Does posture at death reveal behavior patterns?

Abstract

Studies on functional morphology are common in the field of evolutionary anthropology. Many anthropologists observe and meticulously record the locomotor behavior of primates, categorize them, and seek to understand how their anatomical features either aid or constrain them in their movements. Correlations can be made between robust, funny-shaped, or non-existent skeletal features and the range of movement (ROM) capabilities of the animal. Using traditional methods of measuring cadaveric specimens in order to discern species-specific morphological features has been done for a long time, but no one has thought to look at cadaveric posture as a method of inferring behavior in strepsirrhine primates. This study utilized 3D digital models of articulated hands to measure hand angles as a proxy for hand posture, with the goal of determining if death posture covaries with bony morphology and locomotor behavior. We found that the hand angle measurement protocol developed for this study can reliably measure ROM and that there is statistically significant evidence of unequal variance between species attributed to species-specific differences in posture. Principle Components Analysis (PCA) conducted on carpal morphology indices yielded some strong, grouped correlations, suggesting that there are interspecific variances attributed to the length or robustness of certain carpal features. Not all species plotted where they were expected to based on their locomotor category, so we cannot prove there is a significant correlation between morphology and behavior. Nor were the trends strong enough to prove a correlation between hand posture and carpal form. However, it is still possible these methods can be refined and utilized to infer behavior in fossil primates in the future.