Mark F Teaford

Touro University, California, College of Osteopathic Medicine · Basic Sciences

It is axiomatic that knowledge of the diets of extinct hominin species is central to any understanding of their ecology and our evolution. The importance of diet in the paleontological realm has led to the employment of multiple approaches in its elucidation. Some of these have deep historical roots, while others are dependent upon more recent tech...

Dental microwear analysis has been employed in studies of a wide range of modern and fossil animals, yielding insights into the biology/ecology of those taxa. Some researchers have suggested that dental microwear patterns ultimately relate back to the material properties of the foods being consumed, whereas others have suggested that, because exoge...

Wild primates face grave conservation challenges, with habitat loss and climate change projected to cause mass extinctions in the coming decades. As large-bodied Neotropical primates, mantled howling monkeys (Alouatta palliata) are predicted to fare poorly under climate change, yet are also known for their resilience in a variety of environments, i...

Objectives: This study seeks to determine if (a) consumption of hard food items or a mixture of food items leads to the formation of premolar or molar microwear in laboratory capuchin monkeys (Sapajus apella) in one feeding session and (b) rates of microwear formation are associated with the number of food items consumed. Materials and methods:...

Feeding and diet played key roles in human evolution. It is well known that modern humans have a small masticatory apparatus for their body size among primates. However, identifying gracility does not necessarily tell us about the relative functional capacities of the human masticatory system beyond the obvious size-related consequences. We conside...

A new study by Fraser et al (2018) urges the use of phylogenetic comparative methods, whenever possible, in analyses of mammalian tooth wear. We are concerned about this for two reasons. First, this recommendation may mislead the research community into thinking that phylogenetic signal is an artifact of some sort rather than a fundamental outcome...

Primate teeth have been used to gain many insights into primate behavior and evolution. However, the often indecipherable terminology in those analyses has limited the accessibility and general understanding of that work. This chapter presents a brief review of primate incisors, canines, premolars, and molars in order to give a glimpse of what we k...

The importance of diet in primate ecology has motivated the use of a variety of methods to reconstruct dietary habits of extinct hominin taxa. Dental microwear is one such approach that preserves evidence from consumed food items. This study is based on 44 specimens of Australopithecus africanus from Makapansgat and Sterkfontein, and 66 specimens o...

Dental microwear texture pattern has been associated with aspects of diet for a broad range of mammalian taxa. The basic idea is that soft, tough foods are sheared with a steeper angle of approach between opposing occlusal surfaces, whereas hard, brittle items are crushed with forces perpendicular to those surfaces; and this difference is manifeste...

Dental microwear textures have been examined for a broad range of extant primates to assess their efficacy for reconstructing diets of fossil species. To date though, no dental microwear texture data have been published for pitheciid molars, despite reported variation in degree of sclerocarpy and, by extension, the fracture properties of foods thes...

Poster Presentation at the 86th Annual Meeting of the American Association of Physical Anthropologists

More than half a century ago, Percy Butler touted the importance of analyzing teeth to understand their function in an evolutionary context. There have been many advances in the study of dental functional morphology since that time. Here we review the various approaches to characterizing and comparing occlusal form that have been developed, especia...

Objectives: Platyrrhine species differ in the extent to and the manner in which they use their incisors and canines during food ingestion. For example, Ateles uses its anterior teeth to process mechanically nondemanding soft fruits, while the sclerocarp-harvesting pitheciids rely extensively on these teeth to acquire and process more demanding foo...

Recent dental microwear studies have shown that fossil species differ from one another in texture attributes-both in terms of central tendency and dispersion. Most comparative studies used to interpret these results have relied on poorly provenienced museum samples that are not well-suited to consideration of within species variation in diet. Here...

This chapter tracks temporal and regional trends in health in the midregion of the Georgia Bight, a large embayment extending from northern coastal Atlantic Florida to North Carolina. The study erplores changes in health in precontact and contact-era na- tive populations that in historic times were known as Guale. Comparison of prehistoric foragers...

Free-ranging primates are confronted with the challenge of maintaining an optimal range of body temperatures within a thermally dynamic environment that changes daily, seasonally, and annually. While many laboratory studies have been conducted on primate thermoregulation, we know comparatively little about the thermal pressures primates face in the...

This is a ZIP archive of all .sur files for microwear surfaces of published in Scott et al (2012). Similar ZIP archives for all species analyzed are available at RUcore: http://rucore.libraries.rutgers.edu/search/.

