Thousands of human skeletal remains have been found with brain tissue that remained unexpectedly intact. The discoveries are unusual because soft tissue generally breaks down long before bones are recovered.

Scientists have now examined the recurring pattern behind these preserved brains and may have identified why some tissue avoided decay for thousands of years. Their work offers a possible explanation for a long-standing mystery in human remains research.

The findings could help researchers better understand the conditions that allow brain tissue to survive when the rest of the body has decomposed. They also add to growing scientific knowledge about how ancient human remains are preserved.