Superior Orbital Fissure Configuration

The superior orbital fissures separate the greater wings of the sphenoid bone, which are located just inferior to them (Aiello & Dean, 1990). This feature is of likely developmental importance because it is associated with a complex interplay of numerous bones within the region of the orbit-sphenoid. For example, many other separate bones help define the orbit, including the maxilla, ethmoid, lacrimal, frontal, and the zygomatic, which will all to varying degrees be affected by differing amounts of bone remodelling and displacement. Thus, their development adds substantially to the development of this region (Enlow & Hans, 1996). The character states and hominin allocations follows Strait and Grine (2001). The primitive condition is defined by the fissure representing a fossa, as observed in Pongo, Gorilla, Pan, Praeanthropus, Australopithecus, and H. habilis (= 0), while the same condition is "comma" shaped in P walkeri, P. boisei, and H. sapiens (= 1). This feature could not be observed in other hominins due to problems of preservation.

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