A team of archaeologists have unearthed the world's oldest evidence of surgical amputation. The skeletal remains of a young hunter-gatherer whose lower left leg was amputated by a skilled prehistoric surgeon date back 31,000 years ago. The new finding was brought to light during an archaeological excavation at Liang Tebo which is a limestone cave in the remote Sangkulirang-Mangkalihat region of eastern Kalimantan, the Indonesian portion of Borneo and is accessible only by boat at certain times of the year. The team of Indonesian and Australian archaeologists were co-led by Griffith University academics.The discovery, published in Nature, is thought to be the earliest known evidence for a complex medical act re-dating other instances of stone age 'operations' found at sites across Eurasia by tens of thousands of years. Analysis by palaeopathologist Dr Melandri Vlok (University of Sydney) confirmed tell-tale bony growths related to healing, suggesting the limb was surgically amputated several years earlier when the individual was a child. “It was a huge surprise that this ancient forager survived a very serious and life-threatening childhood operation, and that they then lived for years in mountainous terrain with altered mobility.” Dr Vlok said. Previously, archaeological research across Eurasia and the Americas had uncovered human bones that bore signs of prehistoric surgeries including holes drilled in skulls (trepanation). Up until now, the oldest evidence yet revealed for amputation surgery had comprised the 7,000-year-old skeleton of an elderly male Stone Age farmer from France whose left forearm had been carefully amputated just above the elbow.