Nonmarine Diplocraterion luniforme (Blanckenhorn 1916) from the hasandong formation (Cretaceous) of the Jinju area, Korea

Diplocraterion luniforme occurs abundantly in the Cretaceous Hasandong Formation of the Jinju area, Korea. The Hasandong Formation consists of fluvial deposits mainly composed of sandstone, siltstone, mudstone and shale. The formation contains freshwater bivalves such as Trigonioides sp. and Plicatounio sp., fossil tree stumps, carbonized wood, stromatolites, caliche nodules, current ripples and desiccation cracks. The trace fossils Planolites ichnosp., Skolithos ichnosp. and Taeni‐ium ichnosp. are also commonly observed. Diplocraterion luniforme occurs in the gray shale which is considered to have been deposited in floodplain lake environments. This report represents an unusual record of a nonmarine occurrence of Diplocraterion, which has previously been generally regarded as a diagnostic marine trace fossil.