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Updated: Aug 26, 2025
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Dissection, MicroCT Scanning and Morphometric Analyses of the Baculum
Published on: March 19, 2017
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Sexual dimorphism and biomechanical loading in occipital bone morphological variation
Kara C Hoover1, Geoffrey P Thomas2
1Department of Anthropology, University of Alaska, Fairbanks, Alaska, USA.
Summary
Biological sex influences occipital bone variation, but subsistence practices do not significantly alter these traits. Foramen magnum area shows sexual dimorphism, though sex estimation accuracy remains limited.
Area of Science:
- Biological anthropology
- Forensic anthropology
- Skeletal biology
Background:
- Occipital bone traits are used for biological sex and ancestry determination.
- Previous studies show variable success in using occipital traits for classification.
- Biomechanical stress from subsistence and labor divisions may impact occipital variation.
Purpose of the Study:
- To investigate the influence of biological sex and subsistence-related biomechanics on occipital bone variation.
- To assess if subsistence practices explain inconsistencies in sex and ancestry estimations.
- To analyze metric and nonmetric occipital traits in diverse skeletal collections.
Main Methods:
- Analysis of metric traits: foramen magnum length/breadth, external occipital protuberance depth, lambda-inion length, bicondylar breadth.
- Evaluation of nonmetric traits: general occipital form, nuchal crest presence, nuchal line count.
- Utilized original and published data from Native American, military, and contemporary skeletal collections.
Main Results:
- Foramen magnum area shows sexual dimorphism, unaffected by subsistence; sex estimation accuracy is 71%.
- All analyzed traits demonstrated sex-based variation.
- Bicondylar breadth and lambda-inion metrics showed subsistence-based variation.
Conclusions:
- Biological sex is a significant factor in occipital bone variation.
- Subsistence practices have a limited impact on the analyzed occipital traits.
- Further research with diverse skeletal samples and known occupations is needed to fully understand occipital variation.
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