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Yi Z, Zanolli C, Liao W, Liang H, Yao Y, Tian C, Wang K, Xu G, Wang W. Enamel thickness in the deciduous postcanine dentition of fossil and extant Pongo. J Hum Evol 2024; 191:103493. [PMID: 38714076 DOI: 10.1016/j.jhevol.2024.103493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/01/2024] [Accepted: 01/02/2024] [Indexed: 05/09/2024]
Affiliation(s)
- Zhixing Yi
- Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China; Guangxi Academy of Sciences, Nanning, 530007, China
| | - Clément Zanolli
- Univ. Bordeaux, CNRS, MCC, PACEA, UMR 5199, F-33600, Pessac, France
| | - Wei Liao
- Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China
| | - Hua Liang
- Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China
| | - Yanyan Yao
- Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China; Anthropology Museum of Guangxi, Nanning, 530012, China
| | - Chun Tian
- Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China
| | - Kun Wang
- School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, 221116, China
| | - Guilin Xu
- Guangxi Academy of Sciences, Nanning, 530007, China; Key Laboratory of Beibu Gulf Environment Change and Resources Utilization of Ministry of Education, Nanning Normal University, Nanning, 530001, China.
| | - Wei Wang
- Institute of Cultural Heritage, Shandong University, Qingdao, 266237, China.
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Smith TM, Arora M, Austin C, Nunes Ávila J, Duval M, Lim TT, Piper PJ, Vaiglova P, de Vos J, Williams IS, Zhao JX, Green DR. Oxygen isotopes in orangutan teeth reveal recent and ancient climate variation. eLife 2024; 12:RP90217. [PMID: 38457350 PMCID: PMC10942278 DOI: 10.7554/elife.90217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2024] Open
Abstract
Studies of climate variation commonly rely on chemical and isotopic changes recorded in sequentially produced growth layers, such as in corals, shells, and tree rings, as well as in accretionary deposits-ice and sediment cores, and speleothems. Oxygen isotopic compositions (δ18O) of tooth enamel are a direct method of reconstructing environmental variation experienced by an individual animal. Here, we utilize long-forming orangutan dentitions (Pongo spp.) to probe recent and ancient rainfall trends on a weekly basis over ~3-11 years per individual. We first demonstrate the lack of any consistent isotopic enrichment effect during exclusive nursing, supporting the use of primate first molar teeth as environmental proxies. Comparisons of δ18O values (n=2016) in twelve molars from six modern Bornean and Sumatran orangutans reveal a high degree of overlap, with more consistent annual and bimodal rainfall patterns in the Sumatran individuals. Comparisons with fossil orangutan δ18O values (n=955 measurements from six molars) reveal similarities between modern and late Pleistocene fossil Sumatran individuals, but differences between modern and late Pleistocene/early Holocene Bornean orangutans. These suggest drier and more open environments with reduced monsoon intensity during this earlier period in northern Borneo, consistent with other Niah Caves studies and long-term speleothem δ18O records in the broader region. This approach can be extended to test hypotheses about the paleoenvironments that early humans encountered in southeast Asia.
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Affiliation(s)
- Tanya M Smith
- Griffith Centre for Social and Cultural Research, Griffith UniversitySouthportAustralia
- Australian Research Centre for Human Evolution, Griffith UniversitySouthportAustralia
| | - Manish Arora
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Christine Austin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount SinaiNew YorkUnited States
| | - Janaína Nunes Ávila
- Griffith Centre for Social and Cultural Research, Griffith UniversitySouthportAustralia
- School of the Environment, The University of QueenslandBrisbaneAustralia
| | - Mathieu Duval
- Australian Research Centre for Human Evolution, Griffith UniversitySouthportAustralia
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH)BurgosSpain
- Palaeoscience Labs, Department of Archaeology and History, La Trobe UniversityMelbourneAustralia
| | - Tze Tshen Lim
- Department of Geology, Universiti MalayaKuala LumpurMalaysia
| | - Philip J Piper
- School of Archaeology and Anthropology, The Australian National UniversityCanberraAustralia
| | - Petra Vaiglova
- Griffith Centre for Social and Cultural Research, Griffith UniversitySouthportAustralia
- Australian Research Centre for Human Evolution, Griffith UniversitySouthportAustralia
- School of Archaeology and Anthropology, The Australian National UniversityCanberraAustralia
| | - John de Vos
- Department of Geology, Naturalis Biodiversity CenterLeidenNetherlands
| | - Ian S Williams
- Research School of Earth Sciences, The Australian National UniversityCanberraAustralia
| | - Jian-xin Zhao
- Radiogenic Isotope Facility, School of the Environment, The University of QueenslandBrisbaneAustralia
| | - Daniel R Green
- Australian Research Centre for Human Evolution, Griffith UniversitySouthportAustralia
- Department of Human Evolutionary Biology, Harvard UniversityCambridgeUnited States
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Guatelli-Steinberg D, Renteria C, Grimm JR, Maeret Carpenter I, Arola DD, McGraw WS. How mangabey molar form differs under routine vs. fallback hard-object feeding regimes. PeerJ 2023; 11:e16534. [PMID: 38099313 PMCID: PMC10720418 DOI: 10.7717/peerj.16534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 11/07/2023] [Indexed: 12/17/2023] Open
Abstract
Background Components of diet known as fallback foods are argued to be critical in shaping primate dental anatomy. Such foods of low(er) nutritional quality are often non-preferred, mechanically challenging resources that species resort to during ecological crunch periods. An oft-cited example of the importance of dietary fallbacks in shaping primate anatomy is the grey-cheeked mangabey Lophocebus albigena. This species relies upon hard seeds only when softer, preferred resources are not available, a fact which has been linked to its thick dental enamel. Another mangabey species with thick enamel, the sooty mangabey Cercocebus atys, processes a mechanically challenging food year-round. That the two mangabey species are both thickly-enameled suggests that both fallback and routine consumption of hard foods are associated with the same anatomical feature, complicating interpretations of thick enamel in the fossil record. We anticipated that aspects of enamel other than its thickness might differ between Cercocebus atys and Lophocebus albigena. We hypothesized that to function adequately under a dietary regime of routine hard-object feeding, the molars of Cercocebus atys would be more fracture and wear resistant than those of Lophocebus albigena. Methods Here we investigated critical fracture loads, nanomechanical properties of enamel, and enamel decussation in Cercocebus atys and Lophocebus albigena. Molars of Cercopithecus, a genus not associated with hard-object feeding, were included for comparison. Critical loads were estimated using measurements from 2D µCT slices of upper and lower molars. Nanomechanical properties (by nanoindentation) and decussation of enamel prisms (by SEM-imaging) in trigon basins of one upper second molar per taxon were compared. Results Protocone and protoconid critical fracture loads were significantly greater in Cercocebus atys than Lophocebus albigena and greater in both than in Cercopithecus. Elastic modulus, hardness, and elasticity index in most regions of the crown were greater in Cercocebus atys than in the other two taxa, with the greatest difference in the outer enamel. All taxa had decussated enamel, but that of Cercocebus atys uniquely exhibited a bundle of transversely oriented prisms cervical to the radial enamel. Quantitative comparison of in-plane and out-of-plane prism angles suggests that decussation in trigon basin enamel is more complex in Cercocebus atys than it is in either Lophocebus albigena or Cercopithecus cephus. These findings suggest that Cercocebus atys molars are more fracture and wear resistant than those of Lophocebus albigena and Cercopithecus. Recognition of these differences between Cercocebus atys and Lophocebus albigena molars sharpens our understanding of associations between hard-object feeding and dental anatomy under conditions of routine vs. fallback hard-object feeding and provides a basis for dietary inference in fossil primates, including hominins.
