Ancient cave painters in Europe recorded, over thousands of years, the development of modern bison from the hybridization between wild aurochs and steppe bison

Modern European Wisent, or Bison, or Buffalo, as we call them here in North America.

Early fossil records have shown that two major forms of bovids (a family of hoofed mammals, including cattle, sheep and goats) were present in Europe: the aurochs (the ancestors of modern cattle) and the steppe bison. 

The University of Adelaide researchers used bones from 64 ancient bison to study the origins of the group.

"We were surprised to find that the DNA we were getting back from these bones didn't look entirely like the modern European bison, they looked quite different," lead researcher Prof Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide, told BBC News.

"We determined that the European bison, bizarrely enough, is a hybrid between an auroch - which is the ancestor of modern cattle - one of the world's most ferocious wild animals, and a steppe bison, which ranged all the way across the grasslands of Russia, into Alaska and all the way down to Mexico in the Americas."

The difference was clearly noted by early cave painters in Europe.

Bisons painted by ancient Europeans at the Pergouset cave (Ardeche, France) look more like the modern European bison.

Meanwhile, paintings in the Chauvet-Pont d’Arc cave (Ardeche, France) look more like the seven legged ;-) Steppe bison.

Radio carbon dating of the bones revealed that each of the bison had been dominant at different times, due to changes in the environment.

The scientists found the age of the cave paintings matched this flux.

The cave paintings came from sites across France and Spain, including Grotte de Lascaux in the Dordogne and Grotte Chauvet-Pont d'Arc in the Ardeche.

Paintings from more than 18,000 years ago show creatures with long horns and hefty forequarters, like the American bison, which is descended from the Steppe bison.

However, more recent paintings (about 12,000 to 17,000 years old) show animals with shorter horns and smaller humps, similar to modern European bison.

"It looks like the cave artists were actually spotting the difference and actually recording them in their art," said Prof Cooper.