The squamous part of occipital bone consists of two parts, supraoccipital and interparietal. The interparietal portion ossifies intramembranously and in rare cases may be separated from the supraoccipital part by a suture. It is then called as the interparietal or Inca bone. The occurrence of Inca variable is rare in humans. The authors here report a case of true interparietal or Inca bone in adult human skull. Knowledge of Inca ossicles in human skulls may be useful to neurosurgeons orthopedic surgeons, anthropologists, radiologists and forensic experts.
