The oldest humanoid skeleton ever found has been taken out of Ethiopia for a controversial tour of American museums.
The public has only seen the real Lucy remains twice in Ethiopia
Archaeologists say the 3.2m-year-old remains - known as Lucy - are far too fragile to be moved around.
But Ethiopia said it would use cash raised from the six-year tour to fund museums back home and build new ones.
The discovery of Lucy in north-eastern Ethiopia in 1974 led scientists to rethink existing theories about early human evolution.
The fossilised partial skeleton of what was once a 3.5ft (1m) tall adult was the earliest known hominid, Australopithecus afarensis.
The real Lucy remains have only been exhibited publicly in Ethiopia twice.
A replica is on display at the Natural History Museum in the capital Addis Ababa.
Zelalem Assefa, an Ethiopian who works at the Smithsonian Institution, a prestigious US research institute, said in Addis Ababa he disapproved of the tour.
He told the Associated Press news agency: "These are original, irreplaceable materials. These are things you don't gamble with."
The BBC's Elizabeth Blunt in Addis Ababa said Ethiopian exiles in the US have mounted a vociferous campaign against the exhibition.
The skeleton will go on display first at the Houston Museum of Natural Science.
Ethiopian officials said New York, Denver and Chicago were among the other US tour stops.