Rome, June 15 - Italian and Eritrean researchers on Wednesday found the first traces of 'homo erectus', a key predecessor of modern man. The footprints, left 800,000 years ago in the sand of a lake that is now part of an Eritrean desert, were found by palaeontologists from Rome's La Sapienza University and the National Museum of Eritrea, at the Aalad-Amo site in the east of the country. Dig coordinator Alfredo Coppa said the footprints would likely say a lot about a key species in the history of human evolution.