dorsum sellae dorsum sellae the dorsum sellae is part of the sphenoid bone in the skull. together with the basilar part of the occipital bone it forms the clivus. dorsum sellaesphenoid bone. upper surface. (dorsum sellae is labeled in the white portion in the center.)base of the skull. upper surface. (dorsum sellae is not labeled, but sphenoid bone is in yellow, and dorsum sellae would horizontally be at the exact center, and vertically at the level of the posterior clinoid process.)detailsidentifierslatindorsum sellae, dorsum sella turcicata98a02.1.05.010ta2594fma54718anatomical terms of bone in the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the middle clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellae, ending at its superior angles in two tubercles, the posterior clinoid processes, the size and form of which vary considerably in different individuals. additional images tentorium cerebelli from above. dorsum sellae