New Method for Sex Prediction Using the Human Non‐Adult Auricular Surface of the Ilium in the Collection of Identified Skeletons of the University of Coimbra

Abstract

Sex estimation in non-adult skeletons is crucial in bioarchaeology and forensic anthropology. It was not extensively considered in the past, mainly because it was stated that the dimorphic osteological features were difficult to identify before adulthood. Over the past few years, this statement was disproved, and the study of numerous dimorphic non-adult skeletal traits was approached. This paper presents a new methodology that evaluates the auricular surface of the non-adult ilia. Several morphological and continuous variables were recorded for 34 individuals (21 females and 13 males) aged between 7 and 18 from the Coimbra Identified Skeletons Collection (University of Coimbra, Portugal).The results show low intra and inter-observer errors for all the variables, which renders the methodology replicable. Two ratios related to the shape of the anterior area of the auricular surface offer the most dimorphic data (proportions of cases correctly assigned: 0.82 and 0.88; sexual allocation probabilities: 0.85 for both variables). A discriminant function and a logistic regression were developed, which correctly classified the 82.35 and the 88.23% of the individuals, respectively. Moreover, two qualitative variables, referred to as the overall morphology and the apex morphology, also show statistically significant differences between males and females (proportions of correct assignation: 0.82 and 0.76; sexual allocation probabilities: 0.79 and 0.76).These variables can be incorporated in a multifactorial approach together with other indicators already available in the specialised literature in order to help improve the accuracy of the results obtained. This methodological procedure has to be applied with other identified samples, including younger individuals, so as to test whether the trends presented in this context are maintained and are useful in populations from a different geographical provenience.

Osteological evidence of short stature and parieto‐squamosal arch craniosynostosis in a non‐adult male from the 13th century Leiria, Portugal

“…Age at death was estimated based on dental eruption and development (AlQahtani, Hector, & Liversidge, ; Liversidge & Molleson, ), dental wear (Smith, ), and postcranial maturity (Scheuer & Black, ; Cardoso, , b). Because the pelvic bones were almost completely fused, sex estimation was done based on pelvic morphology (Bruzek, ; Luna, Aranda, & Santos, ). The mandible was also used (Ferembach, Schwidezky, & Stloukal, ).…”

A new multivariate method for determining sex of immature human remains using the maxillary first molar

“…Morphological methods have been criticized for high rates of inter‐observer error (Cardoso & Saunders, ; Luna, Aranda, & Santos, ; Sutter, 2008). Consequently, efforts have been made to develop metric techniques (Decker, Davy‐Jow, Ford, & Hilbelink, ; Krüger, L'abbe, & Stull, ; López‐Costas, Rissech, Trancho, & Turbón, ; Luna et al, ; Stull, L'Abbé, & Ousley, ; Wilson, Cardoso, & Humphrey, ; Wilson, MacLeod, & Humphrey, ). Even though reportedly more repeatable, metric methods require a good standard of skeletal preservation, which cannot be guaranteed, especially when dealing with the fragile remains of immature individuals.…”

“…Nonetheless, attempts to assign skeletal sex to immatures most frequently utilize the same skeletal traits known to be accurate for determining the sex of adults, including multiple features of the pelvis (Olivares & Aguilera, ; Rissech & Malgosa, ; Schutkowski, ; Sutter, ; Vlak, Roksandic, & Schillaci, ) and skull (Galdames, Matamala, & Smith, ; Loth & Henneberg, ; Molleson, Cruse, & Mays, ; Schutkowski, ). Morphological methods have been criticized for high rates of inter‐observer error (Cardoso & Saunders, ; Luna, Aranda, & Santos, ; Sutter, 2008). Consequently, efforts have been made to develop metric techniques (Decker, Davy‐Jow, Ford, & Hilbelink, ; Krüger, L'abbe, & Stull, ; López‐Costas, Rissech, Trancho, & Turbón, ; Luna et al, ; Stull, L'Abbé, & Ousley, ; Wilson, Cardoso, & Humphrey, ; Wilson, MacLeod, & Humphrey, ).…”

A Test of Sex Estimation in Subadults Using the Elevation of the Auricular Surface from Four Samples of Known Age and Sex

“…While it is posited that age plays a role in the expression of the auricular surface elevation , consequent to the widening of the female pelvis in puberty , the feature's expression has been assumed to present consistently across populations. However, adult studies have concluded that this trait may vary considerably between groups , and, more recently, researchers using the auricular surface for morphometric studies have cautioned that subadult pelvic traits may also be population specific. Regardless, sample variation has not been assessed for the auricular surface elevation in either adult or subadult samples.…”

“…For more than 100 years, researchers have noted dimorphism in the subadult pelvis (1)(2)(3) in several of the metric and nonmetric traits found useful for adult sex estimation. More recent attempts to quantify and produce sex estimation methods based on these traits have met with limited success (4)(5)(6)(7)(8)(9)(10). Currently, no reliable method of analysis has been developed to capture subadult sex differences, although auricular surface elevation on the ilium, a dimorphic nonmetric trait in adults, has shown promise (5,7,8).…”