Previously it had been thought that weaving had been invented by settled farmers just 5,000 to 10,000 years ago.

The new information means features on figurines thought to be prehistoric hairstyles are actually the first known hats.

The clues came from 90 fragments of clay found in the Czech Republic, at well-known sites including Dolni Vestonice and Tavlov. They reveal the impressions of interlaced fibres.

Looming large

Olga Soffer of the University of Illinois and her colleagues say the impressions indicate a huge variety of fine weaving techniques, including open and closed twines and plain weave, basketry and nets.

According to Dr Soffer, twining can be done by hand but plain weave requires a loom - impressive technology at such an early date.

Some of the impressions may have been created accidentally, by sitting on a freshly-laid clay floor, for example, or by leaning against a wet wattle-and-daub wall. Wet clay may also have been carried in cloth bags.

"Other impressions may have been caused by deliberate action, such as lining a basket with clay to make it airtight," said Dr Soffer, whose work is reported in the magazine British Archaeology.

Hat or hair

After discovering the impressions on the clay fragments, the archaeologists re-examined a number of "Venus" figurines found in Europe, which date from the same time.

Many appeared to be wearing clothing including basket hats and caps, sashes and belts. Previously the hats had been interpreted as elaborate hairstyles.

"These figurines have been studied for decades but no-one has paid any attention before to the clothing," said Dr Soffer, who before becoming an anthropologist worked in fashion promotion in New York for 10 years.

Image of the Willendorf Venus courtesy of Austrian AEIOU project.