A CT scan of an ancient Egyptian child's mummified body on display at a Pittsburgh museum has revealed a spearlike object within the upper spine and skull, but scientists say they do not know whether that is what killed the child. "They don't know if that was the cause of death or if the embalmers did that to keep the head steady in the sarcophagus," said Ellen James, spokeswoman for the Carnegie Museum of Natural History. The scan performed Wednesday at a Pittsburgh hospital also revealed that the child, who lived more than 2,000 years ago, was likely between 3 and 5 years old, younger than previously thought. X-rays done in 1986 had led scientists to believe that the child was about 8 years old. The earlier scan also showed that the child had an unusually large head, and James said researchers still do not know what caused the abnormality. Scientists also could not confirm the sex of the child.