Isotopes in teeth suggest two megalithic cultures were separate groups
(PHYSorg.com Archaeology & Fossils)

A team of researchers from the U.K., Belgium and Spain has found evidence that two groups of people in Late Neolithic Europe living approximately 5,500 years ago belonged to two distinct communities. In their paper published in the journal Science Advances, the group describes their study of isotopes from two burial sites and what they found.