The "Paleolithic Diet" has come in and out of fashion since the 1970s. Its adherents eat mostly grilled meat, fish, fruit, vegetables and nuts—supposedly the only foods available to our ancient ancestors. But new research suggests that cavemen indulged in richer fare as well, at least when such victuals had a ritual significance.

A group of archeologists found the remains of a 7700-year-old aurochs barbecue by a river in the Netherlands. (Aurochs are horned ancestors of the domesticated cow; they've been extinct for 400 years.) Analysis of the remains revealed a complex set of rituals surrounding the caveman meal. The group of hunters that caught and killed the aurochs (using a flint ax) first sucked the fatty marrow from the aurochs' bones, then grilled the beast's ribs at the site of the killing. They brought the rest of the meat—scraped scrupulously from the bones—back to their settlement.

The archeologists said that the feast took place 1000 years before agriculture came to the Netherlands; the settlement the hunters came from must have survived exclusively on the food they hunted and gathered.