David J Daegling
Biographic Data
| ID | 587687 |
|---|---|
| NAME | David J Daegling |
| GIVEN NAMES | David J |
| FAMILY NAME | Daegling |
| SIGNATURE | DAEGLING D J |
| AFFILIATIONS | University of Florida |
| ORCID | 0000-0002-0108-8986 |
| VERIFIED | Yes |
| TOTAL WORKS | 65 |
| TOTAL CITATIONS | 719 |
| AUTHOR COUNT | 65 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1988 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 15 |
Phylogenetic Influence on Bone Material Stiffness in the Mandibles of Cercopithecid Primates
Correspondence Among Locomotor Profiles, Daily Stride Cycles, and Femoral Bone Robusticity in Taï Forest Cercopithecids
Baboons and the Paleobiology of Paranthropus
Daily Rest, Osteogenic Signals, and the Reconstruction of Human Activity Patterns From Skeletal Remains
Skeletal morphology is thought to provide a direct, if imprecise, means of inferring activity pattern in bioarchaeological and paleontological contexts. Given that bone is responsive to load histories, variation in daily activity is expected to impact the skeleton in predictable ways. Both the frequency and severity of daily loads have been shown to influence osteogenesis and, by extension, skeletal mass and robusticity. Consequently, population …
Problems with Paranthropus
The game of models: Dietary reconstruction in human evolution
Despite substantial additions to the paleontological record and unanticipated improvements in analytical techniques since the Journal of Human Evolution was first published, consensus on the diet of early hominin species remains elusive. For instance, the notable advances in the analyses of hominin dental microwear and stable isotopes have provided a plethora of data that have in some instances clouded what was once ostensibly a clear picture of …
Masticatory and ingestive effort in Procolobus verus, a small-bodied African colobine
Seed choice differs by sex in sooty mangabeys (Cercocebus atys)
Functional Inference in Paleoanthropology: Theory and Practice
Oral processing, sexual selection, and size variation in the circumorbital region of Colobus and Piliocolobus
OBJECTIVES: The function of the browridge in primates is a subject of enduring debate. Early studies argued for a role in resisting masticatory stresses, but recent studies have suggested sexual signaling as a biological role. We tested associations between circumorbital form, diet, oral processing, and social behavior in two species of colobus monkey-the king colobus (Colobus polykomos) and western red or bay colobus (Piliocolobus badius). MATER…
Diet, feeding behavior, and jaw architecture of Taï monkeys: Congruence and chaos in the realm of functional morphology
We review feeding and mandibular anatomy in a community of West African monkeys. We use field observations, food material property data, and skeletal specimens from the Ivory Coast's Taï Forest to explore the factors that shape mandibular architecture in colobines and cercopithecines. Despite excellent geographic control across our sample, the fit between bone form (as conventionally described) and functional activity (as we perceive it) is not s…
Fruit Selectivity in Anthropoid Primates: Size Matters
Long bone structural proportions and locomotor behavior in Cercopithecidae
Forest Floor Leaf Cover as a Barrier for Dust Accumulation in Tai National Park: Implications for Primate Dental Wear Studies
Spatial variation in mandibular bone elastic modulus and its effect on structural bending stiffness: A test case using the Taï Forest monkeys
Objectives We investigated how heterogeneity in material stiffness affects structural stiffness in the cercopithecid mandibular cortical bone. We assessed (1) whether this effect changes the interpretation of interspecific structural stiffness variation across four primate species, (2) whether the heterogeneity is random, and (3) whether heterogeneity mitigates bending stress in the jaw associated with food processing. Materials and methods The s…
The enduring puzzle of the human chin
Although modern humans are considered to be morphologically distinct from other living primates because of our large brains, dexterous hands, and bipedal gait, all of these features are found among extinct hominins. The chin, however, appears to be a uniquely modern human trait. Probably because of the chin's exclusivity, many evolutionary scenarios have been proposed to explain its origins. To date, researchers have developed adaptive hypotheses…
Symphyseal surface strain during in vitro human mandibular wishboning
OBJECTIVES: This research theoretically models and empirically records symphyseal surface strain during in vitro human mandibular wishboning (lateral transverse bending) in order to test one aspect of the hypothesis that the chin is an adaptive response to masticatory stresses. From a perspective of optimality, three questions were tested: 1) Do human mandibles function as curved beams during wishboning? 2) Is the presence of a chin associated wi…
Bone remodeling is reduced in high stress regions of the cercopithecoid mandible
