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Chapple SA, Skinner MM. A tooth crown morphology framework for interpreting the diversity of primate dentitions. Evol Anthropol 2023; 32:240-255. [PMID: 37486115 DOI: 10.1002/evan.21994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 03/25/2023] [Accepted: 06/19/2023] [Indexed: 07/25/2023]
Abstract
Variation in tooth crown morphology plays a crucial role in species diagnoses, phylogenetic inference, and the reconstruction of the evolutionary history of the primate clade. While a growing number of studies have identified developmental mechanisms linked to tooth size and cusp patterning in mammalian crown morphology, it is unclear (1) to what degree these are applicable across primates and (2) which additional developmental mechanisms should be recognized as playing important roles in odontogenesis. From detailed observations of lower molar enamel-dentine junction morphology from taxa representing the major primate clades, we outline multiple phylogenetic and developmental components responsible for crown patterning, and formulate a tooth crown morphology framework for the holistic interpretation of primate crown morphology. We suggest that adopting this framework is crucial for the characterization of tooth morphology in studies of dental development, discrete trait analysis, and systematics.
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Affiliation(s)
- Simon A Chapple
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Matthew M Skinner
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
- Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
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2
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Davies TW, Alemseged Z, Gidna A, Hublin JJ, Kimbel WH, Kullmer O, Spoor F, Zanolli C, Skinner MM. Accessory cusp expression at the enamel-dentine junction of hominin mandibular molars. PeerJ 2021; 9:e11415. [PMID: 34055484 PMCID: PMC8141287 DOI: 10.7717/peerj.11415] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/16/2021] [Indexed: 11/20/2022] Open
Abstract
Studies of hominin dental morphology frequently consider accessory cusps on the lower molars, in particular those on the distal margin of the tooth (C6 or distal accessory cusp) and the lingual margin of the tooth (C7 or lingual accessory cusp). They are often utilized in studies of hominin systematics, where their presence or absence is assessed at the outer enamel surface (OES). However, studies of the enamel-dentine junction (EDJ) suggest these traits may be more variable in development, morphology and position than previously thought. Building on these studies, we outline a scoring procedure for the EDJ expression of these accessory cusps that considers the relationship between these accessory cusps and the surrounding primary cusps. We apply this scoring system to a sample of Plio-Pleistocene hominin mandibular molars of Paranthropus robustus, Paranthropus boisei, Australopithecus afarensis, Australopithecus africanus, Homo sp., Homo habilis and Homo erectus from Africa and Asia (n = 132). We find that there are taxon-specific patterns in accessory cusp expression at the EDJ that are consistent with previous findings at the OES. For example, P. robustus M1s and M2s very often have a distal accessory cusp but no lingual accessory cusp, while H. habilis M1s and M2s show the opposite pattern. The EDJ also reveals a number of complicating factors; some apparent accessory cusps at the enamel surface are represented at the EDJ only by shouldering on the ridges associated with the main cusps, while other accessory cusps appear to have little or no EDJ expression at all. We also discuss the presence of double and triple accessory cusps, including the presence of a double lingual accessory cusp on the distal ridge of the metaconid in the type specimen of H. habilis (OH 7–M1) that is not clear at the OES due to occlusal wear. Overall, our observations, as well as our understanding of the developmental underpinnings of cusp patterning, suggest that we should be cautious in our comparisons of accessory cusps for taxonomic interpretations.
