Nature 381, 224–226 (1996)

One of the important morphometric variables assessed in the comparisons between the bony labyrinths of Neanderthals and modern humans is the sagittal labyrinthine index. This index expresses what percentage of the posterior semicircular canal is situated inferiorly to the plane of the lateral semicircular canal. Its formula, as given in the legend to Fig. 2 of the above Letter, is incorrect and should be i/(s + i) × 100.