Role of gastroliths in digestion questioned

From St. Paul, Minn., at a meeting of the Society of Vertebrate Paleontology

The discovery of large, polished stones inside the body cavities of some fossils of large plant-eating dinosaurs led many paleontologists to believe that the gastroliths–Greek for “stomach stones”–aided the creatures’ digestion by grinding up tough vegetation. New analyses of the gastroliths in ostriches are casting doubt on that theory.