In a really small room in a really big house, archaeologists found the body of a 40-year-old man. They knew he was special. He was buried with a conch shell trumpet and large shells from the Pacific coast, far from this crypt in the 650-room building known as Pueblo Bonito in what is now called Chaco Canyon, in New Mexico. He was adorned with more than 11,000 beads and pendants made of turquoise and more than 3,000 made of shell. But if he was special, he was just the bottom layer.

On top of him was a two-foot layer of sand, another body, wooden planks and then 12 more bodies, the bones mixed together. They were special, too. Flutes, ceremonial staffs, more turquoise, stores of ceramic vessels, remains of South American parrots and jewelry were found nearby. The elite group of 14 had been buried in the same tiny room over the course of 330 years, starting around the year 800. In a study published Tuesday in Nature Communications, scientists say they were all related to the same female ancestor, which could provide clues to the power structure of the ancient society that lived in Chaco Canyon.

Starting in the ninth century, a large, complex society grew in Chaco Canyon, with small scattered settlements, grand apartments, irrigation systems and connecting roads. Since archaeologists stumbled upon these structures in the late 1800s, they’ve questioned how power was organized in Chacoan society. Was the community totally egalitarian? Did it have a single ruler? Did matrilineal family groups control ritual sources of power? Did associations of unrelated individuals, each led by the most capable, take charge?