Embryos Dating Back 500 Million Years Revealed With X-Rays National Geographic - August 9, 2006

Scientists used the world's largest microscope to take this image of an ancient wormlike creature called a penis worm. The high level of detail in this and other images will give researchers important clues that will help determine how closely the animals are related to modern species.

Swedish scientists find half-billion-year-old droppings from aquatic worm PhysOrg - April 13, 2006
Swedish scientists have found half-billion-year-old droppings thought to be from an aquatic worm and hope the discovery will contribute to the understanding of prehistoric ecosystems.