OBJECTIVES: Independent lines of evidence suggest that osteonal bone remodeling is a function of both mechanical (i.e., changes in stress) and non-mechanical (i.e., metabolic needs related to calcium liberation) factors. The degree to which secondary bone reflects mechanical factors, however, is incompletely understood despite the common assumption that the stress environment mediates remodeling activity. Here, we investigate whether there are re…
Feeding and oral processing behaviors of two colobine monkeys in Tai Forest, Ivory Coast
Comparative biomechanics of Australopithecus sediba mandibles
Spatial patterning of bone stiffness in the anterior mandibular corpus of M acaca fascicularis: Implications for models of bone adaptation
Elastic modulus of bone from the anterior mandibular corpus was determined via microindentation in a mixed‐sex ontogenetic sample ( N = 14) of Macaca fascicularis . This investigation focused on the hypothesis that material heterogeneity in the macaque mandibular symphysis—provided an accounting of age and sex variation—is explicable as a means to homogenize strains in this region. Experimental data and theoretical models of masticatory loading i…
Microbial osteolysis in an Early Pleistocene hominin (Paranthropus robustus) from Swartkrans, South Africa
The relationship between bending stress and the shape of maxillary canines in cercopithecoid monkeys
Primate canines function in social displays but are also recruited for biting in agonistic encounters. Although the precise nature of the loads such behavior places on the canine crown is unknown, it is thought that bending is a major component of such loads. To date, modeling of canine bending strength has relied on idealized geometric representations. Accounting for the tapering of the crown as well as shape changes along an apical–basal axis p…
Ontogeny of material stiffness heterogeneity in the macaque mandibular corpus
Evidence is accumulating that bone material stiffness increases during ontogeny, and the role of elastic modulus in conditioning attributes of strength and toughness is therefore a focus of ongoing investigation. Developmental changes in structural properties of the primate mandible have been documented, but comparatively little is known about changes in material heterogeneity and their impact on biomechanical behavior. We examine a cross‐section…
Dietary variation and food hardness in sooty mangabeys ( Cercocebus atys ): Implications for fallback foods and dental adaptation
We present information on food hardness and monthly dietary changes in female sooty mangabeys ( Cercocebus atys ) in Tai Forest, Ivory Coast to reassess the hypothesis that thick molar enamel is parsimoniously interpreted as a response to consumption of hard foods during fallback periods. We demonstrate that the diet of sooty mangabeys varies seasonally, but that one food— Sacoglottis gabonensis —is the most frequently consumed food every month a…
Biomechanics of cross‐sectional size and shape in the hominoid mandibular corpus
Mandibular cross sections of Pan, Pongo, Gorilla, Homo , and two fossil specimens of Paranthropus were examined by computed tomography (CT) to determine the biomechanical properties of the hominoid mandibular corpus. Images obtained by CT reveal that while the fossil hominids do not differ significantly from extant hominoids in the relative contribution of compact bone to total subperiosteal area, the shape of the Paranthropus corpora indicates t…
Compact bone distribution and biomechanics of early hominid mandibles
This investigation explores the effects of compact bone distribution on the biomechanical properties of the postcanine mandibular corpus of the fossil hominid taxa Australopithecus africanus and Paranthropus robustus The mandibles of extant great apes, modern humans, and the fossil hominids are examined by computed tomography (CT), and compact bone contours are used to calculate cross‐sectional biomechanical properties (cortical area, second mome…
Mandibular morphology and diet in the genusCebus
Feeding, Diet, and Jaw Form in West African Colobus and Procolobus
Sex and age differences in the diet and ingestive behaviors of sooty mangabeys ( Cercocebus atys ) in the Tai forest, Ivory coast
Members of the Cercocebus ‐ Mandrillus clade are united by several morphological features, including expanded premolars which are argued to be associated with a preponderance of hard objects in the diet. We test the association between premolar expansion and hard object feeding by examining how different dental regions are used during food processing. We examined the diet and oral processing activities of sooty mangabeys ( Cercocebus atys ) in th…
Homoplasy and thick enamel in primates
Craniofacial biomechanics and functional and dietary inferences in hominin paleontology
The relationship of in vivo bone strain to mandibular corpus morphology in Macaca fascicularis
Functional morphology of the mangabey mandibular corpus: Relationship to dental specializations and feeding behavior
