Eurypterus remipes

Real Fossil - Late Silurian 422 Mya - Herkimer County New York
All arthropods have an exoskeleton. When the animal grows too large, it sheds its exoskeleton and grows a new one. Because of this, many eurypterid fossils are actually molted exoskeletons. This specimen of New York's state fossil resulted from actual deaths of two euryterids.