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Affiliation(s)
- Debbie Guatelli-Steinberg
- Department of Anthropology, The Ohio State University, Columbus, OH, United States of America
- School of Anthropology and Conservation, University of Kent, Canterbury, Kent, United Kingdom
| | - Cameron Renteria
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, United States of America
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, United States of America
| | - Jack R. Grimm
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, United States of America
| | - Izabela Maeret Carpenter
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, United States of America
| | - Dwayne D. Arola
- Department of Materials Science and Engineering, University of Washington, Seattle, WA, United States of America
- Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, United States of America
- Department of Mechanical Engineering, University of Washington, Seattle, WA, United States of America
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA, United States of America
| | - W. Scott McGraw
- Department of Anthropology, The Ohio State University, Columbus, OH, United States of America
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Estimates of absolute crown strength and bite force in the lower postcanine dentition of Gigantopithecus blacki. J Hum Evol 2023; 175:103313. [PMID: 36709569 DOI: 10.1016/j.jhevol.2022.103313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/18/2022] [Accepted: 12/18/2022] [Indexed: 01/30/2023]
Abstract
Gigantopithecus blacki is hypothesized to have been capable of processing mechanically challenging foods, which likely required this species to have high dental resistance to fracture and/or large bite force. To test this hypothesis, we used two recently developed approaches to estimate absolute crown strength and bite force of the lower postcanine dentition. Sixteen Gigantopithecus mandibular permanent cheek teeth were scanned by micro-computed tomography. From virtual mesial cross-sections, we measured average enamel thickness and bi-cervical diameter to estimate absolute crown strength, and cuspal enamel thickness and dentine horn angle to estimate bite force. We compared G. blacki with a sample of extant great apes (Pan, Pongo, and Gorilla) and australopiths (Australopithecus anamensis, Australopithecus afarensis, Australopithecus africanus, Paranthropus robustus, and Paranthropus boisei). We also evaluated statistical differences in absolute crown strength and bite force between the premolars and molars for G. blacki. Results reveal that molar crown strength is absolutely greater, and molar bite force absolutely higher, in G. blacki than all other taxa except P. boisei, suggesting that G. blacki molars have exceptionally high resistance to fracture and the ability to generate exceptionally high bite force. In addition, G. blacki premolars have comparable absolute crown strength and larger bite force capabilities compared with its molars, implying possible functional specializations in premolars. The dental specialization of G. blacki could thus represent an adaptation to further facilitate the processing of mechanically challenging foods. While it is currently not possible to determine which types of foods were actually consumed by G. blacki through this study, direct evidence (e.g. dental chipping and microwear) left by the foods eaten by G. blacki could potentially lead to greater insights into its dietary ecology.
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Guatelli‐Steinberg D, Schwartz GT, O'Hara MC, Gurian K, Rychel J, McGraw WS. Molar form, enamel growth, and durophagy in Cercocebus and Lophocebus. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2022; 179:386-404. [PMCID: PMC9796247 DOI: 10.1002/ajpa.24592] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/20/2022] [Accepted: 06/29/2022] [Indexed: 05/29/2023]
Abstract
Objectives To test the hypothesis that differences in crown structure, enamel growth, and crown geometry in Cercocebus and Lophocebus molars covary with differences in the feeding strategies (habitual vs. fallback durophagy, respectively) of these two genera. Relative to Lophocebus molars, Cercocebus molars are predicted to possess features associated with greater fracture resistance and to differ in enamel growth parameters related to these features. Materials and Methods Sample proveniences are as follows: Cercocebus atys molars are from the Taï Forest, Ivory Coast; Lophocebus albigena molars are from a site north of Makoua, Republic of Congo; and a Lophocebus atterimus molar is from the Lomako Forest, Democratic Republic of Congo. For μCT scans on which aspects of molar form were measured, sample sizes ranged from 5 to 35 for Cercocebus and 3 to 12 for Lophocebus. A subsample of upper molars was physically sectioned to measure enamel growth variables. Results Partly as a function of their larger size, Cercocebus molars had significantly greater absolute crown strength (ACS) than Lophocebus molars, supporting the hypothesis. Greater crown heights in Cercocebus are achieved through faster enamel extension rates. Also supporting the hypothesis, molar flare and proportional occlusal basin enamel thickness were significantly greater in Cercocebus. Relative enamel thickness (RET), however, was significantly greater in Lophocebus. Discussion If ACS is a better predictor of fracture resistance than RET, then Cercocebus molars may be more fracture resistant than those of Lophocebus. Greater molar flare and proportional occlusal basin thickness might also afford Cercocebus molars greater fracture resistance.
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Affiliation(s)
| | - Gary T. Schwartz
- School of Human Evolution and Social Change and Institute of Human OriginsArizona State UniversityTempeArizonaUSA
| | - Mackie C. O'Hara
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
- School of Anthropology and ConservationUniversity of KentCanterburyUK
| | - Kaita Gurian
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
| | - Jess Rychel
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
| | - W. Scott McGraw
- Department of AnthropologyThe Ohio State UniversityColumbusOhioUSA
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Feeding ecology of the last European colobine monkey, Dolichopithecus ruscinensis. J Hum Evol 2022; 168:103199. [PMID: 35667203 DOI: 10.1016/j.jhevol.2022.103199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 11/23/2022]
Abstract
Currently, very little is known about the ecology of extinct Eurasian cercopithecids. Dietary information is crucial in understanding the ecological adaptations and diversity of extinct cercopithecids and the evolution of this family. For example, the colobine genus Dolichopithecus is represented by multiple large-bodied species that inhabited Eurasia during the Pliocene-Early Pleistocene. The available evidence, though limited, suggests semiterrestrial locomotion, which contrasts with most extant African and Asian colobines that exhibit morphological and physiological adaptations for arboreality and folivory. These differences raise questions regarding the dietary specialization of early colobine taxa and how/if that influenced their dispersion out of Africa and into Eurasia. To further our understanding of the ecology of Plio-Pleistocene cercopithecids, we characterized the dental capabilities and potential dietary adaptations of Dolichopithecus ruscinensis through dental topographic and enamel thickness analyses on an M1 from the locality of Serrat d'en Vacquer, Perpignan (France). We also assessed the feeding behavior of D. ruscinensis through dental microwear texture analysis on a broad sample of fossil molars from fossil sites in France, Greece, Bulgaria, and Romania. Dental topographic and enamel thickness analyses suggest that D. ruscinensis could efficiently process a wide range of foods. Results of the dental microwear texture analysis suggest that its diet ranged from folivory to the consumption of more mechanically challenging foods. Collectively, this suggests a more opportunistic feeding behavior for Dolichopithecus than characteristic of most extant colobines.
