Morphological integration of the hominoid postcranium

Area of Science:

• Primate Paleontology
• Comparative Anatomy
• Evolutionary Biology

Background:

• Previous studies suggest distinct postcranial integration magnitudes in hominoids versus other primates.
• Understanding skeletal integration is crucial for evolutionary and developmental studies.

Purpose of the Study:

• To test if hominoid postcranial integration differs from cercopithecoids.
• To investigate if girdle elements exhibit lower integration across primate taxa.

Main Methods:

• Estimated integration magnitudes of eight postcranial bones using 3D surface scans from six primate species.
• Quantified integration using the coefficient of variation from interlandmark distances.
• Employed resampling and Mann-Whitney U tests for statistical comparison.

Main Results:

• Hominoid integration patterns were generally distinct, with most hominoids showing lower integration than cercopithecoids, except for Gorilla.
• Homo, Gorilla, and Pan displayed higher limb element integration than Hylobates and cercopithecoids.
• Girdle elements (scapula, os coxa) were consistently the least integrated, while limb elements (femur, radius) were most integrated.

Conclusions:

• Results support distinct patterns of postcranial integration in hominoids.
• Skeletal element geometric complexity influences integration magnitudes.
• Lower integration in girdle elements may reflect functional or developmental constraints.