This beautiful slab was cut from the center section of a petrified pepperwood tree. It contains numerous worm or arthropod (likely insect) galleries containing coprolites of various sizes. When the trees fell into the shallow lakes, some 50 million years ago, they often became covered in algae. This algae provided a wonderful habitat for tiny seed shrimp called ostracods. With a microscope, their tiny shells can be seen within the fossilized algae surrounding the wood (see the 3rd photo).