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Affiliation(s)
- Thomas W Davies
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Zeresenay Alemseged
- Department of Organismal Biology and Anatomy, University of Chicago, Chicago, Illinois, United States
| | - Agness Gidna
- Paleontology Unit, National Museum of Tanzania, Dar es Salaam, Tanzania
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Collège de France, Paris, France
| | - William H Kimbel
- Institute of Human Origins, and School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, United States
| | - Ottmar Kullmer
- Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Goethe University, Frankfurt, Germany.,Department of Palaeoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
| | - Fred Spoor
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Centre for Human Evolution Research, Department of Earth Sciences, Natural History Museum, London, United Kingdom.,Department of Anthropology, University College London, London, United Kingdom
| | - Clément Zanolli
- Univ. Bordeaux, CNRS, MCC, PACEA, UMR 5199, F-33600 Pessac, France
| | - Matthew M Skinner
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,School of Anthropology and Conservation, University of Kent, Canterbury, United Kingdom.,Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
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3
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Carayon D, Adhikari K, Monsarrat P, Dumoncel J, Braga J, Duployer B, Delgado M, Fuentes-Guajardo M, de Beer F, Hoffman JW, Oettlé AC, Donat R, Pan L, Ruiz-Linares A, Tenailleau C, Vaysse F, Esclassan R, Zanolli C. A geometric morphometric approach to the study of variation of shovel-shaped incisors. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 168:229-241. [PMID: 30267417 DOI: 10.1002/ajpa.23709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/20/2018] [Accepted: 08/23/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVES The scoring and analysis of dental nonmetric traits are predominantly accomplished by using the Arizona State University Dental Anthropology System (ASUDAS), a standard protocol based on strict definitions and three-dimensional dental plaques. However, visual scoring, even when controlled by strict definitions of features, visual reference, and the experience of the observer, includes an unavoidable part of subjectivity. In this methodological contribution, we propose a new quantitative geometric morphometric approach to quickly and efficiently assess the variation of shoveling in modern human maxillary central incisors (UI1). MATERIALS AND METHODS We analyzed 87 modern human UI1s by means of virtual imaging and the ASU-UI1 dental plaque grades using geometric morphometrics by placing semilandmarks on the labial crown aspect. The modern human sample was composed of individuals from Europe, Africa, and Asia and included representatives of all seven grades defined by the ASUDAS method. RESULTS Our results highlighted some limitations in the use of the current UI1 ASUDAS plaque, indicating that it did not necessarily represent an objective gradient of expression of a nonmetric tooth feature. Rating of shoveling tended to be more prone to intra- and interobserver bias for the highest grades. In addition, our analyses suggest that the observers were strongly influenced by the depth of the lingual crown aspect when assessing the shoveling. DISCUSSION In this context, our results provide a reliable and reproducible framework reinforced by statistical results supporting the fact that open scale numerical measurements can complement the ASUDAS method.
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Affiliation(s)
- Delphine Carayon
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France.,Faculté d'Odontologie, Université Montpellier I, France
| | - Kaustubh Adhikari
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, UK
| | - Paul Monsarrat
- Faculté d'Odontologie, Université Toulouse III-Paul Sabatier, Toulouse, France.,STROMALab, CNRS ERL 5311, EFS, INP-ENVT, Inserm, Université Toulouse III-Paul Sabatier, Toulouse, France
| | - Jean Dumoncel
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France
| | - José Braga
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France.,Evolutionary Studies Institute and School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Benjamin Duployer
- Centre Inter-universitaire de Recherche et d'Ingénierie des Matériaux, UMR 5085 CNRS, Université de Toulouse III-Paul Sabatier, Toulouse, France
| | - Miguel Delgado
- Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET, Buenos Aires, República Argentina.,División Antropología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, República Argentina
| | - Macarena Fuentes-Guajardo
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, UK.,Departamento de Tecnología Médica, Facultad de Ciencias de la Salud, Universidad de Tarapacá, Arica, Chile
| | - Frikkie de Beer
- Radiation Science Department, South African Nuclear Energy Corporation (Necsa), Pelindaba, South Africa
| | - Jakobus W Hoffman
- Radiation Science Department, South African Nuclear Energy Corporation (Necsa), Pelindaba, South Africa
| | - Anna C Oettlé
- Department of Anatomy, University of Pretoria, South Africa.,Department of Anatomy, Sefako Makgatho Health Sciences University, South Africa
| | - Richard Donat
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France.,Institut National de Recherches Archéologiques Préventives-St. Estève, Saint Estève, France
| | - Lei Pan
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China.,State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Nanjing, China
| | - Andres Ruiz-Linares
