Alexandra Kralick

University of Pennsylvania | UP · Department of Anthropology

Objectives: While dental development is important to life history investigations, data from wild known-aged great apes are scarce. We report on the first radiographic examination of dental development in wild Virunga mountain gorillas, using known-age skeletal samples recovered in Rwanda. Materials and methods: In 43 individuals (0.0-14.94 years...

Deeper or more 'severe' linear enamel hypoplasia (LEH) defects are hypothesized to reflect more severe stress during development, but it is not yet clear how depth is influenced by intrinsic enamel growth patterns. Recent work documented inter- and intraspecific differences in LEH defect depth in extant great apes, with mountain gorillas having sha...

Bimaturism is rare among primates and most pronounced in adult male orangutans, who are either flanged with secondary sexual characteristics or unflanged with arrested secondary sexual characteristic development. Yet, the effect of developmental arrest on the orangutan skeleton remains relatively unexplored. Initial work with collections from the S...

Osteoporosis is a significant cause of morbidity and mortality in contemporary populations. This common disease of aging results from a state of bone fragility that occurs with low bone mass and loss of bone quality. Osteoporosis is thought to have origins in childhood. During growth and development, there are rapid gains in bone dimensions, mass,...

Objectives: We compared an early life stress indicator, linear enamel hypoplasia (LEH), in the canine teeth of two male orangutan (Pongo spp.) morphs. Flanged males have large bi-discoid cheek pads and a laryngeal throat pouch, and they exhibit either the same or higher levels of the stress hormone cortisol throughout development compared with unf...

Orangutans are endangered primates that live in Asian forests. Each year, these forests are becoming more stressful to live in because of habitat destruction and deforestation. The stress of habitat change may affect some orangutans more than others. As male orangutans age, some of them grow big cheek pads on their faces, called flanges (flanged ma...

Manuscript submitted to Integrative and Comparative Biology titled "Body Size Variation among Adult Male Orangutans and its Implications for Sexual Dimorphism in Pongo spp." currently in review in the journal Integrative and Comparative Biology

Differences in habitat continuity and predators have been posited as explanations for higher rates of terrestrial locomotion in Bornean compared to Sumatran orangutans. However, it is unclear whether greater terrestriality in Bornean orangutans is due to recent environmental changes to their habitats. Orangutan skeletons collected a century ago may...

Extensive discourse exists on research ethics for living apes, but there has yet to be a forum for discussing the treatment of their remains from a reflexive perspective that integrates ethics, methodology, and theory construction. In this session, we will explore the tension between approaches that consider specimens only at the population or spec...

African apes are all primarily terrestrial knuckle-walkers but western lowland gorillas (Gorilla gorilla gorilla) climb more frequently than do eastern gorillas (Gorilla beringei), a consequence of ecological differences in their respective habitats. Although bonobos (Pan paniscus) have generally been assumed to be more arboreal than common chimpan...

Orangutans exhibit intrasex bimaturism, a trait rare among primates. Males exist in two morphs: flanged, with large bidiscoid cheek pads on their face and a laryngeal throat pouch, and unflanged, lacking secondary sexual characteristics and displaying “developmental arrest.” Flanged males in captivity are shown to have higher levels of testosterone...

During the Early Acheulean, large flakes, often > 10cm, were consistently produced. Controlled knapping experiments show the amount of force required to remove a flake is positively related to its size. We conducted controlled knapping experiments on cores of different raw materials (glass, basalt, flint, obsidian, banded ironstone, and andesite) t...

Adult male orangutans are polymorphic, with adult males as either flanged with secondary sexual characteristics or unflanged with arrested secondary sexual characteristic development. The factors that mediate the developmental arrest are poorly understood and the effect on bone and dental development remains unexplored. This study examined the rela...

Abstract: Gorillas inhabit a range of central African habitats that differ in altitude and forest ecology. While all gorillas are primarily terrestrial knuckle-walkers, western gorillas (Gorilla gorilla) eat fruits and climb more frequently than do eastern gorillas (Gorilla beringei), a consequence of their respective lowland and highland habitats....