GOTHENBURG, SWEDEN—A new statistical model developed by Bettina Schulz Paulsson of the University of Gothenburg suggests that huge stone structures were first built in what is now northwestern France some 6,800 years ago, and that megalithic construction styles spread across Europe in three waves, according to a Science News report. Paulsson processed 2,410 radiocarbon dates obtained from megalith sites and even older graves and earthen monuments to develop a timeline for when 154 different megalith sites were built. She said the model indicates the first structures, which consisted of two or more standing stones topped with a third stone or a mound of earth, spread from northwest France down the Atlantic coast and into the Mediterranean, perhaps by sailors who traveled long distances and shared their style of building with the people they met along the way. The construction of passage graves, which are now found along the coastlines of Portugal, Spain, Ireland, England, Scotland, France, and Scandinavia, are thought to have been spread by seafaring traders between 6,000 and 5,500 years ago. The final phase of the spread of megalithic structures included the construction of monuments such as Stonehenge with massive boulders some 4,400 years ago, Paulsson said. For more, go to “Quarrying Stonehenge.”