Recent molecular and morphological surveys suggest that mangabeys do not represent a monophyletic group. Specifically, Cercocebus is the sister taxon of Mandrillus , whereas Lophocebus forms an unresolved trichotomy with Papio and Theropithecus . The Cercocebus ‐ Mandrillus clade is characterized by skeletal and dental adaptations related to acquisition and processing of hard‐object foods that resist decomposition for months on the forest floor. …
Viewpoints: Feeding mechanics, diet, and dietary adaptations in early hominins
Inference of feeding adaptation in extinct species is challenging, and reconstructions of the paleobiology of our ancestors have utilized an array of analytical approaches. Comparative anatomy and finite element analysis assist in bracketing the range of capabilities in taxa, while microwear and isotopic analyses give glimpses of individual behavior in the past. These myriad approaches have limitations, but each contributes incrementally toward t…
Brief communication: Enamel thickness and durophagy in mangabeys revisited
The documentation of enamel thickness variation across primates is important because enamel thickness has both taxonomic and functional relevance. The Old World monkeys commonly referred to as mangabeys have figured prominently in investigations of feeding ecology and enamel thickness. In this article, we report enamel thickness values for four mangabey taxa ( Cercocebus atys , Cercocebus torquatus , Lophocebus aterrimus , and Lophocebus albigena…
Dietary variation and food hardness in sooty mangabeys ( Cercocebus atys ): Implications for fallback foods and dental adaptation
We present information on food hardness and monthly dietary changes in female sooty mangabeys ( Cercocebus atys ) in Tai Forest, Ivory Coast to reassess the hypothesis that thick molar enamel is parsimoniously interpreted as a response to consumption of hard foods during fallback periods. We demonstrate that the diet of sooty mangabeys varies seasonally, but that one food— Sacoglottis gabonensis —is the most frequently consumed food every month a…
Estimation of torsional rigidity in primate long bones
Elliptical Fourier analysis of symphyseal shape in great ape mandibles
Feeding and oral processing behaviors of two colobine monkeys in Tai Forest, Ivory Coast
Growth in the mandibles of African apes
Growth in the mandibles ofPan troglodytesandGorilla gorillawas examined by use of the line skeleton, a median axis technique for the analysis of complex shapes. Developmental changes in the corpus, ramus, gonial angle, coronoid and condylar processes were assessed to test the hypothesis thatGorillajaws are ontogenetically scaled variants of mandibular morphology inPan. Despite previous observations that aspects of facial morphology related to mas…
Primate Feeding and Foraging: Integrating Studies of Behavior and Morphology
Given that something as fundamental as food acquisition is subject to selection pressure, it follows that morphological and behavioral diversity among primates is reflective of a range of adaptations to diet, feeding, and foraging. The recognition of these adaptations, however, is operationally difficult because it is the interaction between morphological and ecological variables that serves to define the particular adaptation. Researchers have a…
Elastic modulus variation in mandibular bone: A microindentation study of Macaca fascicularis
We characterized the heterogeneous anisotropic elastic properties of mandibular bone in an adult female specimen of Macaca fascicularis using the technique of microindentation. This approach used an indenter of known mass and geometry to sample bone hardness at a spatial resolution in the order of 100 μm. Hardness values were converted to elastic modulus using empirically derived regression. We determined properties in alveolar, midcorpus, and ba…
Interspecific and intraspecific relationships between tooth size and jaw size in primates
Shape variation in the mandibular symphysis of apes: An application of a median axis method
Symphyseal contours in a sample of living and fossil apes were assessed by application of the line skeleton, a form of median axis transformation. While the line skeleton offers novel opportunities for the analysis of shape, this study reaffirms previous observations that the shape of the symphysis is highly variable within great ape species, such that symphyseal morphology is not useful as a taxonomic marker. There is also little indication that…
Dental wear among cercopithecid monkeys of the Taï forest, Côte d'Ivoire
Studies of dental macrowear can be useful for understanding masticatory and ingestive behavior, life history, and for inferring dietary information from the skeletal material of extinct and extant primates. Such studies to date have tended to focus on one or two teeth, potentially missing information that can be garnered through examination of wear patterns across the tooth row. Our study measured macrowear in the postcanine teeth of three sympat…
Functional significance of cortical bone distribution in anthropoid mandibles: An in vitro assessment of bone strain under combined loads
