Excavations at the eastern end of the cave's main gallery, at the base of the sloped entrance, were conducted by a team of American, French and Laotian researchers starting in 2009. The first fossil find, a hominin skull dubbed
TPL1, was recovered at a depth of in December 2009. A mandible,
TPL2, was found the following year at a depth of .
Radiocarbon and
luminescence dating of the sediments established a minimum age of 51,000 to 46,000 years, and direct
uranium-thorium dating of the fossils indicated a maximum age of 63,000 years. In 2013, researchers recovered the partial mandible of a third fossil find,
TPL3, at a depth of , from the same area as the previous finds. The bone fragment likely belonged to an adult. Like
TPL2,
TPL3 exhibits a mix of archaic and anatomically modern human traits, exhibiting modern human features such as having a developed chin but not having a robust mandibular corpus; however,
TPL3 also retains archaic human features such as having a broad anterior mandibular arch. Luminescence dating of the
TPL3 sediment layer provides a date range from around 70,000 to 48,000 years old.
Significance The timing of modern human migration from Africa to East Asia is not known with certainty; because bone is poorly preserved in tropical climates, human fossils from the region are rare. Recent discoveries in China, the Philippines, Sri Lanka and Australia had previously established that archaic human fossils were present between 125,000 and 100,000 BP, and those of modern humans from about 40,000 BP. The discovery of the fully modern
TPL1 specimen was therefore considered a major discovery because it filled in a 60,000-year gap in the fossil record, demonstrating the presence of modern humans in Southeast Asia from at least 60,000 BP. Additionally, as Tam Pa Ling lies a thousand miles inland, the finds challenged previous assumptions that humans migrated out of Africa by following coastlines. They suggest that the migration may also have proceeded along river valleys, which served as natural corridors through the continent. The fossils were temporarily removed to the United States for study by
paleoanthropologist Laura Shackleford, Fabrice Demeter and the team. In April 2016 they were returned to Laos, and are now housed in a new building of the
Lao National Museum in
Vientiane. ==See also==