The distinctive horns of the new Bos also broach some other interesting matters, said Olsen. For one thing, this was an animal that had to live out in open areas, just like early humans. It's very hard to imagine any animal with such long horns surviving in a forest, she said.
Then there is also a tantalizing resemblance between the newfound Bos and depictions of bulls in ancient petroglyphs found in western Saudi Arabia -- along the route once taken by humans out of Africa. The rock art shows exceptionally long-horned cattle being hunted by humans with bows, arrows and dogs, Olsen said. The petroglyphs are at least 5,000 years old, she said, but very hard to date exactly.
"(The new Bos species) look so much like the pictures in Saudi Arabia," said Olsen, "which people have thought were exaggerations."
The ancient pictures also include depictions of some of the other animals known to have left Africa by the same route: lions, cheetahs and hyena, she said.
The message from the new fossil echoes those being discovered about the prehistory of other domesticated animals, including horses, which Olsen has studied, in particular.