Pen An Ero FormationGeologic formation in FranceSummaryThe Pen An Ero Formation is a geologic formation in France. It preserves fossils dating back to the Devonian period.Originally created by Abyssal7/25/2014, 1:44:28 AMModified10/18/2025, 8:19:27 PMContributorsAbyssalSource: WikipediaView full article↗