Digestive problems such as cramping or diarrhea could signal irritable bowel syndrome. Learn more about IBS and how to control discomfort. Full Story ››
National Geographic Explorer-in-Residence Paul Sereno, enveloped by the jaws of SuperCroc, holds the fossil head of DogCroc, which lived in the Sahara when the 8-ton SuperCroc did. View Slideshow ››