The mandibular third premolar (P3) of Australopithecus afarensis is notable for extensive morphological variability (e.g., metaconid presence/absence, closure of the anterior fovea, root number) and temporal trends in crown length and shape change over its 700 Ka time range. Hominins preceding A. afarensis have unicuspid, mesiodistally elongated P3...

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 behavio...

Craniodental morphologies of early hominins have been widely perceived as having evolved to effectively process the generally harder food items that would have accompanied the expansion of drier, more open habitats from the Late Miocene into the Early Pliocene. In particular, it has been argued that Australopithecus anamensis may have been the firs...

Molar tooth morphology is generally said to reflect a compromise between phylogenetic and functional influences. Chimpanzee subspecies have been reported to exhibit differences in molar dimensions and nonmetric traits, but these have not been related to differences in their diets. And in fact, observations to date of the diets of chimpanzees have n...

Determining the diet of an extinct species is paramount in any attempt to reconstruct its paleoecology. Because the distribution and mechanical properties of food items may impact postcranial, cranial, mandibular, and dental morphologies related to their procurement, ingestion, and mastication, these anatomical attributes have been studied intensiv...

We lack a general understanding of how primates perform physiologically during feeding to cope with the challenges of their natural environments. We here discuss several methods for studying the ecological physiology of feeding in mantled howlers (Alouatta palliata) at La Pacifica, Costa Rica. Our initial physiological effort focuses on recording e...

Dental microwear has long been used as evidence concerning the diets of extinct species. Here, we present a comparative baseline series of dental microwear textures for a sample of 21 anthropoid primate species displaying interspecific and intraspecific dietary variability. Four dental microwear texture variables (complexity, anisotropy, textural f...

New World monkeys display a wide range of masticatory apparatus morphologies related to their diverse diets and feeding strategies. While primatologists have completed many studies of the platyrrhine masticatory apparatus, particularly morphometric analyses, we collectively acknowledge key shortcomings in our understanding of the function and evolu...

Many researchers have suggested that Australopithecus anamensis and Australopithecus afarensis were among the earliest hominins to have diets that included hard, brittle items. Here we examine dental microwear textures of these hominins for evidence of this. The molars of three Au. anamensis and 19 Au. afarensis specimens examined preserve unobscur...

Finite element analysis (FEA) is a potentially powerful tool by which the mechanical behaviors of different skeletal and dental designs can be investigated, and, as such, has become increasingly popular for biomechanical modeling and inferring the behavior of extinct organisms. However, the use of FEA to extrapolate from characterization of the mec...

Previous studies have shown that anatomy students who complete oral laboratory presentations believe they understand the material better and retain it longer than they otherwise would if they only took examinations on the material; however, we have found no studies that empirically test such outcomes. The purpose of this study was to assess the eff...

A diverse assemblage of large mammals is spatially and stratigraphically associated with Ardipithecus ramidus at Aramis. The most common species are tragelaphine antelope and colobine monkeys. Analyses of their postcranial remains situate them in a closed habitat. Assessment of dental mesowear, microwear, and stable isotopes from these and a wider...

Prehensile-tailed platyrrhines (atelines and Cebus) and procyonids (Potos) display bony tail features that have been functionally and adaptively linked to their prehensile behaviors, particularly the need to resist relatively greater bending and torsional stresses associated with supporting their body weight during suspensory postures. We compared...

Objectives: Variations in the hardness (H) and modulus (E) of human second molar enamel were previously reported to decrease by over 50% on moving from the occlusal surface to the dentin-enamel junction (DEJ) (Cuy, et al., 2002). The aim of this study is to expand this earlier effort and determine variations in mechanical properties for different t...

This study employs dental microwear texture analysis to reconstruct the diets of two families of subfossil lemurs from Madagascar, the archaeolemurids and megaladapids. This technique is based on three-dimensional surface measurements utilizing a white-light confocal profiler and scale-sensitive fractal analysis. Data were recorded for six texture...

Previous studies have shown that students who complete oral presentations in the anatomy laboratory believe they understand the material better and retain it longer; however, we have found no studies that empirically test such outcomes based on exam scores. The purpose of this study was to assess the effectiveness of oral lab presentations on exam...

Dental microwear features are examined in the extinct Smilodon fatalis and among 8 species of extant large carnivores, including felids, canids, hyaenids and a mustelid. Hyaenas are the most frequent bone-crushers and cheetahs the least. Because bone is harder than meat, interspectific differences in bone consumption are expected to be reflected by...