- Department of Genetics, Evolution and Environment, and UCL Genetics Institute, University College London, London, UK.,Ministry of Education Key Laboratory of Contemporary Anthropology and Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai, China.,Laboratory of Biocultural Anthropology, Law, Ethics, and Health (Centre National de la Recherche Scientifique and Etablissement Français du Sang, UMR-7268), Aix-Marseille University, Marseille, France
| | - Christophe Tenailleau
- Centre Inter-universitaire de Recherche et d'Ingénierie des Matériaux, UMR 5085 CNRS, Université de Toulouse III-Paul Sabatier, Toulouse, France
| | - Frédéric Vaysse
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France.,Faculté d'Odontologie, Université Toulouse III-Paul Sabatier, Toulouse, France
| | - Rémi Esclassan
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France.,Faculté d'Odontologie, Université Toulouse III-Paul Sabatier, Toulouse, France
| | - Clément Zanolli
- UMR 5288 CNRS, Université Toulouse III-Paul Sabatier, Toulouse, France
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4
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Ortiz A, Bailey SE, Schwartz GT, Hublin JJ, Skinner MM. Evo-devo models of tooth development and the origin of hominoid molar diversity. SCIENCE ADVANCES 2018; 4:eaar2334. [PMID: 29651459 PMCID: PMC5895448 DOI: 10.1126/sciadv.aar2334] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/28/2018] [Indexed: 06/08/2023]
Abstract
The detailed anatomical features that characterize fossil hominin molars figure prominently in the reconstruction of their taxonomy, phylogeny, and paleobiology. Despite the prominence of molar form in human origins research, the underlying developmental mechanisms generating the diversity of tooth crown features remain poorly understood. A model of tooth morphogenesis-the patterning cascade model (PCM)-provides a developmental framework to explore how and why the varying molar morphologies arose throughout human evolution. We generated virtual maps of the inner enamel epithelium-an indelibly preserved record of enamel knot arrangement-in 17 living and fossil hominoid species to investigate whether the PCM explains the expression of all major accessory cusps. We found that most of the variation and evolutionary changes in hominoid molar morphology followed the general developmental rule shared by all mammals, outlined by the PCM. Our results have implications for the accurate interpretation of molar crown configuration in hominoid systematics.
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Affiliation(s)
- Alejandra Ortiz
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, USA
| | - Shara E. Bailey
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY 10003, USA
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Gary T. Schwartz
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, USA
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
| | - Matthew M. Skinner
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig 04103, Germany
- School of Anthropology and Conservation, University of Kent, Canterbury CT2 7NR, UK
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5
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Ortiz A, Bailey SE, Hublin JJ, Skinner MM. Homology, homoplasy and cusp variability at the enamel-dentine junction of hominoid molars. J Anat 2017; 231:585-599. [PMID: 28718921 PMCID: PMC5603786 DOI: 10.1111/joa.12649] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2017] [Indexed: 12/25/2022] Open
Abstract
Evolutionary studies of mammalian teeth have generally concentrated on the adaptive and functional significance of dental features, whereas the role of development on phenotypic generation and as a source of variation has received comparatively little attention. The present study combines an evolutionary biological framework with state-of-the-art imaging techniques to examine the developmental basis of variation of accessory cusps. Scholars have long used the position and relatedness of cusps to other crown structures as a criterion for differentiating between developmentally homologous and homoplastic features, which can be evaluated with greater accuracy at the enamel-dentine junction (EDJ). Following this approach, we collected digital models of the EDJ and outer enamel surface of more than 1000 hominoid teeth to examine whether cusp 5 of the upper molars (UM C5) and cusps 6 and 7 of the lower molars (LM C6 and LM C7) were associated each with a common developmental origin across species. Results revealed that each of these cusps can develop in a variety of ways, in association with different dental tissues (i.e. oral epithelium, enamel matrix) and dental structures (i.e. from different cusps, crests and cingula). Both within and between species variability in cusp origin was highest in UM C5, followed by LM C7, and finally LM C6. The lack of any species-specific patterns suggests that accessory cusps in hominoids are developmentally homoplastic and that they may not be useful for identifying phylogenetic homology. An important and unanticipated finding of this study was the identification of a new taxonomically informative feature at the EDJ of the upper molars, namely the post-paracone tubercle (PPT). We found that the PPT was nearly ubiquitous in H. neanderthalensis and the small sample of Middle Pleistocene African and European humans (MPAE) examined, differing significantly from the low frequencies observed in all other hominoids, including Pleistocene and recent H. sapiens. We emphasize the utility of the EDJ for human evolutionary studies and demonstrate how features that look similar at the external surface may be the product of different developmental patterns. This study also highlights the importance of incorporating both developmental and morphological data into evolutionary studies in order to gain a better understanding of the evolutionary significance of dental and skeletal features.
