The clue to the origin of Homo floresiensis comes from previous work suggestive of the presence on Flores of earlier, full-sized prehumans. Michael Morwood, of the University of New England, codirector of the excavation, is working closely with his Indonesian colleague R. P. Soejono, of the Indonesian Centre for Archaeology in Jakarta, whose team discovered the skeleton. In the mid-1990s Morwood and his colleagues unearthed stone tools on the island dating back 800,000 years. The implication was that the toolmakers, presumably Homo erectus, were capable of navigating the open sea. It is possible that once marooned on Flores, a population of Homo erectus set its own evolutionary course, changing into Homo floresiensis.