A human parietal fossil found at the Shuidonggou site, Ningxia, China

Abstract

The morphological features of the first human parietal fossil found at the Shuidonggou site of Ningxia, China are described and compared with other specimens. Our results show that most of the features of the Shuidonggou parietal resemble those of modern humans. On the other hand, this specimen was found in situ adjacent to the erosional surface of the late Pleistocene stratum and exhibits a certain degree of fossilization. There are two features which are different from modern humans and similar to those of fossil hominids. One of the features is the strong ridges between the striae parietalis suggesting that the temporalis muscles were more developed than in modern humans. The second feature is the lack of a sigmoid sulcus at the mastoid angle of the Shuidonggou parietal which is similar to the situation seen in Homo erectus of Zhoukoudian. Given the similarities of many morphological features between late Pleistocene and modern humans, it is impossible to set the age or evolutionary status of the fossil accurately just from skeletal morphology of a fragmentary parietal. Nevertheless, taking the specimen’s fossilization and the background information of the site into consideration, we believe that the parietal likely comes from the late Pleistocene human populations that lived in this area.