In a converted shipping container in downtown Rio de Janeiro, Claudio Prado de Mello gingerly lifted an ivory-handled toothbrush. The boar's hair bristles were gone, but the 19th-century French inscription was perfectly legible: "His Majesty, Emperor of Brazil."
This is an odd place for a treasure hunt. But here, below a busy highway overpass, behind a commuter train station, Brazilian archaeology is undergoing something of a renewal.
Prado's team of investigators is combing the rubble from the building site of a new metro station, one of many public works the city is raising to groom for the 2016 Summer Olympics.