Megarachne
Fossils of Megarachne have been discovered in deposits of Late Carboniferous age, from the Gzhelian stage, in San Luis, Argentina. If the original identification as a spider had been correct, Megarchne would have been the largest known spider to have ever lived. The fossil preserves the carapace, the first two tergites, three partial appendages and what is possibly a coxa.
