Model-based inferring of Neanderthal upper cervical spine motion

Area of Science:

• Paleoanthropology
• Functional Morphology
• Biomechanics

Background:

• Previous hypotheses suggested reduced neck mobility in Neanderthals based on morphology.
• Direct measurement of fossil kinematics is impossible.

Purpose of the Study:

• To illustrate the potential of Procrustes Motion Analysis (PMA) combined with predictive modeling for studying fossil functional morphology.
• To model and compare the upper cervical spine (UCS) flexion-extension kinematics of the La Ferrassie 1 Neanderthal and modern humans.

Main Methods:

• Utilized 3D virtual morphology of the La Ferrassie 1 Neanderthal and modern human specimens (occipital base, C1, C2).
• Applied PMA to analyze shape-motion relationships in modern humans to build a predictive model.
• Applied the predictive model to Neanderthal UCS morphology to infer potential motion trajectory.

Main Results:

• The inferred flexion-extension trajectory for La Ferrassie 1 was statistically comparable to the modern human sample.
• Challenged assumptions of reduced Neanderthal neck mobility based on model-based results.
• Demonstrated no significant difference in UCS flexion-extension between the Neanderthal specimen and modern humans.

Conclusions:

• Procrustes Motion Analysis (PMA) integrated with predictive modeling is a robust tool for paleoanthropological functional morphology.
• The study provides a new framework for investigating hominin kinematics using empirical data and predictive modeling.
• Neanderthal upper cervical spine (UCS) flexion-extension kinematics were predicted to be similar to modern humans.