“This is the first imagery of a dog with a leash,” said Michael Petraglia, an archaeologist from the Max Planck Institute for the Science of Human History, in Germany, and an author of the study, which appeared in the Journal of Anthropological Archaeology and was first reported by Science. He said that because of where the lines were on the dog and human’s anatomy, they most likely represented actual leashes and were not mere symbolic lines.

Dr. Petraglia added that the rock art most likely dated to the early Holocene period, which began around when the Paleolithic ice age closed. But he acknowledged that the team was unable to date it directly because the etchings left little indication for when they were carved. Instead the team correlated the rock art with nearby archaeological sites that they had dated.

The team also found that the dog images were carved beneath images of cattle, which they said indicated that the dog images came earlier. They said earlier evidence had suggested these particular ancient humans had domesticated dogs before they began keeping cattle. They added that the transition from being hunter-gatherers to herding most likely occurred between 6,800 B.C. and 6,200 B.C., which they used to hypothesize that the rock art featuring dogs appeared before humans began herding.

“We can now say about 9,000 years ago people already controlled their dogs and had them on leashes and used them for really complex hunting strategies,” said Maria Guagnin, an archaeologist from the Max Planck Institute for the Science of Human History and lead author. She worked in partnership with the Saudi Commission for Tourism and National Heritage.