Reconstructing the Diet of an Extinct Hominin Taxon: The Role of Extant Primate Models

Abstract

Modern humans represent the only surviving species of an otherwise extinct clade of primates, the hominins. As the closest living relatives to extinct hominins, extant primates are an important source of comparative information for the reconstruction of the diets of extinct hominins. Methods such as comparative and functional morphology, finite element analysis, dental wear, dental topographic analysis, and stable isotope biogeochemistry must be validated and tested within extant populations before they can be applied to extinct taxa. Here we review how these methods have and might be used to reconstruct the diet of a particular extinct hominin, Paranthropus boisei, which has no extant analogue for its highly derived masticatory morphology. Our review emphasizes the potential and limitations of using extant primates as models for the reconstruction of extinct hominin diets. We encourage paleoanthropologists and those who study the feeding behaviors of extant primates to work together to investigate and validate methods for interpreting the diets of all extinct primates, including hominins.

Stable isotope-based diet reconstructions of Turkana Basin hominins

“…Some of the methods focus on the functional morphology of the masticatory system, others focus on tooth wear (both macroscopic and microscopic), and yet others focus on the physicochemical signatures that an animal's diet leaves within its hard tissues (1,2). Chemical methods include the use of strontium/calcium and barium/calcium ratios (3,4), but this study focuses on the analysis of stable isotopes of carbon (5)(6)(7)(8)(9).…”

Gelada feeding ecology in an intact ecosystem at Guassa, Ethiopia: Variability over time and implications for theropith and hominin dietary evolution

“…Wood and Schroer (2012) recently argued that because most extant primates eat varied diets, extinct primates, including P. boisei, should have been no different. However, neither the specific plant parts nor the species identities of dietary items can be inferred at present from stable isotope analysis, making it impossible to determine the dietary breadth of the putatively graminoid-eating extinct primates, T. oswaldi and P. boisei (Sponheimer et al, 2007;Cerling et al, 2011Cerling et al, , 2013.…”

“…Some have suggested that P. boisei relied mostly on sedge corms year-round (Dominy, 2012;Macho, 2014), while others envision a more varied (gelada-like) diet of above-and belowground grass and sedge items, possibly coupled with opportunistic consumption of invertebrates, bird eggs, and small reptiles and mammals (Cerling et al, 2011;Grine et al, 2012;Wood and Schroer, 2012). Unlike T. gelada and T. oswaldi which both possessed specialized hands for digging (Jolly, 1970;Dunbar, 1983), P. boisei may have required tools to access underground food items to have consumed them in large quantities (Sponheimer et al, 2013b).…”

Dietary variation and food hardness in sooty mangabeys (Cercocebus atys): Implications for fallback foods and dental adaptation

“…We are occasionally reminded (e.g., Wood and Schroer, 2012) that inferences about the fossil record must be validated using extant primate models and, in a number of instances, the analogy of thick-enameled grey-cheeked mangabeys consuming hard objects only during selectively critical fallback periods has served that purpose (Scott et al, 2005;Sponheimer, 2013;Ungar and Sponheimer, 2011;Wood and Schroer, 2012). But just as there are multiple mangabeys, so too are there multiple analogies.…”