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O'Hara MC, Guatelli-Steinberg D. Reconstructing tooth crown heights and enamel caps: A comparative test of three existing methods with recommendations for their use. Anat Rec (Hoboken) 2022; 305:123-143. [PMID: 33843152 DOI: 10.1002/ar.24637] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/04/2021] [Accepted: 03/04/2021] [Indexed: 01/05/2023]
Abstract
Studies of enamel growth and thickness, whether in paleoanthropology, bioarchaeology, or primatology, require measurements of crown height (CH), cuspal enamel thickness (CET), average (AET), and/or regional enamel thickness (RegAET) on complete, unworn crowns. Yet because fully unworn crowns are uncommon, three methods to bolster sample sizes by reconstructing slightly worn teeth have been developed: Profile, Polynomial, and Pen Tool. Although these methods have been tested for accuracy, no study has yet directly compared the three methods to assess their performance across CH, CET, AET, and RegAET measurements. Moreover, it is currently unclear how accurate the methods are when reconstructing crowns with varying degrees of wear. The present study addresses this gap in our understanding of how these methods perform on four key dental measurements, evaluates the degree of wear for which accurate crown reconstructions can be completed, and offers recommendations for applying these methods. Here, the methods are compared on Paranthropus robustus mandibular molars, a sample chosen because it exhibits variable morphology, presenting a challenge for reconstruction methods. For minimally worn teeth, Profile, Polynomial, and Pen Tool methods can be employed (in that order) for all measurements except CET, which cannot be reliably measured on reconstructions. For teeth with wear that obliterates the nadir of the occlusal basin or dentin horns, CH and AET can be measured using Profile and Polynomial reconstructions; however, no other measurements or methods were reliable. Recommendations provided here will make it possible to increase sample sizes and replicability, enhancing studies of enamel thickness and growth.
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Affiliation(s)
- Mackie C O'Hara
- Department of Anthropology, The Ohio State University, Columbus, Ohio, USA
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Smith AL, Robinson C, Taylor AB, Panagiotopoulou O, Davis J, Ward CV, Kimbel WH, Alemseged Z, Ross CF. Comparative biomechanics of the Pan and Macaca mandibles during mastication: finite element modelling of loading, deformation and strain regimes. Interface Focus 2021; 11:20210031. [PMID: 34938438 PMCID: PMC8361577 DOI: 10.1098/rsfs.2021.0031] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2021] [Indexed: 10/17/2023] Open
Abstract
The mechanical behaviour of the mandibles of Pan and Macaca during mastication was compared using finite element modelling. Muscle forces were calculated using species-specific measures of physiological cross-sectional area and scaled using electromyographic estimates of muscle recruitment in Macaca. Loading regimes were compared using moments acting on the mandible and strain regimes were qualitatively compared using maps of principal, shear and axial strains. The enlarged and more vertically oriented temporalis and superficial masseter muscles of Pan result in larger sagittal and transverse bending moments on both working and balancing sides, and larger anteroposterior twisting moments on the working side. The mandible of Pan experiences higher principal strain magnitudes in the ramus and mandibular prominence, higher transverse shear strains in the top of the symphyseal region and working-side corpus, and a predominance of sagittal bending-related strains in the balancing-side mandible. This study lays the foundation for a broader comparative study of Hominidae mandibular mechanics in extant and fossil hominids using finite element modelling. Pan's larger and more vertical masseter and temporalis may make it a more suitable model for hominid mandibular biomechanics than Macaca.
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Affiliation(s)
- Amanda L. Smith
- Department of Anatomy, Pacific Northwest University of Health Sciences, 200 University Parkway, Yakima, WA 98901, USA
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 East 57th Street, Chicago, IL 60637, USA
| | - Chris Robinson
- Department of Biological Sciences, Bronx Community College, Bronx, NY 10453, USA
| | | | - Olga Panagiotopoulou
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, Melbourne, Victoria 3800, Australia
| | - Julian Davis
- Department of Engineering, University of Southern Indiana, 8600 University Boulevard, Evansville, IN 47712, USA
| | - Carol V. Ward
- Department of Pathology and Anatomical Sciences, One Hospital Drive, University of Missouri, Columbia, MO 65212, USA
| | - William H. Kimbel
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287-4101, USA
| | - Zeresenay Alemseged
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 East 57th Street, Chicago, IL 60637, USA
| | - Callum F. Ross
- Department of Organismal Biology and Anatomy, University of Chicago, 1027 East 57th Street, Chicago, IL 60637, USA
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Premolar enamel thickness and distribution of a Miocene hominid Lufengpithecus hudienensis compared with Pleistocene and extant hominids. J Hum Evol 2021; 157:103030. [PMID: 34274567 DOI: 10.1016/j.jhevol.2021.103030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 05/23/2021] [Accepted: 05/27/2021] [Indexed: 11/23/2022]
Abstract
Lufengpithecus hudienensis is a Late-Miocene hominid from the Yuanmou basin of southwestern China. Previous studies link Lufengpithecus to either the Sivapithecus-orangutan clade or a derived branch from the basal stem of the Hominidae. Despite a rich fossil assemblage, the taxonomy of L. hudienensis and its phylogenetic relationship with other hominids is still unclear. Enamel thickness in fossil and modern hominids can provide insights into taxonomy, phylogeny, and dietary reconstructions. In this study, 24 upper and lower L. hudienensis premolars were imaged using high-resolution microcomputed tomography. Three-dimensional average enamel thickness and relative enamel thickness (RET) indices, as well as whole-crown enamel distribution patterns were recorded for the L. hudienensis specimens and compared with a total of 113 specimens of fossil and extant apes and recent modern humans (RMH): fossil Pongo (n = 36), Gigantopithecus blacki (n = 21), Pan troglodytes (n = 11), Gorilla gorilla (n = 7), and RMH (n = 38). RET of the premolars of L. hudienensis was found to be similar to that of fossil Pongo, P. troglodytes, and G. gorilla, but less than Gi. blacki and RMH values. The distribution of enamel thickness shows a taxon-specific pattern for L. hudienensis, generally characterized by thicker enamel on the lateral wall than on the cusp apex, on the lingual cusp of the upper and buccal cusp of the lower premolars, with some differences with respect to fossil Pongo, Gi. blacki, P. troglodytes, and G. gorilla patterns. Additional characterizations of enamel thickness distribution patterns of the molars and other dental endostructural morphologies are needed to further explore the phylogenetic relationships of L. hudienensis with other hominids.
