Carved in stone: were the Arabs the first to tame the horse?
That is the question posed by ancient sculptures unearthed from the Saudi desert and which have the potential to overturn the theory that horses were first domesticated in Central Asia.
If not for the prescience of a sharp-eyed Saudi camel owner, the scientific world might never have had reason to reassess the established wisdom that horses were domesticated by the tribes of the Eurasian steppe.
Mutlaq ibn Gublan had arranged for a contractor with a digger to excavate a pond for his camels, but moments before the digging was about to start, he noticed an object that was clearly both man-made and ancient.
And important. Just how important might never have been known if not for his decision to pay the contractor and send him away without any excavation having taken place. Realising the value of what might be in the ground, he instructed the contractor to follow the same tracks out to the road.
The site proved to be a treasure trove of about 300 objects but it was that very first piece that Gublan saw that has excited the scientific community because the 135-kilogram fragment of a much larger sculpture seems to depict a horse with a primitive bridle.
That excitement was increased when the Saudi Commission for Tourism and Antiquities (SCTA) did carbon-dating tests on organic material found alongside it and provisionally dated the horse-like fragment to between 6590 and 7250BC.
That put it about 2,000 years earlier than the first proven example of horse domestication, which was in what is now Kazakhstan.
The Kazakh evidence is definitive, with an American researcher, Sandra Olson, finding horse-milk metabolites in shards of clay pots. The impossibility of milking a wild mare shows they must have been domesticated and the organic nature of the material allows for accurate dating.
Olson's finding is bolstered by other evidence, such as the dramatic increase in village sizes at about the same time and changes in the genetic variety of horse bloodlines dating from the same era, 5,500 years ago.
But those who favour the theory that horses were domesticated independently and earlier in what were then the lush and fertile valleys of south-west Saudi Arabia can also point to corroboration.
Arabia was also one of the earliest civilisations to domesticate the dog and one of the 300 artefacts found in Al Magar civilisation, as Gublan's find has been titled, was a sculpture of a Saluki.
It was amid a menagerie of animal artefacts at the site: ostriches, sheep, goats, fish, a cow-like creature and, of course, the horse. Or at least a horse-like creature that researchers identified as an equid from the overall genus covering horses, asses, zebras or some hybrid of them.
Other finds showed a complex civilisation had existed at Al Magar, which translates as "gathering place" or "headquarters".
Also interred at the site were mortars and pestles, grain grinders, weights used for weaving, stone tools suitable for leather processing, arrowheads, stone blades, a soapstone pot ornamented with decorative motifs and an elaborately detailed stone knife in the shape of the traditional Arabian khanjar.
Ali Al Ghabban, the head of antiquities at SCTA, says the collection has already prompted a reassessment of development in Arabia during the neolithic, or new stone age, era.
He says the 300 artefacts demonstrate "a sophisticated society possessing a high level of art and craftsmanship that we have not previously seen".
For the finder, Gublan, he was quoted as saying it reinforces both his decision to stop the excavation and his pride in Saudi culture.
"I am happy that in the footsteps of my grandfather and his long line of ancestors I have found something from the heart of Arabia that goes deep into our history and helps connect us with the past," he says.
That sentiment was reflected in wider Saudi society, which was taking pride in its archaeological heritage and particularly in the suggestion that the region's eponymous breed of horse was also domesticated millennia before anywhere else.
The evidence from the 86-centimetre-long fragment spotted by Gublan is tantalisingly inconclusive.
The carving features a rounded head, arched neck, muzzle, nostrils, shoulder, withers and overall proportions that are clearly horse-like. The contention about domestication comes from two distinctive features, one of which suggests some kind of strap going from the shoulder to the forefoot and the other involving delicate incising around the muzzle.
The proof from the find goes no higher than that, being just carvings indicative of a kind of primitive bridle.
One expert on the subject of horse domestication, David Anthony, says he will go no further than suggesting that the sculpture at Al Magar "might be" from the horse genus.
Advances in genetic testing have allowed researchers to date the transition when early humans went from hunting wild horses for food to ensnaring and taming them.
It coincided with the rise of Equus ferus caballus, the domesticated subspecies of the wild Equus ferus, and it revolutionised the ability of people to connect over long distances and improved their ability to carry loads or wage war.
Anthony said although southern Mesopotamia featured the ass and the onager as the equid species, the earliest known Equus ferus caballus in Arabia is about 1800BC.
To prove the synopsis of domestication would require Equus ferus caballus bones to be found in effectively undisturbed geological strata that can be accurately carbon dated.
The SCTA sought the kind of definitive proof that would prove their case, inviting archeologists to Al Magar, where more artefacts - including another stone, horse-like sculpture - were unearthed.
The era 9,000 years ago is about the time when that part of Arabia was going through the start of a 5,000-year epoch of reliable rainfall which allowed a lush vegetation unimaginable today.
It was also the time that people in the region went from being hunter-gatherers to farmers, including the domestication of animals.
The commission took Olson, the discoverer of the Kazakh horse-milk remnants, to Saudi Arabia to assess rock art throughout the Kingdom to see if she could verify neolithic horse domestication.
More than 1,000 rock carvings have been found that depict equids being hunted, ridden or as draft animals.
While there are theories that some depictions of equine domestication date back to the neolithic era, the difficulty of accurately dating petroglyphs prevents a definitive answer.
Another diagnostic tool has been the burgeoning discipline of mitochondrial DNA analysis, where the relatively high diversity of maternal blood lines suggests that the domestication of horses occurred separately and independently up to 10,000 years ago and in several locations - but in Eurasia and possibly western Europe rather than in Arabia.
The hunt for the definitive proof of Arabian horse domestication goes on but most of the indicators - the relatively lush climate, the transition to agrarian life and the domestication of species such as dogs - are all consistent with it occurring.