Caption Above: Ortelius's 1658 map of Iceland showing various mythological sea creatures. Below, a detail of a sea creature labelled H, ‘the greatest of whales’ which could not chase fish but ...

Their results dated the parchment to within 11 years of 1434, the time frame noted by the map's defenders. But the test merely proved that the parchment was medieval, not the ink of the map itself.