Their fossils are locally common but have been found nowhere else on Earth. That’s why the Tully Monster (Tullimonstrum gregarium), a slender soft-bodied creature with a long, narrow snout and sensory organs (primitive eyes) set away from the body on stalks, has come to represent Illinois as the “State Fossil.” Francis Tully found the first one in 1958. He took it to experts at the Field Museum of Natural History in Chicago for identification, but the scientists were stumped. Museum staff with a sense of humor nicknamed it the “Tully Monster.”