Hipsters wanting the ultimate retro look, take note: Two pairs of trousers from China may be the earliest yet found.
Their straight legs and wide crotches suggest that the invention of trousers was linked to the rise of horse riding.
Robes, tunics and loincloths were the clothing of choice throughout much of prehistory. Trousers are a more recent innovation.
Mayke Wagner at the German Archaeological Institute in Berlin and her colleagues studied two pairs of woollen trousers from a cemetery in Xinjiang, China. Carbon dating shows they are about 3,000 years old.
Before that time, local people wore skirts and cloaks - but then horse riding became popular.
"During normal movements, the inner parts of the legs, the crotch and the lower abdomen are not exposed to friction over an extended period of time," Wagner says.
"This only becomes an issue when straddling a horse daily."
Wagner made a reproduction pair and realised that the wide crotch piece hangs down in folds, similar to drop-crotch pants as worn by Justin Bieber.
When one of Wagner's colleagues wore them, "he had the clear impression that the trousers would be uncomfortable for long walking," Wagner says.
The wide crotch would protect the groin, making straddling a horse easy. The idea of their design being linked to horses is supported by the riding gear found in both graves.
"Trousers are a critical development in tailoring," says Abby Lillethun of Montclair State University in New Jersey. She says historians have long suspected a link with horse riding.
"The surprise in these trousers is the woven cross-stepped [crotch piece] that provides the expected functional aspects of crotch protection and full movement but also coverage of the inner thigh that is needed on horseback."
Despite their age, the trousers had exquisite detail woven into the wool.
"We tend to underestimate the efforts people spent on making garments several thousand years ago, because they are seldom preserved," says Wagner. "Clothes were all about style and appearance, not only function."
- Washinton Post