supra-occipital

Above the foramen magnum the median supra-occipital bone completes what is called the occipital arch.

Text Book of Biology, Part 1: Vertebrata 1906

I at first thought of taking the length of the skull by a craniometer, and seeing what portion of the total length to the posterior edge of the sacrum it would be, but I soon discarded the idea on account of the variation in the supra-occipital process.

Natural History of the Mammalia of India and Ceylon Robert Armitage Sterndale 1870

In the Labrador duck the premaxillaries are rather broader than in the wild duck; and in two skulls of this breed the vertical ridges on each side of the supra-occipital bone are very prominent.

The Variation of Animals and Plants Under Domestication, Vol. I. Charles Darwin 1845