Wikipedia
Teouma is a major archaeological site on the island of Éfaté in Vanuatu. The site contains the oldest known cemetery within the Pacific Islands, and has been important in the gathering of information relating to the Lapita people of the ninth and tenth centuries BC.
In late 2003, 26 inhumations consisting of 36 individuals were found in the largest-known cemetery located on the south coast of Éfaté Island in Vanuatu in the Pacific. The cemetery is thought to be between approximately 3200 and 3000 years old. One common factor includes red pottery fragments with containing intricate designs. Many of the individuals were buried in different positions. However, one consistent feature of the burials included the removal of the skull after the decomposition of the periodontal ligaments. After the burial, these skulls were replaced with cone shell rings. This demonstrates a ceremonial culture.
Isotope analysis was done to the excavated individuals to determine the characteristics of human migration in the pacific during this time period. Researchers were able to analyze isotopes of 17 of the individuals. Subsequently, they found 4 of the individuals with different isotope levels. Thus, it is believed that these four individuals were immigrants, and in addition to having different isotope levels, they may have been different culturally as well.