Among the most widely promoted examples of fossil folklore is a supposed link between the Central Asian horned dinosaur Protoceratops and the griffin, a gold-guarding mythical creature combining features of lions and birds. First proposed in the 1990s, this geomyth postulates that tales of Protoceratops fossils were transmitted westward along trade routes from Asian gold mines to inform griffin lore among the ancient Greeks. An evaluation of the Protoceratops–griffin link, however, finds it uncompelling. Not only does it ignore established histories of griffin art and myth, but no convincing connections occur between Protoceratops and central aspects of griffin lore, such as gold guarding. In fact, Protoceratops fossils occur hundreds of kilometres from the nearest gold deposits, subverting suggestions that they inspired the griffin's association with gold. Interpretations of ancient literary references to griffins as pertaining to Protoceratops are unconvincing, and suggested anatomical similarities between griffins and Protoceratops are selectively identified. We regard the Protoceratops–griffin link as an ‘ex post facto geomyth’: an effort to find significance in superficial, inconsequential readings of geological phenomena and mythology. We posit that the allure of ancient cultures sharing our modern fascination with dinosaurs has denied this idea due scepticism.