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Hu R, Zhao L. Molar crown formation times of fossil orangutan molars from Guangxi, China. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:315-326. [PMID: 33253429 DOI: 10.1002/ajpa.24183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 09/14/2020] [Accepted: 11/09/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVES We aimed to investigate molar enamel development in fossil orangutans from Guangxi and shed light on the evolution of Asian great apes. MATERIALS AND METHODS We collected 32 fossil orangutan molars, most of which were from Guangxi apothecaries and the Guangxi Daxin Heidong cave, and prepared histological sections of each molar. We then characterized aspects of dental development, including long period line periodicity, number of Retzius lines and lateral enamel formation time, cuspal enamel thickness, and enamel formation time. RESULTS The long period line periodicity in fossil orangutans ranged from 9 to 10 days (mean, 9.09 days). The molar lateral enamel formation time ranged from 1.48 to 3.17 years (540-1,152 days). Cuspal enamel thickness in fossil orangutan molars ranged from 949 to 2,535 μm, and cuspal enamel formation time ranged from 0.64 to 1.87 years. Molar enamel formation time of fossil orangutans ranged from 2.47 to 4.67 years. DISCUSSION Long-period line periodicity of fossil orangutans from Guangxi was within the variation range of extant orangutans, and the average long period line periodicity (9.09 days) of fossil orangutans from Guangxi in this study was lower than the values for extant orangutans (9.5 days) and fossil orangutans (10.9 days) from Sumatra and Vietnam. Orangutan enamel thickness may have gradually decreased from the Middle Pleistocene to Holocene. Crown formation time of fossil orangutans was slightly longer than that of extant orangutans, and the M1 emergence age of fossil orangutans from Guangxi was about 4-6 years. These findings might indicate the regional difference or evolutionary changes in orangutans since Pleistocene. Dental development of the Guangxi fossil orangutans were more similar to that of Asian Miocene apes, suggesting the closer evolutionary relationship of orangutans to Miocene Asian fossil apes.
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Affiliation(s)
- Rong Hu
- Institute of Anthropology, Department of Anthropology and Ethology, Xiamen University, Xiamen, China
| | - Lingxia Zhao
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Science, Beijing, China
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Yi Z, Liao W, Zanolli C, Wang W. A robust alternative to assessing three-dimensional relative enamel thickness for the use in taxonomic assessment. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:555-567. [PMID: 33247444 DOI: 10.1002/ajpa.24187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 10/18/2020] [Accepted: 11/04/2020] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Three-dimensional relative enamel thickness (3DRET) is important for assessing hypotheses about taxonomy, phylogeny, and dietary reconstruction for primates. However, its weaknesses have not been thoroughly investigated. Here, we analyze its weaknesses and propose an index aiming at better taxonomic discrimination. MATERIALS AND METHODS The dimensionless 3D index, ratio of enamel-thickness to dentine-thickness (3DRED), which is defined as the cubic root of the ratio of 3D average enamel thickness (3DAET) to 3D average dentine thickness (3DADT), is proposed here. To compare 3DRET and 3DRED and their sensitivity to voxel size, a fossil orangutan molar was scanned 14 times with different resolutions ranging from 10 to 50 μm. Enamel thickness analysis was carried out for each resultant digital model. In addition, enamel thickness measurements of 179 mandibular permanent molars (eight genera) were analyzed, followed by investigating the relationship between 3DRET and 3DAET and between 3DRED and 3DAET. RESULTS Regarding sensitivity, 3DRED is more robust than 3DRET. In addition, 3DRET is correlated with 3DAET by linear curve with regression coefficients approximating or larger than 0.8 in most cases, while 3DRED shows less correlation with 3DAET. Furthermore, there are clear separations between different taxa in the bivariate plot of 3DRED against 3DAET, indicative of the taxonomic value of 3DRED. CONCLUSION Under certain conditions, 3DRED promises to be a robust and reliable alternative to 3DRET in taxonomic study.
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Affiliation(s)
- Zhixing Yi
- School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Wei Liao
- School of Earth Sciences, China University of Geosciences, Wuhan, China.,Anthropology Museum of Guangxi, Nanning, China
| | - Clément Zanolli
- Laboratoire PACEA, UMR 5199 CNRS, Université de Bordeaux, Pessac, France
| | - Wei Wang
- Anthropology Museum of Guangxi, Nanning, China.,Institute of Cultural Heritage, Shandong University, Qingdao, China
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12
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Ortiz A, Schander-Triplett K, Bailey SE, Skinner MM, Hublin JJ, Schwartz GT. Enamel thickness variation in the deciduous dentition of extant large-bodied hominoids. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:500-513. [PMID: 32767577 DOI: 10.1002/ajpa.24106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 05/16/2020] [Accepted: 06/11/2020] [Indexed: 11/09/2022]
Abstract
OBJECTIVES Enamel thickness features prominently in hominoid evolutionary studies. To date, however, studies of enamel thickness in humans, great apes, and their fossil relatives have focused on the permanent molar row. Comparatively little research effort has been devoted to tissue proportions within deciduous teeth. Here we attempt to fill this gap by documenting enamel thickness variation in the deciduous dentition of extant large-bodied hominoids. MATERIALS AND METHODS We used microcomputed tomography to image dental tissues in 80 maxillary and 78 mandibular deciduous premolars of Homo sapiens, Pan troglodytes, Gorilla, and Pongo. Two-dimensional virtual sections were created from the image volumes to quantify average (AET) and relative (RET) enamel thickness, as well as its distribution across the crown. RESULTS Our results reveal no significant differences in enamel thickness among the great apes. Unlike the pattern present in permanent molars, Pongo does not stand out as having relatively thicker-enameled deciduous premolars than P. troglodytes and Gorilla. Humans, on the other hand, possess significantly thicker deciduous premolar enamel in comparison to great apes. Following expectations from masticatory biomechanics, we also find that the "functional" side (protocone, protoconid) of deciduous premolars generally possesses thicker enamel than the "nonfunctional" side. DISCUSSION Our study lends empirical support to anecdotal observations that patterns of AET and RET observed for permanent molars of large-bodied apes do not apply to deciduous premolars. By documenting enamel thickness variation in hominoid deciduous teeth, this study provides the comparative context to interpret rates and patterns of wear of deciduous teeth and their utility in life history reconstructions.
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Affiliation(s)
- Alejandra Ortiz
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA.,Center for the Study of Human Origins, Department of Anthropology, New York University, New York, New York, USA
| | - Katherine Schander-Triplett
- Barrett, The Honors College, College of Liberal Arts and Sciences, Arizona State University, Tempe, Arizona, USA
| | - Shara E Bailey
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, New York, USA.,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
| | - Jean-Jacques Hublin
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.,Collège de France, Paris, France
| | - Gary T Schwartz
- Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, Arizona, USA
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Lockey AL, Alemseged Z, Hublin JJ, Skinner MM. Maxillary molar enamel thickness of Plio-Pleistocene hominins. J Hum Evol 2020; 142:102731. [DOI: 10.1016/j.jhevol.2019.102731] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/19/2019] [Accepted: 12/02/2019] [Indexed: 11/30/2022]
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14
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Schwartz GT, McGrosky A, Strait DS. Fracture mechanics, enamel thickness and the evolution of molar form in hominins. Biol Lett 2020; 16:20190671. [PMID: 31964261 DOI: 10.1098/rsbl.2019.0671] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As the tissue most directly responsible for breaking down food in the oral cavity, the form and function of enamel is obviously of evolutionary significance in humans, non-human primates and other vertebrates. Accordingly, a standard metric, relative enamel thickness (RET), has been used for many decades to provide insights into vertebrate and human palaeobiology. Relatively thick enamel has evolved many times in vertebrates including hominoids (the group to which living humans and fossil hominins belong), and this pattern is thought to provide information about taxonomy, phylogeny, functional anatomy and diet. In particular, relatively thick enamel is thought to make tooth crowns strong so that they resist fractures associated with eating mechanically resistant foods. Here, we use current models of tooth biomechanics to show that RET is at best only moderately informative of function and diet in living hominoids and fossil hominins, and at worst provides misleading information. We propose a new metric, absolute crown strength, to assess the resistance of teeth to fracture, and identify what may be a novel characteristic of tooth strength in fossil hominins.
