Determining Sex of the Posterior Ilium from the Robert J. Terry and William M. Bass Collections : DETERMINING SEX OF THE POSTERIOR ILIUM

A new visual method for the determination of sex using the human hip bone (os coxae) is proposed, based on a revision of several previous approaches which scored isolated characters of this bone. The efficacy of the methodology is tested on a sample of 402 adults of known sex and age of French and Portuguese origins. With the simultaneous use of five characters of the hip bone, it is possible to provide a correct sexual diagnosis in 95% of all cases, with an error of 2% and an inability to identify sex in only 3%. The advantage of this new method is a reduction in observer subjectivity, since the evaluation procedure cannot involve any anticipation of the result. In addition, this method of sex determination increases the probability of a correct diagnosis with isolated fragments of the hip bone, provided that a combination of elements of one character is found to be typically male or female. Copyright 2002 Wiley-Liss, Inc.

Robert J. Terry began collecting human skeletal remains in the area of St. Louis, Missouri for research and educational purposes in 1898. He continued collecting skeletal specimens in the Anatomy Department at Washington University until his retirement in 1941. Mildred Trotter succeeded Terry as anatomy professor and continued his collecting, and strove to balance the demographic distribution of the collection. In 1967, after her retirement, the collection was moved to the Smithsonian Institution's National Museum of Natural History. As with several other well-documented collections, the Terry Collection is widely used for a diverse range of anthropological and medical research. Despite its extensive use, there has been limited discussion of the collection's history and incomplete description of holdings and associated materials of this collection. In this paper, the historical background of the collection and the collection process is described; the demographic composition of the collection, and a description of the documentary and supporting data are presented; and the quality and of these data are assessed. The Terry Collection consists of 1,728 individuals. Age at death ranges from 14-102 years, with the majority of the individuals ranging from 20-80 years. Year of birth ranges from 1828-1943; the mean year of birth for males is 1880, and for females it is 1884. The mean age at death for males is 53 years, and for females it is 58 years. Terry's strict protocols for the processing of cadavers and the recording of documentary data make the Terry Collection a valuable resource for anthropological and medical research.

This study assesses the accuracy and reliability of 17 individual morphological traits of the pelvis frequently used to determine the sex of human skeletal remains. A sample of 49 right and left adult hip bones and sacra of documented individuals were available from an historic church cemetery dating from the 19th century. A hypothetical ranking of the accuracy of traits was drawn from the literature. Next, individual traits were evaluated for precision and accuracy of observations, and combinations of two and three traits were evaluated for their collective effectiveness as sex indicators. The effect of age on the accuracy of traits for sex determination was also examined. Precision of traits was generally good. Several combinations of three criteria produced higher levels of accuracy than the trait list as a whole. A total of six traits was judged to be most effective as sex discriminators because of low intraobserver error levels and better than 83% accuracy rats. There was no indication of an age effect on the precision or accuracy of these traits although sample sizes are small.