External occipital protuberance

Near the line where it unites to the interparietal bone, the squamous part of the occipital bone shows the transversal prominence of the external occipital protuberance (protuberantia occipitalis externa).

In species like Dogs or Horses, where the occipital reflexes on the dorsal surface of the head, this protuberance occupies the upmost point of the cranium and marks the dorsal elbow of the bone, or 'nuchal elbow', by opposition to the 'basilar elbow' that corresponds to the condyles.

In species where the occipital bone stays confined to the nuchal surface of the head, (Bulls), it is reported  more or less lower on this face, and is much less prominent.