human remains at Dawenkou sites in southern Shandong revealed that the diet of upper-class Dawenkou individuals consisted mainly of rice, while ordinary individuals ate primarily millet. The Dawenkou people successfully domesticated chicken, dogs, pigs and cattle, but no evidence of horse domestication was found. Pig remains are by far most abundant, accounting for about 85% of the total, and are thought to be the most important domesticated animal. Pig remains were also found in Dawenkou burials also highlighting their importance. Seafood was also an important staple of the Dawenkou diet. Fish and various shellfish mounds have been found in the early periods indicating that they were important food sources. Although these piles became less frequent in the later stages, seafood remained an important part of the diet. Culture Dawenkou's inhabitants were one of the earliest practitioners of trepanation in prehistoric China. A skull of a Dawenkou man dating to 3000 BC was found with severe head injuries which appeared to have been remedied by this primitive surgery. Alligator hide drums have also been found in Dawenkou sites. Interactions with other cultures The Dawenkou interacted extensively with the Yangshao culture. "For two and a half millennia of its existence the Dawenkou was, however, in a dynamic interchange with the Yangshao Culture, in which process of interaction it sometimes had the lead role, notably in generating Longshan. Scholars have also noted similarities between the Dawenkou and the Liangzhu culture as well as the related cultures of the Yantze River basin. According to some scholars, the Dawenkou culture may have a link with a pre-Austronesian language. Other researchers also note a similarity between Dawenkou inhabitants and modern Austronesian people in cultural practices such as tooth avulsion and architecture. However, the Dawenkou appeared to be genetically distinct from the pre-Austronesian cultures to their south. Physical characteristics The physical similarity of the Jiahu people to the later Dawenkou (2600 BC±4300 BC) indicates that the Dawenkou might have descended from the Jiahu, following a slow migration along the middle and lower reaches of the Huai river and the Hanshui valley. Other scholars have also speculated that the Dawenkou originate in nearby regions to the south. The Dawenkou culture descends from the Beixin culture, but is deeply influenced by the northward expanding Longqiuzhuang culture located between the Yangtze and Huai rivers. The people of Dawenkou exhibited a primarily Sinodont dental pattern. The Dawenkou were also physically dissimilar