4,300-year-old bodies found with extra skulls in their grave in California – with some showing signs of bizarre burial rituals

Archaeologists have found evidence of macabre practices involving severed heads and polished skull caps on the site of an ancient cemetery in central California.

When excavating a Marsh Creek area in northern California, researchers found eight graves in which ‘ trophy heads ‘ seemed to have been buried alongside bodies of community members.

Ancient warriors took ‘ Trophy heads ‘ to mark victories and killings. A further seven skeletons with their heads missing were discovered. But rather than being used by warriors to take into the next world as trophies, analysis of the bones suggests that the extra skulls may have belonged to the ancestors of the buried people. In fact, experts believe that the skulls in the graves may have belonged to the people’s mothers.

Dr Jelmer Eerkens from the University of California is leading the excavation of Marsh Creek. The site borders the northeastern edge of the Diablo Range along the creek, which is a seasonal stream that starts near to Mount Diablo’s eastern summit and flows into the California Delta.

There have been nearly 500 burials on the site, and although radiocarbon dating has shown that the area has been inhabited for at least 7,000 years, the burials themselves have been made more recently-between 4,300 and 2,950 years ago.

‘Head taking is a powerful image in human societies, both today and in the past,’ explained Dr Eerken. ‘Trophy heads figure prominently in the iconography of several ancient chiefdoms, states and empires, both in the Americas and beyond. Indeed, human trophy taking is present in nearly every major culture area of the Americas, except Patagonia,’ and he added his excavations provided a good opportunity to see if the heads in the Californian graves were trophies or not.

Burial 107 is an adult male aged between 35 and 45 at the time of his death.  He was buried in with his head pointing south in a pit with two other males, and aside from a partially healed jawbone fracture, there was no evidence of physical trauma on the skeleton.

In his grave the researchers found a skull cap – or calotte – covered in red ochre, placed next to his right arm. The calotte was taken from an adolescent or young adult, had been cut near part of the skull known as the superciliary arches, or brow bone, and it had ‘highly polished edges.’

The archaeologists also discovered a pointed bone fragment and a serpentine phallic charmstone fragment in this grave. Of the 480 individuals identified during excavation, 15 were found to display unusual burial practices with respect to extra skulls and severed heads. Eight bodies were interred with an extra skull and seven were buried missing their skull.

In each case, the extra skull was discovered next to the head of the main burial, with the exception of one, where the extra skull was found near the skeleton’s abdomen.  There was no evidence of trauma on any of the extra skulls, suggesting they weren’t removed violently, although three contained traces of red ochre.

Neolithic burials were said to have used red ochre pigments to symbolise ritual rebirths, due to the similarity in colour to the blood, and it is likely the burials from the Early Period of California used the pigments in a similar way.

Fourteen of the 15 individuals with special burial treatment were adults at the time of death, while the age of one individual is unknown.

For the most recent study, Dr Eerkens and his team paid particular interest to three of these burials – labelled burials 107, 109, and 137.

Burial 109 is an adult female who was over 35 at the time of her death. In her grave, the researchers found a skull next to her head which is believed to have come from another 35-year-old. While burial 137 is an adult male who was over 40 at the time of his death, he was found in the same pit as four other adults along with a highly polished calotte. This calotte was so intact the researchers even believe it could have been used as a small bowl for liquids.

The researchers don’t yet know what significance the Californian skull caps were to this ancient group, but they were likely part of some religious burial ritual, used with the red ochre. From these three burials, the researchers analysed bone fragments and teeth samples in search of isotopes of strontium. They then compared them to samples taken from 200 other skeletons found on the site.

Strontium is used to determine where a person was born, where they lived and it can reveal clues about their diet. This isotope data suggested that the skeletons lacking skulls, as well as those containing an extra skull ‘completely overlap’ with other people buried at the site. This means they were all born and lived in a similar location, and they weren’t what the researchers described as ‘isotopically distinct’.

If the people whose skulls had been removed had travelled to the site during the battle, and were killed and buried there, they would have different isotopic signatures. This would also be the case if the ‘trophy heads’ were taken during a raid of a distant village, for example. Furthermore, data from teeth of four individuals buried with extra skulls also showed local signatures suggesting they were born and raised near the site.

All of this analysis led the researchers to dismiss the ‘trophy head’ theory and instead claim the extra skulls were more consistent with the ‘ancestor veneration’ theory. Veneration is the act of honouring a person after they have died. It is based on the beliefs that the dead continue to live on spiritually, and by burying the remains of ancestors with the recently deceased can help them to journey to the next world, or can bring fortune to the group as a whole.

In the case of the Californian skeletons, the researchers believe that young children whose mother had died, yet they survived into adulthood, for example, may have been ‘reunited’ with remains of their relatives when they eventually died.

Eerkens and his colleagues report their findings in the journal American Antiquity.