Saudi officials say archaeologists have begun excavating a site that suggests horses were domesticated 9,000 years ago in the Arabian Peninsula.
The vice-president of the Saudi Commission for Tourism and Antiquities said the discovery at al-Maqar challenged the theory it first took place 5,500 years ago in Central Asia.
Ali al-Ghabban said it also changed what was known about the evolution of culture in the late Neolithic period.
A number of artefacts were also found.
They included arrowheads, scrapers, grain grinders, tools for spinning and weaving, and other tools that showed the inhabitants were skilled at handicrafts.
Mr Ghabban said carbon-14 tests on the artefacts, as well as DNA tests on human remains also found there, dated them to about 7,000 BC.
"This discovery will change our knowledge concerning the domestication of horses and the evolution of culture in the late Neolithic period," he told a news conference in Jeddah, according to the Reuters news agency.
"The al-Maqar civilisation is a very advanced civilisation of the Neolithic period. This site shows us clearly, the roots of the domestication of horses 9,000 years ago," he added.
Although humans came into contact with horses about 50,000 years ago, they were originally herded for meat, skins, and possibly for milk.
The first undisputed evidence for their domestication dates back to 2,000 BC, when horses were buried with chariots. By 1,000 BC, domestication had spread through Europe, Asia and North Africa.
However, researchers have found evidence suggesting that the animals were used by the Botai culture in northern Kazakhstan 5,500 years ago.