“Tertiary Dinosaurs” in the Nanxiong Basin, Southern China, Are Reworked from the Cretaceous

Abstract

Abstract The Nanxiong and Shanghu Formations of southeastern China span the KT boundary interval and preserve an important paleontological record. A 1285‐m section across the KT boundary was measured, and lithological units were documented and sampled. Strata were deposited in alluvial fan/playa mudflat environments in a highly seasonal, semiarid climate. Previous workers placed the KT boundary at the Nanxiong/Shanghu formational contact. The uppermost Nanxiong and lowermost Shanghu Formations contain an assemblage of dinosaur egg fragments and Tertiary fossils, which led to the notion that dinosaurs survived into the Paleocene. On the basis of our results, we argue that the mixed KT assemblage is a result of debris flows reworking Cretaceous fossils. Depositional environments and paleoclimate did not change significantly across the KT boundary.