Local variation in cortical bone thickness in the postcanine mandibular corpus appears to be stereotypical among anthropoids. Specifically, at sections under the molars, lingually situated cortical bone is typically thinner than that along the lateral aspect. This pattern applies despite phylogenetic, dietary, and allometric differences among the anthropoids sampled to date. Demes et al. (Food Acquisition and Processing in Primates [ 1984 ] New Y…
Microbial osteolysis in an Early Pleistocene hominin (Paranthropus robustus) from Swartkrans, South Africa
Occlusal forces and mandibular bone strain: "Is the primate jaw "overdesigned
Finite element modelling of the function of the periodontium and surrounding alveolar bone suggests these tissues are subjected to unusually large strains in comparison with the bone of the basal mandibular corpus. These studies, in addition to certain experimental investigations, have led to the suggestion that the strains experienced in the basal mandibular corpus are not functionally important. Under this view, size and shape of the basal corp…
New mandible of Paranthropus robustus from Member 1, Swartkrans Formation, South Africa
The Cambridge guide to prehistoric man
Biomechanics of cross‐sectional size and shape in the hominoid mandibular corpus
Mandibular cross sections of Pan, Pongo, Gorilla, Homo , and two fossil specimens of Paranthropus were examined by computed tomography (CT) to determine the biomechanical properties of the hominoid mandibular corpus. Images obtained by CT reveal that while the fossil hominids do not differ significantly from extant hominoids in the relative contribution of compact bone to total subperiosteal area, the shape of the Paranthropus corpora indicates t…
Compact bone distribution and biomechanics of early hominid mandibles
This investigation explores the effects of compact bone distribution on the biomechanical properties of the postcanine mandibular corpus of the fossil hominid taxa Australopithecus africanus and Paranthropus robustus The mandibles of extant great apes, modern humans, and the fossil hominids are examined by computed tomography (CT), and compact bone contours are used to calculate cross‐sectional biomechanical properties (cortical area, second mome…
Mandibular morphology and diet in the genusCebus
Influence of teeth, alveoli, and periodontal ligaments on torsional rigidity in human mandibles
We investigated the influence of teeth, periodontal ligaments, and alveoli on the structural integrity of human mandibles loaded in torsion. Surface bone strain was recorded from the mandibular corpus below the first molar on each of four specimens. These specimens were loaded by an external force that caused primarily torsion about the long axis of the corpus, and bone strain was recorded under the following conditions: 1) all supporting structu…
Functional morphology of the human chin
The protruding chin is an attribute that defines modern Homo sapiens to the exclusion of all other primates, including fossil hominids. The functional significance of the chin has been contemplated for most of the 20th century, but as yet no compelling functional argument for its evolution has withstood careful scrutiny. Consequently, the human chin is often cited as an example of a nonadaptive trait. Past attempts to explain the chin in a functi…
Shape variation in the mandibular symphysis of apes: An application of a median axis method
Symphyseal contours in a sample of living and fossil apes were assessed by application of the line skeleton, a form of median axis transformation. While the line skeleton offers novel opportunities for the analysis of shape, this study reaffirms previous observations that the shape of the symphysis is highly variable within great ape species, such that symphyseal morphology is not useful as a taxonomic marker. There is also little indication that…
New mandible of Paranthropus robustus from Member 1, Swartkrans Formation, South Africa
The relationship of in vivo bone strain to mandibular corpus morphology in Macaca fascicularis
Growth in the mandibles of African apes
Growth in the mandibles ofPan troglodytesandGorilla gorillawas examined by use of the line skeleton, a median axis technique for the analysis of complex shapes. Developmental changes in the corpus, ramus, gonial angle, coronoid and condylar processes were assessed to test the hypothesis thatGorillajaws are ontogenetically scaled variants of mandibular morphology inPan. Despite previous observations that aspects of facial morphology related to mas…
Occlusal forces and mandibular bone strain: "Is the primate jaw "overdesigned
Finite element modelling of the function of the periodontium and surrounding alveolar bone suggests these tissues are subjected to unusually large strains in comparison with the bone of the basal mandibular corpus. These studies, in addition to certain experimental investigations, have led to the suggestion that the strains experienced in the basal mandibular corpus are not functionally important. Under this view, size and shape of the basal corp…
