Book contents
- Frontmatter
- Contents
- List of text-figures
- List of plates
- List of tables
- Introductory Note
- Foreword
- Editor's Note
- Acknowledgements
- I Introduction
- II Preservation and reconstruction of the cranium
- III The cranial vault
- IV The basis cranii externa
- V Certain critical angles and indices of the cranium
- VI The interior of the calvaria
- VII The thickness of the cranial bones
- VIII The endocranial cast of Zinjanthropus
- IX Metrical characters of the calvaria as a whole
- X The structure of the face
- XI The pneumatisation of the Zinjanthropus cranium
- XII The dental arcade and the palate
- XIII The pattern of dental attrition and occlusion, with comments on enamel hypoplasia
- XIV The size of individual teeth, absolute and relative
- XV The size of the dentition as a whole
- XVI The crown shape index of the teeth
- XVII The morphology of the teeth
- XVIII Summary of cranial and dental features of Zinjanthropus
- XIX The taxonomic status of Zinjanthropus and of the australopithecines in general
- XX The cultural and phylogenetic status of Australopithecus boisei and of the australopithecines in general
- References
- Index of persons
- Index of subjects
- Plate section
VI - The interior of the calvaria
Published online by Cambridge University Press: 05 November 2011
- Frontmatter
- Contents
- List of text-figures
- List of plates
- List of tables
- Introductory Note
- Foreword
- Editor's Note
- Acknowledgements
- I Introduction
- II Preservation and reconstruction of the cranium
- III The cranial vault
- IV The basis cranii externa
- V Certain critical angles and indices of the cranium
- VI The interior of the calvaria
- VII The thickness of the cranial bones
- VIII The endocranial cast of Zinjanthropus
- IX Metrical characters of the calvaria as a whole
- X The structure of the face
- XI The pneumatisation of the Zinjanthropus cranium
- XII The dental arcade and the palate
- XIII The pattern of dental attrition and occlusion, with comments on enamel hypoplasia
- XIV The size of individual teeth, absolute and relative
- XV The size of the dentition as a whole
- XVI The crown shape index of the teeth
- XVII The morphology of the teeth
- XVIII Summary of cranial and dental features of Zinjanthropus
- XIX The taxonomic status of Zinjanthropus and of the australopithecines in general
- XX The cultural and phylogenetic status of Australopithecus boisei and of the australopithecines in general
- References
- Index of persons
- Index of subjects
- Plate section
Summary
The endocranial surface of the frontal bone
Only a small part of the endocranial surface of the frontal bone is present. The angle between the squama and the floor of the anterior cranial fossa is difficult to determine, because only the rostral end of the floor is present; it seems, however, to be much nearer the angle in Homo erectus pekinensis (50°) than that of modern man (about a right angle–Weidenreich, 1943, p. 32). Laterally, the posterior turn or recurvation of the squama at the postorbital constriction is clear, giving an extremely narrow frontal region. From the mid-line, the chord to the line of recurvation is only 31·0 mm. The endocranial width between the left and right lines of recurvation is 59·4 mm.
There is a thin though strong frontal crest, as in Pekin Man and other hominines. In pongids, on the other hand, it is missing or, at most, is represented ‘by a low, insignificant ridge’ (Weidenreich, 1943, p. 32). The relationship of the frontal crest to the sulcus for the superior sagittal sinus is described in Section D of this chapter (p. 63). Weidenreich regarded the internal frontal crest as part of the sagittal reinforcing system of the cranial vault of Pekin Man; he drew attention to the fact that the frontal crest fades out just where the sagittal thickening (which he unfortunately designated ‘sagittal crest’) originates on the outer surface.
- Type
- Chapter
- Information
- Olduvai Gorge , pp. 53 - 71Publisher: Cambridge University PressPrint publication year: 1967