11182_doi_deposit
20220127080000
assa
nadiag@assaf.org.za
assa
South African Journal of Science
S. Afr. J. Sci
1996-7489
01272022
118
1/2
The use of Z-scores to facilitate morphometric comparisons between African Plio-Pleistocene hominin fossils: An example of method
J. Francis
Thackeray
Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
https://orcid.org/0000-0001-6884-382X
Ottmar
Kullmer
Department of Palaeoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt, Germany
https://orcid.org/0000-0002-5929-8070
South Africa and East Africa each have a rich palaeoanthropological heritage, but the taxonomy of fossil hominins from these regions is controversial. In this study, two morphometric methods related to the quantification of variability in morphology have been applied to pairwise comparisons of linear measurements of hominoid crania and mandibles. The log-transformed standard error of the m-coefficient (‘log sem’) is calculated from linear regressions. Like Procrustes Distances (PD), log sem statistics can serve to quantify variation in the shape of a cranium or mandible in the context of a constellation of landmarks. In this study, PD and log sem statistics are integrated and standardised using Z-scores, and applied probabilistically to Plio-Pleistocene hominins. As a test case, OH 7 and OH 24 as reference specimens of Homo habilis are compared to fossils representing other taxa. There is a wide spectrum of variation in Z-scores for specimens attributed to early Homo dated within the period between circa 1.8 Ma and 2 Ma. In terms of morphometric variation predating 1.8 Ma, Z-scores (Z<2) for Australopithecus afarensis, A. africanus and Homo habilis display a small range of variability. This study serves as a demonstration of a method whereby log sem and PD can be used together to facilitate an objective assessment of morphological variability, applicable in palaeontological contexts.
01272022
1
10.17159/sajs.2016/crossmark
sajs.co.za
false
2021-05-21
2021-10-21
2022-01-27
National Research Foundation
http://dx.doi.org/10.13039/501100001321
https://creativecommons.org/licenses/by/4.0/
10.17159/sajs.2022/11182
20220127080000
https://sajs.co.za/article/view/11182
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https://sajs.co.za/article/view/11182/17911
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https://sajs.co.za/article/view/11182/17911
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https://sajs.co.za/article/view/11182/17911
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https://sajs.co.za/article/view/11182/17911
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https://sajs.co.za/article/view/11182/17911
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https://sajs.co.za/article/view/11182/17911
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https://sajs.co.za/article/view/11182/17911