Twin Ritual.

From ScienceShots:

Anthropologists working in eastern Austria have uncovered the bodies of three infants buried by hunter gatherers 27,000 years ago. Two appear to be twins because they were buried together and have leg bones that are the same length. Although babies buried by Neandertals and modern humans have been found that date farther back, the new bodies are unusual in that they are adorned with ivory beads, red ochre, and mammoth bone. That makes this the oldest evidence of the ornate decoration of infants in the human fossil record, indicating a shift to a more modern social behavior in this Stone Age culture.