Pretoria - A rare engraved skull has been stolen from a Ripley's Believe It or Not display in The Grove Mall in Pretoria, the mall's management said.It said the trophy skull was a rare example of the prized possessions once worn as necklaces by the Dyak headhunters in Borneo.The mall noticed it had gone missing on August 15."As one of the preferred malls in Pretoria, we are a little disappointed that someone [from]... the public removed the Dyak engraved skull, but of course we trust that this person will take special care of it," the mall's marketing manager Pierre Botha said."No stone was left unturned in our quest to keep all the artefacts safe, while not compromising the public’s enjoyment, so as to ensure that we return the display items safely to Ripley’s entertainment.”Kristi Maree, the managing director of Word 4 Word Marketing, Ripley’s Entertainment licence holder in South Africa said: “We trust that the public will help us recover the Dyak engraved skull, as we want to provide a display of the entire collection to the public for the remainder of the Ripley’s Believe It or Not! South African tour."The mall said it was offering a reward to any member of the public that had information leading to the recovery of the skull.People with information must call Botha on 012 807 0963.The Ripley’s collection, which includes more than 140 artefacts would be on display at The Grove Mall until Sunday.Thereafter, it would move to the Highveld Mall in Emalahleni from August 28 to September 20.