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Affiliation(s)
- Gary T Schwartz
- Institute of Human Origins, Arizona State University, Tempe, AZ, USA.,School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
| | - Amanda McGrosky
- Institute of Human Origins, Arizona State University, Tempe, AZ, USA.,School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA
| | - David S Strait
- Department of Anthropology, Washington University in St Louis, St Louis, MO, USA.,Palaeo-Research Institute, University of Johannesburg, Gauteng, South Africa
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15
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Enamel thickness and dental development in Rudapithecus hungaricus. J Hum Evol 2019; 136:102649. [DOI: 10.1016/j.jhevol.2019.102649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 08/05/2019] [Accepted: 08/05/2019] [Indexed: 11/19/2022]
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16
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MacLatchy L, Rossie J, Houssaye A, Olejniczak AJ, Smith TM. New hominoid fossils from Moroto II, Uganda and their bearing on the taxonomic and adaptive status of Morotopithecus bishopi. J Hum Evol 2019; 132:227-246. [PMID: 31203849 DOI: 10.1016/j.jhevol.2019.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 03/05/2019] [Accepted: 03/07/2019] [Indexed: 10/26/2022]
Abstract
The early Miocene site of Moroto II, Uganda has yielded some of the oldest known hominoid fossils. A new partial mandible (UMP MORII 03'551) is notable for its long tooth row and large, narrow M2 with well-developed cristids - a morphological combination previously unknown for large bodied catarrhines of the Early Miocene and suggesting folivory. The tooth proportions are compatible with belonging to the same taxon as the maxilla UMP 62-11, the holotype of Morotopithecus bishopi; likewise, the long tooth row and vertical planum of UMP MORII 03'551 suggest that it may represent the same taxon as mandible(s) UMP 66-01 and UMP 62-10. Canine size strongly suggests UMP MORII 03'551 is a female. Comparisons of the tooth crown morphology and tooth row proportions, relative enamel thickness, enamel-dentine junction morphology, long-period line periodicity, and dental wear patterns support significant morphological, developmental, and inferred dietary differentiation, and therefore generic-level distinctiveness, among Afropithecus, Morotopithecus and the Proconsul clade. An isolated M1 (UMP MORII 03'559) is morphologically dissimilar, and much smaller than the actual or inferred size of molars in UMP MORII 03'551, UMP 66-01 and UMP 62-10, supporting the presence of two hominoid taxa at Moroto II, M. bishopi and a smaller bodied proconsulid. Given the high level of body mass dimorphism inferred for Morotopithecus and other early Miocene catarrhines, the known postcrania from Moroto II could be attributable to either taxon. However, UMP MORII 03'551 and the femora UMP MORII 94'80 derive from the same stratigraphic interval, while the isolated M1 was deposited later, increasing the likelihood that the mandible and femora are from the same individual. These new fossils expand our understanding of the taxonomic and adaptive diversity of early Miocene catarrhines.
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Affiliation(s)
- Laura MacLatchy
- Department of Anthropology, University of Michigan, Ann Arbor, MI 48104, USA.
| | - James Rossie
- Department of Anthropology, S.U.N.Y. Stony Brook, Stony Brook, NY 11794, USA
| | - Alexandra Houssaye
- UMR 7179 CNRS/Muséum National d'Histoire Naturelle, Département Adaptations du Vivant, 57 Rue Cuvier CP-55, 75005 Paris, France
| | | | - Tanya M Smith
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA 02138, USA
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Thiery G, Guy F, Lazzari V. Enamel Distribution in 3D: Is Enamel Thickness More Uneven in the Upper Second Molars of Durophagous Hominoids? ACTA ACUST UNITED AC 2019. [DOI: 10.3166/bmsap-2019-0060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Enamel thickness is not uniform across the dental crown of primates. It has been suggested that enamel distribution could be used in taxonomy or for ecological inferences. For instance, the thickness of molar enamel in mammals consuming hard food is expected to be uneven, despite differing reports on extant and extinct apes. Overall estimations of average and relative enamel thickness may mask the details of enamel distribution in complex teeth such as molars. Investigating enamel distribution and its purported relationship with ecology or phylogeny would require more detailed assessments. This paper aims to assess whether apes that consume hard foods on a regular basis, such as Pongo pygmaeus, can be characterized by the evenness or unevenness of enamel thickness. To do so, we combined topographic maps and distribution histograms of enamel thickness with cumulative profiles of its variation, or “pachymetric profiles”. We investigated a sample of 25 unworn hominoid upper second molars scanned by X-ray microtomography, and further compared this to a sample of 32 cercopithecines and colobines. Topographic maps show uniformly thin enamel for Gorilla gorilla and Hylobates sp., unevenly thin enamel for Pan paniscus and Pan troglodytes, and unevenly thick enamel for Pongo pygmaeus. The skewness of enamel distribution does not distinguish between ape species, but does separate apes from OldWorld monkeys. Contrary to previous reports on OldWorld monkeys, the slope of enamel thickness profiles, or pachymetric slope, does not predict the diet of extant apes. However, it does separate the Pan genus, which is characterized by a higher pachymetric slope indicating more uneven enamel distribution compared to other apes. The uneven thickness of enamel distribution observed on topographic maps for P. pygmaeus is not supported by its low pachymetric slope, which instead indicates uniform enamel distribution. This discrepancy in the results obtained for P. pygmaeus can be interpreted as an evolutionary tradeoff between fine-scale versus overall enamel distribution. On the one hand, unevenly thick enamel at a fine scale, combined with strongly decussated enamel as observed in P. pygmaeus, is expected to increase local resistance to crack propagation. On the other hand, uniformly thick enamel at the overall scale would improve the overall resilience of the enamel in coping with challenging food on a daily basis. Although understanding the effects of ecology on enamel distribution in apes requires further investigation, the results presented in this paper confirm the interest of enamel distribution for taxonomy and phylogeny.