Teeth have provided insights into many topics including primate diet, paleobiology, and evolution, due to the fact that they are largely composed of inorganic materials and may remain intact long after an animal is deceased. Previous studies have reported that the mechanical properties, chemistry, and microstructure of human enamel vary with locati...

Although it is assumed that monkeys in some environments experience more nutritional or physiological stress than others, little research has been conducted on this topic. This study examines the relationship between linear enamel hypoplasia (LEH) frequency, a physiological indicator of stress, and environmental stressors. To test this relationship...

Construction in the City of Baltimore during 1996 led to the recovery of human skeletal remains dating from 1792 to 1856. Historical research indicates that the skeletal remains come from two adjacent graveyards: Christ's Church Episcopalian Cemetery and the Potters Field East. The different socioeconomic status of the internees in each cemetery su...

In vivo laboratory-based studies describing jaw-muscle activity and mandibular bone strain during mastication provide the empirical basis for most evolutionary hypotheses linking primate masticatory apparatus form to diet. However, the laboratory data pose a potential problem for testing predictions of these hypotheses because estimates of masticat...

Cranium of Paranthropus boisei (OH 5). Image courtesy of Donald C. Johanson. (4.76 MB TIF)

Palate and maxillary teeth of Paranthropus boisei (OH 5). Image courtesy of Donald C. Johanson. (1.54 MB TIF)

This document describes the paleoenvironmental contexts of the specimens analyzed in this study (0.06 MB DOC)

Specimens of Paranthropus boisei examined for this study. (0.04 MB DOC)

Geochronological age of Paranthropus boisei specimens employed in this study. (0.03 MB DOC)

[This corrects the article on p. e2044 in vol. 3, PMID: 18446200.].

The Plio-Pleistocene hominin Paranthropus boisei had enormous, flat, thickly enameled cheek teeth, a robust cranium and mandible, and inferred massive, powerful chewing muscles. This specialized morphology, which earned P. boisei the nickname "Nutcracker Man", suggests that this hominin could have consumed very mechanically challenging foods. It ha...

Several recent studies have stressed the role of dietary change in the origin and early evolution of our genus in Africa. Resulting models have been based on nutrition research and analogy to living peoples and nonhuman primates or on archeological and paleoenvironmental evidence. Here we evaluate these models in the context of the hominin fossil r...

While mechanisms of myofascial face pain are poorly understood, bruxism has been implicated in the maintenance of this painful disorder. This study evaluates whether evidence of one aspect of bruxism, tooth-grinding, is positively associated with pain severity, as predicted by a psychophysiological model, or negatively associated, as predicted by a...

Recent nanoindentation studies have demonstrated that the hardness and Young's modulus of human molar enamel decreases by more than 50% on moving from the occlusal surface to the dentine-enamel junction on cross-sectional samples. Possible sources of these variations are changes in local chemistry, microstructure, and prism orientation. This study...

Nearly all studies of dental microwear have focused on the incisors and molars, even though the canines and premolars could be particularly informative for those animals that use the canine/premolar complex to open or manipulate objects. This study evaluated the dental microwear patterns found on the anterior shearing facet of the first mandibular...

Fifty years ago, investigators realized they could gain insights into jaw movement and tooth-use through light-microscope analyses of wear patterns on teeth. Since then, numerous analyses of modern and fossil material have yielded insights into the evolution of tooth use and diet in a wide variety of animals. However, analyses of fossils and archeo...

Improvements in the primate fossil record, and in methods of data acquisition and analysis, have set the stage for new insights into the development, function, and evolution of hominoid teeth. This chapter is a brief review of recent advances. In essence, genetic analyses are changing our perspectives on the evolution of morphology, while improved...

Dental microwear analysis is commonly used to infer aspects of diet in extinct primates. Conventional methods of microwear analysis have usually been limited to two-dimensional imaging studies using a scanning electron microscope and the identification of apparent individual features. These methods have proved time-consuming and prone to subjectivi...

Molar microwear fabrics in extant mammals vary with diet and, more particularly, the physical properties of the items that are consumed. Praeanthropus afarensis is well represented in the fossil record over a prolonged and radiometrically controlled temporal span, and reasonably robust paleoecological reconstructions are available for the various l...

Previous animal experimental work evaluating the effects of dietary consistency on mastication was generally limited to studies of either mandibular structure or rates and types of tooth wear. Control groups fed hard diets (HD) consistently exhibited increased cortical remodeling and/or bone strength when compared to groups fed soft diets (SD). Res...

