A Dissertation Submitted to the Faculty of Science University
of the Witwatersrand, Johannesburg for the Degree of Master
of Science
January, 1990 / This is a study of the morphological and functional aspects
of A. africanus thoracic and lumbar vertebrae in comparison
with those of modern human and anthropoid ape vertebrae. The
purpose is to determine if any derived features in the
morphology of hominids, as distinct from primitive features
shared with non-hominids, were present and if so to what
stage of attainment of full erectness such features point.
The major results of this study are as follows: (i) There is
a difference in the configuration of the lumbar articular
facets between pongids, on the one hand, and modern human and
A. africanus, on the other hand. This difference suggests
that similar stresses operate in these regions in the two
hominid groups. (ii) Bony adaptation to a developed lumbar
lordosis is present in A. africanus. (iii) Major agreement
has been found in the relative dimensions of modern human and
A. africanus lumbar vertebrae, in contrast to those of pongid
vertebrae. This indicates probable correspondence in the
pattern of weight transmission to the pelvis in modern humans
and A. africanus. (iv) The decrease of inferior lumbar
vertebral body area starts at higher levels in sts 14 (an A.
africanus partial skeleton) than in modern man, suggesting a
longer curved lower lumbar region in A. africanus.
From these results it may be concluded that the trunk was
probably carried in a fully erect posture in A. africanus.
The bony adaptation thereto, however, may not have been fully
developed as in modern man. It is proposed that, in Sts 14,
the last two lumbar vertebrae were carried at an angle
relative to each other and to the sacrum, in contrast to the
abrupt change in direction between L5 and the sacrum in
modern man.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/20646 |
| Date | 18 July 2016 |
| Creators | Benade, Maria Magdalena |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf, application/pdf |
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