Geometric Morphometrics
Definition
A method that captures biological shape as a configuration of landmark coordinates, removes position/orientation/scale differences by Procrustes superimposition, and analyses the residual shape variation statistically. Applied to sub-adult sex estimation via dental or pelvic landmark configurations; current accuracy 65-80 per cent.
- Core method
- Landmark coordinate shape analysis
- Key step
- Procrustes superimposition
- Application
- Sub-adult sex estimation via dental/pelvic landmarks
- Reported accuracy
- 65-80 per cent
Common questions
What does Procrustes superimposition remove from the data?+
It removes differences in position, orientation, and scale between specimens so that only genuine shape variation remains for statistical comparison.
Why is this method especially useful for sub-adult remains?+
Standard adult sex estimation features have not yet developed in juveniles, so shape-based landmark analysis of developing dental or pelvic structures can detect subtler differences that traditional metric or visual methods miss.
Why is 65-80 per cent accuracy still considered useful?+
Sub-adult sex estimation is difficult with any method because sexual dimorphism has not fully developed, so accuracy meaningfully above chance still adds probative value when combined with other lines of evidence.
Related terms
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- Femoral Head Vertical Diameter
- The superoinferior diameter of the femoral head, the most reliable single postcranial sex estimation measurement. US cut-offs (Stewart 1979): below 43.5 mm...
- Humeral Head Vertical Diameter
- The superoinferior diameter of the humeral head. US cut-offs (France 1998): below 43 mm female, above 47 mm male. Second most commonly...
- Khanpetch 2012
- A South-East Asian long-bone sex estimation study by Khanpetch and colleagues providing population-specific discriminant functions and cut-offs for Thai and South-East Asian...
- Procrustes Superimposition
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- Scapular Glenoid Breadth
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- Stewart 1979 Cut-Offs
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- Sub-Adult Sex Problem
- The inability of classical morphological and metric osteological methods to determine sex in individuals below approximately 12-15 years of age, because skeletal...