Dictionary.net

• A bone found in the skulls of the children of the Peruvian races. It lies in the situation of the upper angle of the occipital bone, where the parietal bones separate from each other; and is the analogue of the interparietal bone of ruminants and carnivora. - Tschudi.

1846 - Medical lexicon: a dictionary of medical science
By Robley Dunglison

• In the human fetus, the tabular portion of the occipital b., which sometimes persists through life as a distinct b.

1916 - Appleton's medical dictionary
By Smith Ely Jelliffe