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Affiliation(s)
- Alejandra Ortiz
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
| | - Shara E Bailey
- Department of Anthropology, Center for the Study of Human Origins, New York University, New York, NY, USA
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Matthew M Skinner
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- School of Anthropology and Conservation, University of Kent, Canterbury, UK
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6
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Ungar PS. Dental evidence for the diets of Plio-Pleistocene hominins. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 146 Suppl 53:47-62. [PMID: 22101687 DOI: 10.1002/ajpa.21610] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Diet is fundamental to the interaction between an organism and its environment, and is therefore an important key to understanding ecology and evolution. It should come as no surprise then that paleoanthropologists have put a great deal of effort into reconstructing the diets of Plio-Pleistocene hominins. Most of this effort has focused on teeth; these durable parts of the digestive system are usually the most commonly preserved elements in vertebrate fossil assemblages. In this article, I review much of this work. Tooth size, occlusal morphology, enamel thickness, and microstructure provide evidence for the physical properties of the foods to which a species was adapted. Dental microwear can offer insights into the properties of foods that an individual ate on a day-to-day basis. Taken together, these lines of evidence can offer important insights into early hominin food choices and adaptations. New methods of analysis and theoretical perspectives are improving our understanding of the diets of Australopithecus, Paranthropus, and early Homo, and promise further progress long into the future.
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Affiliation(s)
- Peter S Ungar
- Department of Anthropology, University of Arkansas, Fayetteville, AR 72701, USA.
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7
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Schmidt C, Ousley S, Schmidt M. Brief communication: correcting overestimation when determining two-dimensional occlusal area in human molars. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2011; 145:327-32. [PMID: 21469080 DOI: 10.1002/ajpa.21511] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 12/28/2010] [Indexed: 11/07/2022]
Abstract
The robustness index (RI) is determined by multiplying dental mesiodistal and buccolingual diameters, and is used to estimate occlusal area. However, because teeth are not rectangular its calculation consistently causes overestimations. Moreover, teeth, in particular molars, are not identically shaped so overestimations vary. The current study seeks to determine the extent to which overestimations are affected by tooth shape and to improve RI's efficacy. Initially, 120 molars were sorted into six shape groups, which were determined by hypocone/hypoconulid expression. Three maxillary and three mandibular shape groups were set using the Arizona State University Dental Anthropology System. ANOVA results determined that RI overestimations, which averaged around 20%, were not the same for each shape category. Maxillary molars with large hypocones and mandibular molars with no hypoconulids were overestimated significantly less than the other molar groups. Regression-based correction formulae were generated and applied to the original sample. These formulae far more precisely estimated tooth area than RI and there were no differences in estimation based upon tooth shape. A subsequent validation study of 24 additional molars was undertaken to test the formulae on teeth not from the original sample. Overestimation/underestimation averaged 0.5% and was about the same for each of the tooth shape groups. Finally, six new correction formulae were generated using all 144 molars. The correction formulae provide, what is termed here, an adjusted robustness index (ARI), and it is recommended that ARI is used in future studies of molar occlusal area.
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Affiliation(s)
- Christopher Schmidt
- Department of Anthropology, University of Indianapolis, Indianapolis, IN 46227, USA.
