An astonishing trove of century-old photographs of the Rocky Mountains shows those rugged symbols of permanence and endurance are just as mutable as anything else.

Ancient flying reptiles, commonly called pterodactyls, were more diverse than first thought, according to new research by an international group of paleontologists.

Researchers studying the remains of an enormous dinosaur - a creature that was bigger than seven bull elephants - have given it an equally colossal name: Dreadnoughtus, or "fearing nothing."