Biomechanics of torsion in the human mandible
Comparative investigations of mandibular function among primates have relied upon elementary structural models to estimate states of masticatory stress and strain. In these studies, mandibular corpus morphology is idealized as a homogeneous, isotropic symmetrical body of invariant geometry, and this morphological abstraction is used to infer relative levels of stress and strain in the jaw. In reality, none of the limiting conditions assumed by th…
Biomechanics of torsion in the human mandible
Comparative investigations of mandibular function among primates have relied upon elementary structural models to estimate states of masticatory stress and strain. In these studies, mandibular corpus morphology is idealized as a homogeneous, isotropic symmetrical body of invariant geometry, and this morphological abstraction is used to infer relative levels of stress and strain in the jaw. In reality, none of the limiting conditions assumed by th…
Terrestrial foraging and dental microwear inPapio ursinus
Elliptical Fourier analysis of symphyseal shape in great ape mandibles
Experimental observation, theoretical models, and biomechanical inference in the study of mandibular form
Experimental studies and mathematical models are disparate approaches for inferring the stress and strain environment in mammalian jaws. Experimental designs offer accurate, although limited, characterization of biomechanical behavior, while mathematical approaches (finite element modeling in particular) offer unparalleled precision in depiction of strain magnitudes, directions, and gradients throughout the mandible. Because the empirical (experi…
Feeding, Diet, and Jaw Form in West African Colobus and Procolobus
Estimation of torsional rigidity in primate long bones
Functional significance of cortical bone distribution in anthropoid mandibles: An in vitro assessment of bone strain under combined loads
Local variation in cortical bone thickness in the postcanine mandibular corpus appears to be stereotypical among anthropoids. Specifically, at sections under the molars, lingually situated cortical bone is typically thinner than that along the lateral aspect. This pattern applies despite phylogenetic, dietary, and allometric differences among the anthropoids sampled to date. Demes et al. (Food Acquisition and Processing in Primates [ 1984 ] New Y…
Relationship of strain magnitude to morphological variation in the primate skull
In a comparative study of variation in primate skulls, Wood and Lieberman ([ 2001 ] Am. J. Phys. Anthropol. 116: 13–25) proposed that a predictable relationship exists between in vivo bone‐strain magnitudes and the extent of morphological variation in skeletal structures. They hypothesized that regions subject to high strains are prone to enhanced levels of variation. Three questions are posed with respect to the plausibility of this hypothesis. …
Shaping primate evolution: Form, function and behavior
Mandibular Biomechanics and the Paleontological Evidence for the Evolution of Human Diet
Many Darwinian biologists accept that organisms and their constituent parts exhibit optimal design (given certain architectural, developmental, and phylogenetic constraints) so as to maximize reproductive survival. Strictly adaptationist approaches to explaining design perfection in biological has been rightly criticized as Panglossian storytelling (Gould and Lewontin, 1979), but there is ample evidence that the configurations of at least some mo…
Application of an image-based weighted measure of skeletal bending stiffness to great ape mandibles
Traditional measures of structural stiffness in the primate skeleton do not consider the heterogeneous material stiffness distribution of bone. This assumption of homogeneity introduces an unknown degree of error in estimating stiffness in skeletal elements. Measures of weighted stiffness can be developed by including heterogeneous grayscale variations evident in computed tomographic (CT) images. Since gray scale correlates with material stiffnes…
Interspecific and intraspecific relationships between tooth size and jaw size in primates
Functional morphology of the mangabey mandibular corpus: Relationship to dental specializations and feeding behavior
Recent molecular and morphological surveys suggest that mangabeys do not represent a monophyletic group. Specifically, Cercocebus is the sister taxon of Mandrillus , whereas Lophocebus forms an unresolved trichotomy with Papio and Theropithecus . The Cercocebus ‐ Mandrillus clade is characterized by skeletal and dental adaptations related to acquisition and processing of hard‐object foods that resist decomposition for months on the forest floor. …
Biology (55 works) · Primate Behavior and Ecology (48 works) · Anatomy (32 works) · Anatomy (29 works) · Zoology (29 works) · Evolution and Paleontology Studies (27 works) · Evolutionary biology (26 works) · Pleistocene-Era Hominins and Archaeology (25 works) · Medicine (22 works) · Orthodontics (22 works)