Features that are characteristic of early hominin jaws and teeth have been widely perceived as having evolved to process food items that likely accompanied the expansion of drier, more open habitats in the Late Miocene and Early Pliocene. 'Australopithecus' anamensis has been envisaged as having undergone a dietary shift to harder and more brittle...

There is a degree of correlation between dietary habits and dental microwear in extant primates, and this has enabled inferences to be made about prehistoric diets. Several techniques have been used to quantify microwear, but the comparability of results derived from each has not been demonstrated. Moreover, neither intra- nor interobserver error r...

Conventional wisdom ties the origin and early evolution of the genus Homo to environmental changes that occurred near the end of the Pliocene. The basic idea is that changing habitats led to new diets emphasizing savanna resources, such as herd mammals or underground storage organs. Fossil teeth provide the most direct evidence available for evalua...

Primate species often eat foods of different physical properties. This may have implications for tooth structure and wear in those species. The purpose of this study was to examine the mechanical defenses of leaves eaten by Alouatta palliata from different social groups at Hacienda La Pacifica in Costa Rica. Leaves were sampled from the home-ranges...

San Luis de Apalachee, one of a chain of Roman Catholic missions established in Spanish Florida (modern states of Georgia and Florida) in the sixteenth and seventeenth centuries, was the principal center of missionization of native populations in the Florida panhandle. Paleoethnobotanical remains yield evidence of production of various kinds of cro...

Reconstructing the diets of extinct hominins is essential to understanding the paleobiology and evolutionary history of our lineage. Dental microwear, the study of microscopic tooth-wear resulting from use, provides direct evidence of what an individual ate in the past. Unfortunately, established methods of studying microwear are plagued with low r...

The South African Plio-Pleistocene cave deposits have yielded a diverse cercopithecoid fauna. In this study, the possible dietary proclivities of these extinct species are examined using details of molar microwear. Although sample sizes are often small, wear patterns suggest possible temporal changes in the diets of Parapapio jonesi from Makapansga...

Investigators have used many techniques to understand diet and tooth use in prehistoric species. A promising new addition to the analytical arsenal is dental microwear analysis—the study of microscopic wear patterns on teeth. On-going work is proceeding on a number of fronts. Studies of modern animals are showing some of the limits of resolution of...

Paleoprimatologists depend on relationships between form and function of teeth to reconstruct the diets of fossil species. Most of this work has been limited to studies of unworn teeth. A new approach, dental topographic analysis, allows the characterization and comparison of worn primate teeth. Variably worn museum specimens have been used to cons...

Bulletin of the History of Medicine 78.3 (2004) 697-698 The tone of this book is set when the author says, "science almost always starts with some kind of fantasy" (p. 68). A sense of wonder and excitement permeates the text, giving readers a taste of the fun of solving osteological puzzles, and perceptive glimpses of how it is done. Skeletons in O...

The Miocene epoch witnessed an extensive radiation of ape (non-cercopithecoid catarrhine) taxa. In order to appreciate the extent of this radiation, we need to understand something of the dietary diversity of these forms. In this study, we compare the dental microwear of seventeen ape species ranging in time from the Early to the Middle and Late Mi...

Teeth are the most common elements in the mammalian fossil record. Thus it is not surprising that they have yielded many insights into the lives of extinct creatures. When researchers in the 1970s noted that subtle differences in molar tooth shape could be correlated with significant dietary differences (1–7), it opened the door for a vast array of...

Both the efficacy and mechanism of any effect of oral splint therapy for patients with temporomandibular disorders (TMDs) are a matter of controversy. To address these issues, this study tested the hypothesis that oral splints produce the most marked pain relief for those TMD patients with myofascial face pain (MFP) who also brux (i.e. grind or cle...

In this study we use molar microwear analyses to examine the trophic distinctions among various taxa of Malagasy subfossil lemurs. High resolution casts of the teeth of Megaladapis, Archaeolemur, Palaeopropithecus, Babakotia, and Hadropithecus were examined under a scanning electron microscope. Megaladapis was undoubtedly a browsing folivore, but t...

In this study we use molar microwear analyses to examine the trophic distinctions among various taxa of Malagasy subfossil lemurs. High resolution casts of the teeth of Megaladapis, Archaeolemur, Palaeopropithecus, Babakotia, and Hadropithecus were examined under a scanning electron microscope. Megaladapis was undoubtedly a browsing folivore, but t...