Keywords

Geometric Morphometrics; Sexual Dimorphism; Juvenile

Abstract

Sex estimation of unknown individuals is one of the primary goals of biological anthropologists. The adult skull is often used in sex estimation, due to its marked traits of sexual dimorphism. However, estimating skeletal sex from juvenile remains is controversial due to the uncertainty surrounding the presence of sexual dimorphism prior to sexual maturity. The aim of this study was to apply geometric morphometric shape analysis to non-adult skulls to explore patterns of sexual dimorphism during ontogeny and to identify the most dimorphic region(s) of the skull. Computed tomographic (CT) scans were acquired from the New Mexico Decedent Image Database comprising 101 male and 99 female skulls ranging in age between birth and 21 years. Three-dimensional coordinates (42 landmarks and 290 curve semilandmarks) were placed on surface models generated from the CT scan and four landmark configurations were evaluated: the anterior cranium, mandible, supraorbital margin and glabella, and mastoids. Generalized Procrustes superimposition, principal component analysis, and discriminant function analysis were applied to all four configurations independently. In line with previous studies, results demonstrated a low degree of sexual dimorphism and poor cross-validated classification accuracy in individuals less than 13 years of age, with the highest accuracy in the mandible and the anterior cranium. The shape similarities found between the sexes prior to 13 years of age prevent consideration of the craniofacial bones as a sex indicator in the early stages of development but support its use in adolescent individuals, especially when using multiple regions of the face.

Completion Date

2023

Semester

Fall

Committee Chair

Freidline, Sarah

Degree

Master of Arts (M.A.)

College

College of Sciences

Department

Anthropology

Degree Program

Anthropology

Format

application/pdf

Identifier

DP0028092

URL

https://purls.library.ucf.edu/go/DP0028092

Language

English

Release Date

December 2026

Length of Campus-only Access

3 years

Access Status

Masters Thesis (Campus-only Access)

Campus Location

Orlando (Main) Campus

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Restricted to the UCF community until December 2026; it will then be open access.

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