Michele Bleuze | California State University, Los Angeles (original) (raw)

Papers by Michele Bleuze

This case study evaluates a focal osteolytic lesion in the right sulcus sinus transversi of an is... more This case study evaluates a focal osteolytic lesion in the right sulcus sinus transversi of an isolated os occipitale. Materials: The os occipitale is from a juvenile from the Cueva de Sangre at the Classic Period (250− 900 CE) site of Dos Pilas, Guatemala Methods: The lesion was examined macroscopically, microscopically, and radiographically. Results: The oval lesion has a well-circumscribed margin, endocranial origin, and involves cortical destruction of the inner and outer tables. Subperiosteal bone reaction around the lesion is present on the ectocranial surface. Skeletal evidence of increased vascularity, diploë expansion, and perimortem fracture near the lesion are not observed. Conclusions: The lesion appears to reflect a response to the presence of an expansile process that has caused pressure erosion. The anatomical location of the lesion and the endocranial origin suggest a probable vascular anomaly, such as a vascular malformation. Significance: This case study represents one of the few bioarchaeological evaluations of probable vascular anomaly in a juvenile. As such, it expands our knowledge about vascular anomalies in the past and provides a comparative and core reference for guiding future paleopathological investigations on cranial osteolytic lesions. Limitations: The skeletal assemblage is commingled and fragmentary preventing the assessment of the distribution of lesions across the skeleton. Suggestions for future research: Further scrutiny of bioarchaeological collections is needed to better understand the distribution of vascular anomalies in the past.

Archaeological Discovery, 2023

In 1993, the Petexbatun Regional Cave Survey discovered a previously unknown composite material i... more In 1993, the Petexbatun Regional Cave Survey discovered a previously unknown composite material in the Cueva de los Quetzales, Petén, Guatemala. The composite material, consisting of layers of cotton fabric impregnated with ceramic slipping material, was analyzed by the Smithsonian Institution's Conservation Analytical Laboratory (now the Smithsonian Center for Materials Research and Education [SCMRE]). Recently, a micro-CT scan of one of the sherds has led the authors to question the established position that use of the composite technology was highly specialized and produced exclusively for the elite.

Totem: The University of Western Ontario Journal of Anthropology, 2007

Childhood in the Past, 2023

Differences between estimated dental and skeletal ages can provide a gauge of an individual’s gro... more Differences between estimated dental and skeletal ages can provide a gauge of an individual’s growth status, which more broadly reflects an individual’s health status. This case study provides a summary of the skeletal growth status in a dentally aged 2.0–2.5-year-old (Burial 519) victim of chronic physical abuse from the Kellis 2 cemetery (cal AD 100–450), Egypt. Absolute size of postcranial elements in Burial 519 is generally more similar to a dentally aged 1.5–1.9-year-old cohort than to an age-matched cohort. Growth deficits are least in the skull and greatest in the leg supporting previous studies demonstrating that these regions may be less sensitive and more sensitive, respectively, to environmental stressors. Within the postcranial skeleton, growth deficits are least in the clavicle which may have methodological implications for the skeletal ageing of children. This case study provides an opportunity to examine broader biocultural sources of adversity on skeletal growth in early life.

American Journal of Human Biology , Jan 23, 2016

This study investigates growth patterns in the scapula and clavicle in a cross-sectional juvenile... more This study investigates growth patterns in the scapula and clavicle in a cross-sectional juvenile skeletal sample ranging from 20 weeks gestation to 8.5 years of age from the Kellis 2 cemetery, Dakhleh Oasis, Egypt. The primary goal is to quantify growth patterns and growth velocities in the scapula and clavicle to better understand the
development of the pectoral girdle. A series of low-order polynomial regression models was used to examine growth curves in clavicle diaphyseal length, scapular height, and scapular width. Incremental growth and relative percent increase were examined among successive age groups as a proxy measure of growth velocity. Scapular body proportions were assessed with the scapular index and compared across age groups using a Kruskal–Wallis test with post-hoc tests. A third-order polynomial best describes growth in clavicle diaphyseal length and scapular height, and a second-order polynomial best describes growth in scapular width. Growth velocity patterns are similar among clavicle diaphyseal length, scapular height, and scapular width particularly from birth until the end of early childhood. Clavicle diaphyseal length decelerates during middle childhood while scapular height and width accelerate during this time. With increasing age, the scapular body proportionately increases more in height than in width. The relatively narrow scapular body characteristic of adult scapulae is first evident during early childhood. Changes in scapular body shape during ontogeny may be a reflection of the greater alterations taking place in the integrated morphology of the pectoral girdle during the biomechanical shift from crawling to bipedalism.

American Journal of Human Biology 26: 221-228, 2014

Objectives: The purpose of this study is to document the appearance of adult patterns in intralim... more Objectives: The purpose of this study is to document the appearance of adult patterns in intralimb indices during ontogeny in a skeletal sample from the Kellis 2 cemetery, Dakhleh Oasis, Egypt. In addition, this study explores evolvability in intralimb indices to understand relative differences in sensitivity to ecogeographic variables.

