A 540,000-year-old shell carved with a geometric design may be the oldest known human art, a new study has found.
LiveScience reported that the shell of a freshwater shellfish, which is decorated with a jagged line, is an indication that "Homo erectus, the ancestor of modern humans, may have been smarter than was previously thought."
"We as humans tend to be a bit species-centric — we think we are so great and they must have been a bit more stupid than us, but I'm not sure," the study's lead researcher, Josephine Joordens, of Leiden University in the Netherlands, told LiveScience. "We need to appreciate the capacities of our ancestors a bit more."
More than 150 shells found in Java, an Indonesian island, in the 1890s were studied as part of the research, LiveScience said. Along with the engraving, some of the shells were found to have marks that indicated they may have been used as tools. One, for instance, had a smooth edge, and it might have been used for scraping.
National Geographic reported that, before this find, the earliest known examples of art made by human ancestors were 70,000 to 100,000 years old. That work was done in South African caves by Homo sapiens.
Although the zig-zag markings on the decorated shell are difficult to see now, Joordens told LiveScience that the shell would have been dark when it was being used and the lines would have shown up white. Researchers tried to carve shells today and found it a difficult task.
"You had to use a lot of strength in your hands," Joordens said. "You had to be precise to make those angles. [But] if you engrave that dark surface and the white appears, that must have been quite striking for Homo erectus."
While it has long been known that Homo erectus used stone tools, Joordens told LiveScience this is the first time evidence was found indicating they may have used tools from other materials.
"This raises the big, hairy question of what is 'modern human behavior' all over again," paleoanthropologist Pat Shipman, of Pennsylvania State University, told National Geographic.