s famous feathered dinosaurs probably could have used down  
coats, given the chilly temperatures they lived in. By looking at  
varieties of oxygen atoms inside fossils, which can preserve  
temperature information, researchers found that northeastern China was  
unusually cold between 122 million and 130 million years ago. Mean  
temperatures averaged 10° Celsius as dinosaurs, crocodiles and other  
creatures roamed the landscape, an international team of researchers  
reports in an upcoming Proceedings of the National Academy of  
Sciences. The work could help explain why the Chinese fossils are so  
unusual. —Alexandra Witze