Homo erectus evolved around two million years ago, and was the first known human species to walk fully upright. New dating evidence shows it survived until just over 100,000 years ago on the Indonesian island of Java - long after it had vanished elsewhere.
     In the 1930s, 12 Homo erectus skull caps and two lower leg bones were found in a bone bed 20 metres above the Solo River at Ngandong in central Java. Researchers have since attempted to date the fossils, but this proved difficult because the surrounding geology is complex and details of the original excavations became confused. In the 1990s, one team came up with unexpectedly young ages of between 53,000 and 27,000 years ago.
     Now, researchers led by Prof Russell Ciochon of the University of Iowa opened up new excavations of an untouched reserve area on the terraces beside the Solo River, providing what they describe as a definitive age for the bone bed of between 117,000 and 108,000 years - the most recent known record of Homo erectus anywhere in the world.
     On other islands in South-East Asia, Homo erectus appears to have evolved into smaller forms, such as Homo floresiensis - the "Hobbit" - on Flores, and Homo luzonensis in the Philippines.
     The fossils represent a period when open woodlands were transforming into rainforest. No Homo erectus are found after this time, and there's a gap with no human activity at all until Homo sapiens arrives on Java around 39,000 years ago.

Edited from Nature, BBC (18 December 2019)