Date of Award
Richard L Jantz
This study examines the growth of the ilium in an American Indian Skeletal series. This study was done because of the lack of previous Study in this area using statistical interpretation of the changes. The samples consists of subadults from four Arikara cemeteries found in northern South Dakota; two of the samples are separate occupations of the same site. An unknown age and sex sample was used because of its availability and because of the unavailability of known subadult Skeletal samples.
Eight measurements were taken on each ilium and two non-metric traits recorded. Maximum femur lengths, gathered in a previous study, were then matched with their corresponding ilia. Femur length was used as an indication of biological age and used to hold age changes constant. Logrithmic transformation of the raw data was performed to eliminate non-linear trends in the femur length to iliac relationships.
Allometric regression coefficients were calculated indicating relative rates of growth for each of the eight variables. Regression and eigenvalues were generated and principal components calculated for the eight variables. Inter-site correlations were evaluated from the residual means of the principal components. Each site was found to be Significantly different from the other in growth rates. Principal component analysis is examined and no significant components found.
Two non-metric traits were examined, the raised or non-raised shape of the auricular surface and the presence or absence of a spinous process on the posterior aspect of the sciatic notch. It was thought in a previous study that the auricular surface trait indicated sex differences in subadults. Results from this study show no significant sexual differences in either non-metric trait but only an age relationship associated with the age of ilium. One point of interest is the significant correlation of the two non-metric traits, the non-raised trait associated with a spinous observation and visa versa.
From this study it is concluded that there are apparent but no Significant correlations in the morphological changes due to age. No sexual separation was found in either the metric or non-metric data although correlation between the two non-metric traits was discovered. The causes for non-significant results is discussed and possible Gorrections proposed. Even with only trends and no significant results, the findings in this study shed some light on the age changes found in subadult ilia.
Hunt, David R., "Age Changes in Shape and Morphology in Arikara Subadult Ilia. " Master's Thesis, University of Tennessee, 1983.