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8
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Singleton M, Rosenberger AL, Robinson C, O'neill R. Allometric and metameric shape variation in Pan mandibular molars: a digital morphometric analysis. Anat Rec (Hoboken) 2010; 294:322-34. [PMID: 21235007 DOI: 10.1002/ar.21315] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 08/19/2010] [Indexed: 11/06/2022]
Abstract
The predominance of molar teeth in fossil hominin assemblages makes the patterning of molar shape variation a topic of bioanthropological interest. Extant models are the principal basis for understanding dental variation in the fossil record. As the sister taxon to the hominin clade, Pan is one such model and the only widely accepted extant hominid model for both interspecific and intraspecific variation. To explore the contributions of allometric scaling and meristic variation to molar variation in Pan, we applied geometric shape analysis to 3D landmarks collected from virtual replicas of chimpanzee and bonobo mandibular molars. Multivariate statistical analysis and 3D visualization of metameric and allometric shape vectors were used to characterize shape differences and test the hypothesis that species of Pan share patterns of metameric variation and molar shape allometry. Procrustes-based shape variables were found to effectively characterize crown shape, sorting molars into species and tooth-row positions with ≥ 95% accuracy. Chimpanzees and bonobos share a common pattern of M(1) -M(2) metameric variation, which is defined by differences in the relative position of the metaconid, size of the hypoconulid, curvature of the buccal wall, and proportions of the basins and foveae. Allometric scaling of molar shape is homogeneous for M(1) and M(2) within species, but bonobo and chimpanzee allometric vectors are significantly different. Nevertheless, the common allometric shape trend explains most molar-shape differences between P. paniscus and P. troglodytes. When allometric effects are factored out, chimpanzee and bonobo molars are not morphometrically distinguishable. Implications for hominid taxonomy and dietary reconstruction are discussed.
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Affiliation(s)
- Michelle Singleton
- Department of Anatomy, Midwestern University, Downers Grove, Illinois 60515, USA.
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9
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Abstract
Previous research into tooth crown dimensions and cusp proportions has proved to be a useful way to identify taxonomic differences in Pliocene and Pleistocene fossil hominins. The present study has identified changes in both M(1) crown size and cusp proportions within the genus Homo, with M(1) overall crown size reduction apparently occurring in two main stages. The first stage (a reduction of ca. 17%) is associated with the emergence of Homo ergaster and Homo erectus sensu stricto. The second stage (a reduction of ca. 10%) occurs in Homo sapiens, but the reduced modern human M(1) tooth crown size was only attained in Upper Paleolithic times. The absolute sizes of the individual cusps are highly positively correlated with overall crown size and dental reduction produces a reduction in the absolute size of each of the cusps. Most of the individual cusps scale isometrically with crown size, but the paracone shows a negative allometric relationship, indicating that the reduction in paracone size is less than in the other M(1) cusps. Thus, the phylogenetically oldest cusp in the upper molars also seems to be the most stable cusp (at least in the M(1)). The most striking change in M(1) cusp proportions is a change in the relative size of the areas of the paracone and metacone. The combination of a small relative paracone and a large relative metacone generally characterizes specimens attributed to early Homo, and the presence of this character state in Australopithecus and Paranthropus suggests it may represent the primitive condition for the later part of the hominin clade. In contrast, nearly all later Homo taxa, with the exception of Homo antecessor, show the opposite condition (i.e. a relatively large paracone and a relatively small metacone). This change in the relationship between the relative sizes of the paracone and metacone is related to an isometric reduction of the absolute size of the metacone. This metacone reduction occurs in the context of relative stability in the paracone as crown size decreases. Among later Homo taxa, both Homo heidelbergensis and Homo neanderthalensis show a further reduction of the metacone and an enlargement of the hypocone. Fossil and contemporary H. sapiens samples show a trend toward increasing the relative size of the protocone and decreasing the relative size of the hypocone. In Europe, modern human M(1) cusp proportions are essentially reached during the Upper Paleolithic. Although some variation was documented among the fossil taxa, we suggest that the relative size of the M(1) paracone and metacone areas may be useful for differentiating the earliest members of our genus from subsequent Homo species.
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Affiliation(s)
- Rolf Quam
- Division of Anthropology, American Museum of Natural History, New York, NY 10024-5192, USA.
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10
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Kimbel WH, Delezene LK. “Lucy” redux: A review of research on Australopithecus afarensis. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2009; 140 Suppl 49:2-48. [PMID: 19890859 DOI: 10.1002/ajpa.21183] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- William H Kimbel
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287-4101, USA.
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