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O'Hara MC, Le Cabec A, Xing S, Skinner MF, Guatelli‐Steinberg D. Safe Casting and Reliable Cusp Reconstruction Assisted by Micro‐Computed Tomographic Scans of Fossil Teeth. Anat Rec (Hoboken) 2019; 302:1516-1535. [DOI: 10.1002/ar.24047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 08/16/2018] [Accepted: 10/08/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Mackie C. O'Hara
- Department of Anthropology The Ohio State University Columbus Ohio 43210 USA
| | - Adeline Le Cabec
- Department of Human Evolution Max Planck Institute for Evolutionary Anthropology D‐04103 Leipzig Germany
| | - Song Xing
- Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences Beijing 100044 China
- CAS Center for Excellence in Life and Paleoenvironment Beijing 100044 China
| | - Mark F. Skinner
- Department of Archaeology, King's Manor University of York York UK, YO1 7EP
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19
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Lins PGADS, Ferreira RG. Competition during sugarcane crop raiding by blond capuchin monkeys (Sapajus flavius). Primates 2018; 60:81-91. [DOI: 10.1007/s10329-018-0698-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 11/07/2018] [Indexed: 12/26/2022]
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20
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Smith TM, Houssaye A, Kullmer O, Le Cabec A, Olejniczak AJ, Schrenk F, de Vos J, Tafforeau P. Disentangling isolated dental remains of Asian Pleistocene hominins and pongines. PLoS One 2018; 13:e0204737. [PMID: 30383758 PMCID: PMC6211657 DOI: 10.1371/journal.pone.0204737] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/13/2018] [Indexed: 11/18/2022] Open
Abstract
Scholars have debated the taxonomic identity of isolated primate teeth from the Asian Pleistocene for over a century, which is complicated by morphological and metric convergence between orangutan (Pongo) and hominin (Homo) molariform teeth. Like Homo erectus, Pongo once showed considerable dental variation and a wide distribution throughout mainland and insular Asia. In order to clarify the utility of isolated dental remains to document the presence of hominins during Asian prehistory, we examined enamel thickness, enamel-dentine junction shape, and crown development in 33 molars from G. H. R. von Koenigswald's Chinese Apothecary collection (11 Sinanthropus officinalis [= Homo erectus], 21 "Hemanthropus peii," and 1 "Hemanthropus peii" or Pongo) and 7 molars from Sangiran dome (either Homo erectus or Pongo). All fossil teeth were imaged with non-destructive conventional and/or synchrotron micro-computed tomography. These were compared to H. erectus teeth from Zhoukoudian, Sangiran and Trinil, and a large comparative sample of fossil Pongo, recent Pongo, and recent human teeth. We find that Homo and Pongo molars overlap substantially in relative enamel thickness; molar enamel-dentine junction shape is more distinctive, with Pongo showing relatively shorter dentine horns and wider crowns than Homo. Long-period line periodicity values are significantly greater in Pongo than in H. erectus, leading to longer crown formation times in the former. Most of the sample originally assigned to S. officinalis and H. erectus shows greater affinity to Pongo than to the hominin comparative sample. Moreover, enamel thickness, enamel-dentine junction shape, and a long-period line periodicity value in the "Hemanthropus peii" sample are indistinguishable from fossil Pongo. These results underscore the need for additional recovery and study of associated dentitions prior to erecting new taxa from isolated teeth.
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Affiliation(s)
- Tanya M. Smith
- Australian Research Centre for Human Evolution, Griffith University, Nathan, Queensland, Australia
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Alexandra Houssaye
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- ESRF—The European Synchrotron, Grenoble, France
- Département Adaptations du Vivant, UMR 7179 CNRS, Muséum National d’Histoire Naturelle, Paris, France
| | - Ottmar Kullmer
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt a.M., Germany
- Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Frankfurt a.M., Germany
| | - Adeline Le Cabec
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- ESRF—The European Synchrotron, Grenoble, France
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Friedemann Schrenk
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt a.M., Germany
- Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Frankfurt a.M., Germany
| | - John de Vos
- Department of Geology, Naturalis Biodiversity Center, Leiden, The Netherlands
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21
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Al-Amery SM, Nambiar P, John J, Purmal K, Ngeow WC, Mohamed NH, Vellayan S. Unusual Dental Morphology in a Chimpanzee: A Case Report Utilizing Cone-Beam Computed Tomography. J Vet Dent 2018; 35:96-102. [DOI: 10.1177/0898756418776448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This case report illustrates the teeth morphology of a chimpanzee and its anatomical variations. A well-preserved skull of a male Pan troglodytes troglodyte chimpanzee was scanned using a cone-beam computed tomography machine. Measurements included tooth and crown height, root length, root canal length and width (posterior teeth), and pulp cavity length (anterior teeth). Nonmetrical parameters included number of canals and foramina per root of every root. Interestingly, the mandibular central incisor was longer than the lateral incisor, and all the mandibular anterior teeth presented with a solitary flame-shaped or conical-calcified structure in their pulp cavity. The premolars are usually dual rooted except for the first maxillary premolar that displayed 3 roots. Other unusual discoveries were the presence of bilateral radicular dens invaginatus in the mandibular first premolars and the possibility of having 2 canals and 2 foramina in the roots of the posterior teeth. The presence of conical stone mineralizations at the pulp cavity and the presence of dens invaginatus were of particular interest.
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Affiliation(s)
- Samah M. Al-Amery
- Faculty of Dentistry, Department of Oro-Maxillofacial Surgical and Medical Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Phrabhakaran Nambiar
- Faculty of Dentistry, Department of Oro-Maxillofacial Surgical and Medical Sciences, University of Malaya, Kuala Lumpur, Malaysia
- Faculty of Dentistry, MAHSA University, Saujana Putra, Malaysia
| | - Jacob John
- Faculty of Dentistry, Department of Restorative Dentistry, University of Malaya, Kuala Lumpur, Malaysia
| | | | - Wei Cheong Ngeow
- Faculty of Dentistry, Department of Oro-Maxillofacial Surgical and Medical Sciences, University of Malaya, Kuala Lumpur, Malaysia
| | - Nor Himazian Mohamed
- Faculty of Dentistry, Department of Restorative Dentistry, University of Malaya, Kuala Lumpur, Malaysia
| | - Subramaniam Vellayan
- Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam, Kuala Selangor, Selangor, Malaysia
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22
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An early modern human presence in Sumatra 73,000–63,000 years ago. Nature 2017; 548:322-325. [DOI: 10.1038/nature23452] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/29/2017] [Indexed: 12/21/2022]
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23
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Skinner MF, Skinner MM. Orangutans, enamel defects, and developmental health: A comparison of Borneo and Sumatra. Am J Primatol 2017; 79. [DOI: 10.1002/ajp.22668] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2016] [Revised: 01/13/2017] [Accepted: 03/14/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Mark F. Skinner
- Department of Archaeology, King's Manor; University of York; York United Kingdom
| | - Matthew M. Skinner
- School of Anthropology and Conservation; University of Kent; Canterbury United Kingdom
- Department of Human Evolution; Max Planck Institute for Evolutionary Anthropology; Leipzig Germany
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24
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Smith TM. Dental development in living and fossil orangutans. J Hum Evol 2016; 94:92-105. [DOI: 10.1016/j.jhevol.2016.02.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 12/29/2015] [Accepted: 02/25/2016] [Indexed: 10/22/2022]
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25
