A bit later, he analyzes the legend of St. Patrick of Ireland and presents some interesting results. Tylor suggests that the story of St. Patrick driving the snakes out of Ireland is the result of the re-localization of Greco-Roman myths in Ireland to explain fossils!
Tylor writes that Aelian described the ground of Crete as being poisonous to snakes by the will of Zeus (On Animals 5.2), and that St. Honoratus had driven the snakes out of an island near Cannes centuries before (Acta Sanctorum, Jan. 16). “What is left after these deductions is a philosophic myth accounting for the existence of fossil ammonites as being petrified snakes, to which myth a historical position is given by claiming it as a miracle, and ascribing it to St. Patrick.”
This is confirmed by a weird passage in Andrew Boorde’s description of Ireland written in the age of Henry VIII: “I haue sene stones the whiche haue had the forme and shap of a snake and other venimus wormes. And the people of the countre sayth that suche stones were wormes, and they were turned into stones by the power of God and the prayers of saynt Patryk” (Introduction of Knowledge, 1870 reprint, p. 133).
Even if this were not the origin of the St. Patrick legend, Boorde’s testimony certainly shows, once again, that any stimulus can serve as the focal point for an elaborate myth, meaning that there is no reason to suggest aliens when fossil cephalopod mollusks (ammonites) will do.