A picture of a 4,000-year-old "fidget spinner" that went viral earlier this week isn't actually what it looks like, according to a museum curator.

A photo of the artefact was posted to Twitter, which showed the clay item labelled as a "spinning toy with animal heads" dating back to 2000 - 1500 BC.

It was shared thousands of times, with many people describing it as an ancient version of a fidget spinner, the popular craze of early 2017.

But Jean Evans, curator of the Oriental Institute Museum in Chicago – where the piece is kept – has claimed that the piece isn't actually a fidget spinner created by the Mesopotamians, but the head of a mace-like weapon used in combat by soldiers.

The item was discovered near a temple in Iraq in the 1930s. This explains the mace theory, as they were seen as "weapons of the gods", Evans told The Verge.

Evans also explained why the museum believed it was a toy. "All I can say is that our ideas change over time," Evans said.

"When the 'spinning toy' was first published in 1932, the excavators recognised that the object was unique, and they speculated it might be rotated and used in 'astrological divination.'"

Toys dating back to ancient Mesopotamia have been uncovered however, Evans added, including rattles and whistles.