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Tshen LT. Biogeographic distribution and metric dental variation of fossil and living orangutans (Pongo spp.). Primates 2015; 57:39-50. [DOI: 10.1007/s10329-015-0493-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 09/04/2015] [Indexed: 10/23/2022]
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26
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Enamel thickness trends in Plio-Pleistocene hominin mandibular molars. J Hum Evol 2015; 85:35-45. [DOI: 10.1016/j.jhevol.2015.03.012] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 11/14/2014] [Accepted: 03/25/2015] [Indexed: 11/21/2022]
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27
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Zanolli C, Grine FE, Kullmer O, Schrenk F, Macchiarelli R. The early Pleistocene deciduous hominid molar FS-72 from the Sangiran dome of java, Indonesia: A taxonomic reappraisal based on its comparative endostructural characterization. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 157:666-74. [DOI: 10.1002/ajpa.22748] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/02/2015] [Accepted: 03/10/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Clément Zanolli
- Multidisciplinary Laboratory; International Centre for Theoretical Physics; Trieste Italy
| | - Frederick E. Grine
- Department of Anthropology; Stony Brook University; Stony Brook NY
- Department of Anatomical Sciences; Stony Brook University; Stony Brook NY
| | - Ottmar Kullmer
- Department of Palaeoanthropology; Senckenberg Research Institute; Frankfurt Am Main Germany
| | - Friedemann Schrenk
- Department of Palaeoanthropology; Senckenberg Research Institute; Frankfurt Am Main Germany
- Department of Vertebrate Paleontology; Johann Wolfgang Goethe University; Frankfurt Germany
| | - Roberto Macchiarelli
- Département De Préhistoire; UMR 7194; Muséum National D'histoire Naturelle; Paris France
- Département Géosciences; Université De Poitiers; Poitiers France
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28
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Enamel thickness variation of deciduous first and second upper molars in modern humans and Neanderthals. J Hum Evol 2014; 76:83-91. [PMID: 25282273 DOI: 10.1016/j.jhevol.2014.05.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 03/31/2014] [Accepted: 05/08/2014] [Indexed: 11/20/2022]
Abstract
Enamel thickness and dental tissue proportions have been recognized as effective taxonomic discriminators between Neanderthal and modern humans teeth. However, most of the research on this topic focused on permanent teeth, and little information is available for the deciduous dentition. Moreover, although worn teeth are more frequently found than unworn teeth, published data for worn teeth are scarce and methods for the assessment of their enamel thickness need to be developed. Here, we addressed this issue by studying the 2D average enamel thickness (AET) and 2D relative enamel thickness (RET) of Neanderthal and modern humans unworn to moderately worn upper first deciduous molars (dm(1)s) and upper second deciduous molars (dm(2)s). In particular, we used 3D μCT data to investigate the mesial section for dm(1)s and both mesial and buccal sections for dm(2)s. Our results confirmed previous findings of an Neanderthal derived condition of thin enamel, and thinner enamel in dm(1)s than dm(2)s in both Neanderthal and modern humans. We demonstrated that the Neanderthal 2D RET indices are significantly lower than those of modern humans at similar wear stages in both dm(1)s and dm(2)s (p < 0.05). The discriminant analysis showed that using 2D RET from dm(1) and dm(2) sections at different wear stages up to 93% of the individuals are correctly classified. Moreover, we showed that the dm(2) buccal sections, although non-conventionally used, might have an advantage on mesial sections since they distinguish as well as mesial sections but tend to be less worn. Therefore, the 2D analysis of enamel thickness is suggested as a means for taxonomic discrimination between modern humans and Neanderthal unworn to moderately worn upper deciduous molars.
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Kato A, Tang N, Borries C, Papakyrikos AM, Hinde K, Miller E, Kunimatsu Y, Hirasaki E, Shimizu D, Smith TM. Intra- and interspecific variation in macaque molar enamel thickness. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 155:447-59. [PMID: 25146639 DOI: 10.1002/ajpa.22593] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 08/04/2014] [Accepted: 08/05/2014] [Indexed: 11/06/2022]
Abstract
Enamel thickness has played an important role in studies of primate taxonomy, phylogeny, and functional morphology, although its variation among hominins is poorly understood. Macaques parallel hominins in their widespread geographic distribution, relative range of body sizes, and radiation during the last five million years. To explore enamel thickness variation, we quantified average and relative enamel thickness (AET and RET) in Macaca arctoides, Macaca fascicularis, Macaca fuscata, Macaca mulatta, Macaca nemestrina, and Macaca sylvanus. Enamel area, dentine area, and enamel-dentine junction length were measured from mesial sections of 386 molars scanned with micro-computed tomography, yielding AET and RET indices. Intraspecific sex differences were not found in AET or RET. Macaca fuscata had the highest AET and RET, M. fascicularis showed the lowest AET, and M. arctoides had the lowest RET. The latitudinal distribution of macaque species was associated with AET for these six species. Temperate macaques had thicker molar enamel than did tropical macaques, suggesting that thick enamel may be adaptive in seasonal environments. Additional research is needed to determine if thick enamel in temperate macaques is a response to intensified hard-object feeding, increased abrasion, and/or a broader diet with a greater range of food material properties. The extreme ecological flexibility of macaques may prohibit identification of consistent trends between specific diets and enamel thickness conditions. Such complications of interpretation of ecological variability, dietary diversity, and enamel thickness may similarly apply for fossil Homo species.
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Affiliation(s)
- Akiko Kato
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, 02138; Department of Oral Anatomy, School of Dentistry, Aichi Gakuin University, Nagoya, 4648650, Japan
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Vogel ER, Zulfa A, Hardus M, Wich SA, Dominy NJ, Taylor AB. Food mechanical properties, feeding ecology, and the mandibular morphology of wild orangutans. J Hum Evol 2014; 75:110-24. [PMID: 25038032 DOI: 10.1016/j.jhevol.2014.05.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 05/14/2014] [Accepted: 05/16/2014] [Indexed: 10/25/2022]
Abstract
Bornean orangutan mandibular morphology has been functionally linked to the exploitation of hard and tough foods, based on evidence that Pongo pygmaeus wurmbii spends a greater percentage of time feeding on bark, seeds and vegetation compared with Pongo abelii (Sumatran orangutans) and the assumption that these tissues are more challenging to process than fruit pulp. We measured and compared toughness (R) and Young's modulus (E) of ripe and unripe foods exploited by P. abelii and P. p. wurmbii. Additionally, we recorded and compared the percentage of time these orangutans fed on plants/plant parts of varying degrees of R and E. Compared with P. abelii, P. p. wurmbii consumed significantly tougher and more displacement limited (R/E)(0.5) fruit parts, leaves and inner bark, and spent a significantly greater percentage of time feeding on immature leaves, unripe fruit and other vegetation. Modulus did not vary as expected between species, likely because we failed to capture the high-end range of modulus values for tissues consumed by P. p. wurmbii. Notably, P. p. wurmbii spent ∼40% of its feeding time on the toughest foods consumed (between 1000 and 4000 J m(-2)). Thus, the hypothesis that mandibular robusticity in P. p. wurmbii is functionally linked to feeding on tough foods is supported and is likely related to countering relatively larger external forces and/or repetitive loads required to process the toughest tissues. The importance of elastic modulus on morphological divergence awaits future studies capturing the full range of this material property for P. p. wurmbii. Finally, phenophase and fruit availability influence orangutan species differences in food material properties and percentage of time spent feeding on various foods, emphasizing the importance of incorporating these variables in future studies of feeding ecology and craniodental morphology in extant taxa.
