Several years ago, there was a jovial debate why Chris Messina, a former Google designer who proposed Twitter use the hashtag to sort topics, did not patent the idea and make millions off it – it turns out he might have been about 73,000 years too late.
The earliest known drawing made by a human has been found in a South African cave and it looks very similar to a hashtag, the grouping and search feature made popular by the Jack Dorsey-led Twitter.
The drawing is basically six red lines crossed by three other slightly curved lines. It appears on a tiny flake of mineral crust measuring only about 1.5 inches (39 millimeters) long and about half an inch (15 millimeters) tall. It's evidently part of a larger drawing because lines reaching the edge are cut off abruptly there, researchers said.
"Before this discovery, Palaeolithic archaeologists have for a long time been convinced that unambiguous symbols first appeared when Homo sapiens entered Europe, about 40 000 years ago, and later replaced local Neanderthals," said University of Bergen professor Christopher Henshilwood in a statement.
Henshilwood continued: "Recent archaeological discoveries in Africa, Europe and Asia, in which members of our team have often participated, support a much earlier emergence for the production and use of symbols."
The 73,000 year-old drawing was found in the Blombos Cave, approximately 190 miles east of Cape Town, researchers said. It is roughly 30,000 years older than any other drawing presently known to humanity, the researchers said.
The findings have been published in the scientific journal Nature.
While it is not the earliest deliberate design (some abstract engravings are significantly older), it does highlight that early humans were able to produce designs on various surfaces with different techniques. It was created with a sharpened flake of ochre, a pigment widely used in the ancient world, Henshilwood told the Associated Press.
"This demonstrates that early Homo sapiens in the southern Cape used different techniques to produce similar signs on different media," Henshilwood added in the statement. "This observation supports the hypothesis that these signs were symbolic in nature and represented an inherent aspect of the behaviorally modern world of these African Homo sapiens, the ancestors of all of us today."
Similar patterns are engraved in other artifacts from the cave, and the hashtag design was produced widely over the past 100,000 years in rock art and paintings, Henshilwood said. So the newly found sketch is probably not just a collection of random scratchings.
"It almost certainly had some meaning to the maker, and probably formed a part of the common symbolic system understood by other people in this group," he said.
The Associated Press contributed to this report. Follow Chris Ciaccia on Twitter @Chris_Ciaccia