Previous excavations in the Katanda region of Congo yielded barbed harpoon points carved out of bone 80,000 to 90,000 years ago.
Previous excavations in nearby areas -- one dating back decades and the other just a few years ago -- turned up impressive collections of ruins from various periods.
In this and previous excavations, archaeologists said, no artifacts had been uncovered that had anything to do with China in the Han dynasty.
More teeth have since been found in Denmark, and now England, so more examples seem likely to turn up – or be recognised from previous excavations.
Previous excavations at the site have found artefacts from the iron, bronze and neolithic periods, evidence that the rocky formation has provided millennia of natural shelter for humans.
Previous excavations by the Michigan group, beginning in 2007, had uncovered a significant part of the city, including private houses, wealthy burials, city walls and a temple.
Previous excavations had yielded clay writing tablets from 1200 B.C., close to the approximate time of the supposed Trojan War, and some references to Iklaina as an administrative center associated with Pylos.
Previous excavations of other sites in South Africa, such as at Swartkrans near Johannesburg, have burned material dated to 1.5m years ago, but the techniques used to study this and other old sites do not provide conclusive evidence that the burning occurred in controlled fires.
The team dated three arm bones found at different locations within the cave during previous excavations.
Previous excavations on Newarke Street have revealed numerous Christian burial grounds near the present site.
