Temporal changes in Arikara humeral and femoral cross-sectional geometry associated with horticultural intensification

Humeral and femoral cross-sectional properties from three archaeological variants of the Arikara, an American Great Plains Indian tribe, were analyzed for temporal (16th to 19th centuries) changes in long bone architecture, asymmetry, and sexual dimorphism associated with intensification of horticulture during the late protohistoric and early historic periods. There were a number of significant changes in long bone, especially femoral, cross-sectional morphology and asymmetry among females through time that probably reflect increases in the workload necessary to produce surplus crops. Changes in long bone architecture among males are restricted to the humerus and may reflect a greater reliance on firearms. The pattern of sexual dimorphism also changes through time among the Arikara due to a combination of environmental (nutrition and disease) and mechanical factors.     

The Retromolar Space: A Morphological Curiosity Observed Amongst the Protohistoric Arikara and Mandan

The retromolar space (RMS), defined in palaeoanthropology as a space posterior to the third molar, between the distal edge of the tooth and the anterior margin of the ascending ramus when the mandible is held in lateral view, has been described as an autapomorphic trait unique to Neanderthals despite its presence in anatomically modern humans. This study examined RMS prevalence in a sample of protohistoric Arikara and Mandan Amerindians to determine what craniofacial morphology is correlated with the RMS. It was hypothesised that the feature would be present in the Amerindians studied and associated with a long cranial length, a large nasal height, midfacial prognathism, a broad mandible, and dental wear. The results indicated that RMSs were present in the Arikara and Mandan and significantly correlated with cranial length, cranial breadth, nasal height, bizygomatic breadth, basion‐nasion length, basion‐nasiospinale, mandible length, gonial angle, bigonial breadth, and dental wear. Thus, RMSs are associated with a dolichocephalic skull, wide cranial and facial breadth, a prognathic face, large nose and a corresponding wide and long mandible with a reduced gonial angle. This suggests that the RMS is the result of these features merging together in the craniofacial complex and should not be considered a Neanderthal autapomorphy. Copyright © 2015 John Wiley & Sons, Ltd.     

Occlusal molar microwear and the diets of the Ipiutak and Tigara populations (Point Hope) with comparisons to the Aleut and Arikara

Archaeological excavations at Point Hope, Alaska uncovered skeletal remains of two populations: the Ipiutak (100 B.C.–500 A.D.) and Tigara (1200–1700 A.D.). Archaeological evidence indicates that, although both groups relied on animal (largely marine) resources for their subsistence, the Ipiutak were mainly caribou hunters, whereas the Tigara were primarily whale hunters. To date, no study has attempted to ascertain whether the inferred dietary differences of these two groups could be substantiated using a more direct technique, e.g. microwear or stable isotope analysis. In this study, the occlusal molar microwear fabrics of the Ipiutak and Tigara were analyzed. Comparative data for two other modern human groups, the Aleut and Arikara, were also examined. Significant differences in microwear signatures were detected among the groups considered. The results of this study show that the Tigara have significantly more microwear features, more pits and narrower scratches compared to the Ipiutak. These results are concordant with interpretations that the two Point Hope populations had significantly different dietary habits. Differences in microwear signatures between the Aleut and the two Point Hope populations were also detected. Compared to the two Point Hope populations, the Aleut has significantly fewer features and wider scratches. The Aleut microwear signature further differs from that of the Tigara in having significantly lower pitting incidence. The microwear pattern of the Arikara, who had a mixed diet, differed from that of the mainly meat-eating Aleut and Point Hope peoples in that the Arikara has significantly fewer features, lower pitting incidence and narrower scratches.