Researchers in Nevada have discovered petroglyphs (rock engravings) that could be as ancient as 14,800 years old.

The petroglyphs or rock engravings, which have been found along a dried-up river bed, were engraved into the limestone rock.

The precise age of the petroglyphs has yet to be determined, but the researchers believe that the age of these petroglyphs should be in the range of 10,000 years to 14,800 years.

Even at the predicted earliest age of 10,000 years, these petroglyphs would be the oldest in the entire North American continent.

Researcher Larry Benson, of the University of Colorado, said, "Whether they turn out to be as old as 14,800 years ago or as recent as 10,500 years ago, they are still the oldest petroglyphs that have been dated in North America."

Benson added that the rock drawings are attractive and are some of the best instances of native artwork on the continent.

Researchers are of the view that Native Americans would have created these rock engravings, but who actually created these drawings is also yet to be determined.

The petroglyphs represent a range of things like clouds, lightning and the Milky Way.