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Affiliation(s)
- Erin R Vogel
- Department of Anthropology and Center for Human Evolutionary Studies, Rutgers, The State University of New Jersey, 131 George Street, Ruth Adams Building Suite 306, New Brunswick, NJ 08901-1414, USA.
| | - Astri Zulfa
- Universitas Nasional Jakarta, Jakarta, Indonesia
| | - Madeleine Hardus
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Serge A Wich
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
| | - Nathaniel J Dominy
- Department of Anthropology, 6047 Silsby Hall, Dartmouth College, Hanover, NH, USA
| | - Andrea B Taylor
- Department of Community and Family Medicine, Duke University School of Medicine, Box 104002, Durham, NC 27708, USA; Department of Evolutionary Anthropology, Duke University, 104 Biological Sciences Building, Box 90383, Durham, NC 27708-9976, USA
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Skinner MF. Variation in perikymata counts between repetitive episodes of linear enamel hypoplasia among orangutans from Sumatra and Borneo. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 154:125-39. [DOI: 10.1002/ajpa.22485] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 01/18/2014] [Indexed: 11/12/2022]
Affiliation(s)
- Mark F. Skinner
- Department of Archaeology; Simon Fraser University; Burnaby BC V5A 1S6 Canada
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Quantification of the dental morphology of orangutans. ScientificWorldJournal 2013; 2013:213757. [PMID: 24348143 PMCID: PMC3852088 DOI: 10.1155/2013/213757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 09/23/2013] [Indexed: 11/29/2022] Open
Abstract
Orangutans are believed to have close biological affinities to humans. Teeth being the hardest tissue provide useful information on primate evolution. Furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. A female Bornean orangutan and a Sumatran male orangutan skull were available for this study. Both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. Measurements included tooth and crown length, root length, enamel covered crown height, root canal length (posterior teeth), length of pulpal space (anterior teeth), and root canal width. Nonmetrical parameters included number of canals per root, number of foramina in each root, and root canal morphology according to Vertucci's classification. It was found that the enamel covered crown height was the longest in the upper central incisors although the canine was the longest amongst the anterior teeth. Both the upper premolars were three-rooted while the lower second premolar of the Sumatran orangutan was two-rooted, with two foramina. The mandibular lateral incisors of the Bornean orangutan were longer than the central incisors, a feature similar to humans. In addition, secondary dentine deposition was noticed, a feature consistent with aged humans.
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Ibrahim YK, Tshen LT, Westaway KE, Cranbrook EO, Humphrey L, Muhammad RF, Zhao JX, Peng LC. First discovery of Pleistocene orangutan (Pongo sp.) fossils in Peninsular Malaysia: Biogeographic and paleoenvironmental implications. J Hum Evol 2013; 65:770-97. [DOI: 10.1016/j.jhevol.2013.09.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 09/14/2013] [Accepted: 09/15/2013] [Indexed: 11/26/2022]
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Alba DM, Fortuny J, Pérez de los Ríos M, Zanolli C, Almécija S, Casanovas-Vilar I, Robles JM, Moyà-Solà S. New dental remains of Anoiapithecus and the first appearance datum of hominoids in the Iberian Peninsula. J Hum Evol 2013; 65:573-84. [DOI: 10.1016/j.jhevol.2013.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 07/02/2013] [Accepted: 07/02/2013] [Indexed: 10/26/2022]
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Wollny G, Kellman P, Ledesma-Carbayo MJ, Skinner MM, Hublin JJ, Hierl T. MIA - A free and open source software for gray scale medical image analysis. SOURCE CODE FOR BIOLOGY AND MEDICINE 2013; 8:20. [PMID: 24119305 PMCID: PMC4015836 DOI: 10.1186/1751-0473-8-20] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 08/07/2013] [Indexed: 11/12/2022]
Abstract
BACKGROUND Gray scale images make the bulk of data in bio-medical image analysis, and hence, the main focus of many image processing tasks lies in the processing of these monochrome images. With ever improving acquisition devices, spatial and temporal image resolution increases, and data sets become very large.Various image processing frameworks exists that make the development of new algorithms easy by using high level programming languages or visual programming. These frameworks are also accessable to researchers that have no background or little in software development because they take care of otherwise complex tasks. Specifically, the management of working memory is taken care of automatically, usually at the price of requiring more it. As a result, processing large data sets with these tools becomes increasingly difficult on work station class computers.One alternative to using these high level processing tools is the development of new algorithms in a languages like C++, that gives the developer full control over how memory is handled, but the resulting workflow for the prototyping of new algorithms is rather time intensive, and also not appropriate for a researcher with little or no knowledge in software development.Another alternative is in using command line tools that run image processing tasks, use the hard disk to store intermediate results, and provide automation by using shell scripts. Although not as convenient as, e.g. visual programming, this approach is still accessable to researchers without a background in computer science. However, only few tools exist that provide this kind of processing interface, they are usually quite task specific, and don't provide an clear approach when one wants to shape a new command line tool from a prototype shell script. RESULTS The proposed framework, MIA, provides a combination of command line tools, plug-ins, and libraries that make it possible to run image processing tasks interactively in a command shell and to prototype by using the according shell scripting language. Since the hard disk becomes the temporal storage memory management is usually a non-issue in the prototyping phase. By using string-based descriptions for filters, optimizers, and the likes, the transition from shell scripts to full fledged programs implemented in C++ is also made easy. In addition, its design based on atomic plug-ins and single tasks command line tools makes it easy to extend MIA, usually without the requirement to touch or recompile existing code. CONCLUSION In this article, we describe the general design of MIA, a general purpouse framework for gray scale image processing. We demonstrated the applicability of the software with example applications from three different research scenarios, namely motion compensation in myocardial perfusion imaging, the processing of high resolution image data that arises in virtual anthropology, and retrospective analysis of treatment outcome in orthognathic surgery. With MIA prototyping algorithms by using shell scripts that combine small, single-task command line tools is a viable alternative to the use of high level languages, an approach that is especially useful when large data sets need to be processed.
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Affiliation(s)
- Gert Wollny
- Biomedical Imaging Technologies, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain
- Ciber BBN, Zaragoza, Spain
| | - Peter Kellman
- Laboratory of Cardiac Energetics, National Heart, Lung and Blood Institute, National Institutes of Health, DHHS, Bethesda, MD, USA
| | - María-Jesus Ledesma-Carbayo
- Biomedical Imaging Technologies, ETSI Telecomunicación, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, Madrid 28040, Spain
- Ciber BBN, Zaragoza, Spain
| | - Matthew M Skinner
- Human Evolution, Max-Planck-Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, Germany
- UCL Anthropology, Gower Street, London, UK
| | - Jean-Jaques Hublin
- Human Evolution, Max-Planck-Institute for Evolutionary Anthropology, Deutscher Platz 6, Leipzig, Germany
| | - Thomas Hierl
- Department of Oral and Maxillo Facial Plastic Surgery, University of Leipzig Liebigstr. 10-14, Leipzig 4103, Germany
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