modern variation and evolutionary change in the hominin eye orbit

2000). The basicranium provides a platform on which the brain can sit and from whichthe face can grow, and in one way or another connects the cranium with the rest of thebody. For example, this feature articulates with the mandible and vertebral column,provides a channel through which the neural and circulatory connections of the face,neck, and brain can pass, forms the roof of the nasopharynx, while housing andconnecting all of the sense organs in the brain (Kuroe, Rosas, Molleson, 2004;Lieberman, Ross, Ravosa, 2000).In humans, the cranial base appears as a cartilaginous platform called thechondrocranium at about 2 months of embryonic development. At seven weeks it isseparated by the mid-sphenoid synchondrosis into the prechordal (anterior) andpostchordal (posterior) portions, which grow relatively independently of each other,possibly as a result of their different embryonic origins and/or different spatial andfunctional roles (Lieberman, Ross, Ravosa, 2000).The center of the basicranium near the sphenoid body reaches adult size andshape earlier than the surrounding regions, while the anterior, middle, and posteriorcranial fossae grow slightly longer and more or less independently of each other (Bastir& Rosas, 2005; Lieberman, Pearson, Mowbray, 2000; Lieberman, Ross, Ravosa, 2000),with each involved in a complex series of growth events that mainly involvedisplacement and drift (Lieberman, Ross, Ravosa, 2000).Despite the relative independence among dimensions of the cranial base, its size,shape, and degree of flexion play an important role in neurocranial and facial growth(Enlow & Hans, 1996; Kohn et al. 1993; Lieberman, 1998; Lieberman, Ross, Ravosa,2000; Ross, 1995; Ross & Ravosa, 1993), and because the cranial base acts as a bridge7