American Journal of Physical Anthropology 153(3): 496-505., 2014

Several studies have shown that the human body generally conforms to the ecogeographical expectat... more Several studies have shown that the human body generally conforms to the ecogeographical expectations of Bergmann's and Allen's rules; however, recent evidence suggests that these expectations may not hold completely for some populations. Egypt is located at the crossroads of Sub-Saharan Africa, Southern Europe, and the Near East, and gene flow among groups in these regions may confound ecogeographical patterning. In this study, we test the fit of the adult physique of a large sample (N = 163) of females and males from the Kellis 2 cemetery (Dakhleh Oasis, Egypt) against ecogeographical predictions. Body shape (i.e., body mass relative to stature) was assessed by the femur head diameter to bicondylar femur length index (FHD/BFL), and brachial and crural indices were calculated to examine intralimb proportions. Body shape in the Kellis 2 sample is not significantly different from high-latitude groups and a Lower Nubian sample, and intralimb proportions are not significantly different from mid-latitude and other low-latitude groups. This study demonstrates the potential uniqueness of body shape and intralimb proportions in an ancient Egyptian sample, and further highlights the complex relationship between ecogeographic patterning and adaptation. Am J Phys Anthropol 153:496–505, 2014. © 2013 Wiley Periodicals, Inc.

American Journal of Biological Anthropology, 2024

PaleoAnthropology, 2022

Reconstructing hominin evolution is dependent on our capacity to securely and accurately allocate... more Reconstructing hominin evolution is dependent on our capacity to securely and accurately allocate fossil hominin material to an appropriate taxon. While taxonomic assignments are traditionally based on craniodental morphology, structural analyses of unassociated hominin long bones have provided a means to deduce the taxonomic identity of isolated postcranial remains based on morphological comparisons with corresponding elements from craniodentally associated material. This study examines cross-sectional geometric properties in the mid-diaphyseal section in KNM-ER 1592, an unassociated femur from the KBS Member of the Koobi Fora Formation, Kenya. Hominin taxonomic diversity throughout this member has hindered attempts to taxonomically place KNM-ER 1592 based on stratigraphic location alone. The aim of this study is to infer the taxonomic identity of this femur based on morphometric comparisons with femora assigned to Australopithecus, Paranthropus, and Homo. Relationships between cortical area and total area, and differential bending rigidity along the anatomical planes of the midshaft femur were examined. Torsional and average bending strength in KNM-ER 1592 was compared to distributions in australopith, non-habilis early Homo, and H. naledi groups to further assess its midshaft structure in comparative context. The overall mid-diaphyseal femoral morphology in KNM-ER 1592 fits comfortably with patterns observed in non-habilis early Homo Pleistocene femora. KNM-ER 1592 shows an increase in cortical area for a given total area (i.e., relatively thick cortical bone) in the midshaft region like most pre-modern hominins. However, it displays a greater mediolateral relative to anteroposterior expanded mid-diaphyseal morphology characteristic of H. erectus and "erectus-like" femora, and its torsional and average bending strength further demonstrates its affinity with non-habilis early Homo. Based on the structural analyses of the mid-diaphyseal region, a tentative assignment of KNM-ER 1592 to genus Homo sp. indet. is supported. The alignment of KNM-ER 1592 with Homo is further supported when its overall cross-sectional size is also considered. Overlap among australopith and Homo samples at the smaller and intermediate size ranges is observed in both bivariate comparisons, but australopith and Homo samples do not overlap at the larger end of the size range where KNM-ER 1592 consistently falls with KNM-ER 803a and 1807. The former has been craniodentally aligned with H. erectus and the latter has been morphometrically aligned with H. erectus and "erectus-like" femora. Biomechanical analyses provide an avenue for which to test hypotheses about the taxonomic identity of isolated postcranial material based on morphological comparisons with material craniodentally attributed to a specific taxon.

HOMO-Journal of Comparative Human Anatomy, 2012

Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to... more Functional adaptations in femora attributed to Orrorin tugenensis provide a unique opportunity to examine locomotor behavior very early in the hominin lineage. This study examines relative cortical thickness, cortical area (CA) relative to the polar moment of area (J), and J relative to femoral head superoinferior diameter (FHD) in the proximal femur of O. tugenensis (BAR 1002'00 and BAR 1003'00), and compares patterns in this early hominin with those in a sample of modern humans (N = 31), Plio-Pleistocene fossil hominins (N = 8), Pan troglodytes troglodytes (N = 13), and Pan paniscus (N = 3). Relative cortical thickness and CA relative to J in the proximal femur of O. tugenensis are comparable to patterns generally found in other fossil hominins. Proximal femoral diaphyseal J relative to FHD in BAR 1002'00 is similar to patterns found in fossil hominins typically attributed to a non-Homo genus (i.e. SK 82, SK 97, and KNM-ER 738). Cross-sectional geometric patterns in the proximal femur of Orrorin are not unlike those generally found in australopithecines and fossil Homo. While the results of this study cannot confirm unequivocally that Orrorin was an obligate biped, a mode of locomotion comparable to that proposed for australopithecines cannot be ruled out.

This study explores locomotion and locomotor variability in Plio-Pleistocene hominins by examinin... more This study explores locomotion and locomotor variability in Plio-Pleistocene hominins by examining cross-sectional properties and mechanical loading patterns in the proximal and midshaft femur of Paranthropus, fossil Homo sp. and H. erectus. Modern human and Pan models are ...