Tooth fractures in the Krapina Neandertals

American J Phys Anthropol

Loch

2021

Objectives A tooth chip occurs when a hard object forcefully contacts the surface of the tooth, typically removing enamel from the occlusal edge. In this study, chipping patterns in extant primates were compared, and hard‐object‐feeding assessed alongside other factors (e.g., grit mastication and dental properties), to elucidate dietary and behavioral inferences in archeological and paleontological samples. Materials and methods Thirteen species of extant primates were studied, including eight species within the Cercopithecidae, two within the Ceboidea, and three within the Hominoidea. Four additional species were also incorporated from the literature for some of the analyses. The severity (Grade 1–3), position (buccal, lingual, mesial, and distal) and number of tooth fractures were recorded for each specimen. Results Species considered hard‐object‐feeding specialists presented higher rates of chipping, with sakis, mandrills, sooty mangabeys and Raffles' banded langurs having high chipping rates (28.3%, 36.7%, 48.4%, and 34.7% of teeth, respectively). Species that seasonally eat harder foods had intermediate chipping frequencies (e.g., brown woolly monkeys: 18.5%), and those that less commonly consume hard food items had the lowest chipping frequencies (e.g., Kloss gibbon: 7.3%; chimpanzees: 4.4%). Discussion The results suggest hard food mastication influences differences in chipping prevalence among the species studied. Although Homo fossil samples show high rates of chipping comparable to hard‐object‐feeding extant primates, they display a different pattern of chipping, supporting the hypothesis that these fractures are mostly non‐food related (e.g., grit mastication in Homo naledi; non‐masticatory tooth use in Neanderthals).

Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Tooth chipping prevalence and patterns in extant primates

American J Phys Anthropol

Loch

2021

“…Data were compiled from the recent literature. Hominin samples include specimens assigned to H. naledi, A. africanus, P. robustus, P. boisei, H., neanderthalensis and H. sapiens (following Towle et al, 2017; Constantino et al, 2018; Constantino and Lawn, 2019; Bonfiglioli et al, 2004; Belcastro et al, 2018). Extant primates include chimpanzees ( Pan troglodytes troglodytes) , Western lowland gorillas ( Gorilla gorilla gorilla) , Kloss’s gibbons ( Hylobates klossii) , hamadryas baboons ( Papio hamadryas) , pig-tailed langurs ( Simias concolor) , Japanese macaques ( Macaca fuscata) , Dent’s mona monkey ( Cercopithecus denti) , blue monkeys ( Cercopithecus mitis) , mandrills ( Mandrillus leucophaeus and Mandrillus sphinx) , Raffles’ banded langurs ( Presbytis femoralis) , Mentawai langurs ( Presbytis potenziani) , brown woolly monkeys ( Lagothrix lagothricha) , Sakis ( Pithecia sp.…”

Section: Methodsmentioning

confidence: 99%

“…Smoothing and coloration were used for this purpose, i.e., postmortem fractures displaying ‘fresh’ enamel brighter than the rest of the crown and with sharp edges (Towle and Loch, 2021). The total number of chips on each tooth was also recorded for some samples (Belcastro et al, 2018; Towle et al, 2017; Towle and Loch, 2021). Results refer to all permanent teeth, unless stated otherwise.…”

Section: Methodsmentioning

confidence: 99%

Tooth chipping patterns inParanthropusdo not support regular hard food mastication

et al. 2021

Preprint

The paranthropines, including Paranthropus boisei and Paranthropus robustus, have often been considered hard-food specialists. The large post-canine teeth, thick enamel, and robust craniofacial features are often suggested to have evolved to cope with habitual mastication of hard foods. Yet, direct evidence for Paranthropus feeding behaviour often challenges these morphological interpretations. The main exception being antemortem tooth chipping which is still regularly used as evidence of habitual mastication of hard foods in this genus. In this study, data were compiled from the literature for six hominin species (including P. boisei and P. robustus) and 17 extant primate species, to analyse Paranthropus chipping patterns in a broad comparative framework. Severity of fractures, position on the dentition, and overall prevalence were compared among species. The results indicate that both Paranthropus species had a lower prevalence of tooth fractures compared to other fossil hominin species (P. boisei: 4%; P. robustus: 11%; Homo naledi: 37%; Australopithecus africanus: 17%; Homo neanderthalensis: 45%; Epipalaeolithic Homo sapiens: 29%); instead, their frequencies are similar to apes that masticate hard items in a non-regular frequency, including chimpanzees, gibbons, and gorillas (4%, 7% and 9% respectively). The prevalence is several times lower than in extant primates known to habitually consume hard items, such as sakis, mandrills, and sooty mangabeys (ranging from 28% to 48%). Comparative chipping analysis suggests that both Paranthropus species were unlikely habitual hard object eaters, at least compared to living durophage analogues.

Atypical tooth wear found in fossil hominins also present in a Japanese macaque population

American Journal of Biological Anthropology

MacIntosh

Hirata

et al. 2022

Objectives: Atypical tooth wear, including macroscopically visible striations on anterior teeth and within root grooves on posterior teeth, are often regarded as evidence of non-masticatory, tool use behavior in fossil hominins. Both these types of dental tissue loss are often considered unique to the genus Homo and suggested to be the earliest evidence of human cultural habits. The aim of this study was to describe similar tooth wear found in a wild primate population and to conduct a differential diagnosis of this atypical tissue loss. Materials and Methods:The focus of this study was a sample of wild Japanese macaques from Koshima Island, Japan. Individuals were provisioned regularly on the beach as part of one of the longest running primate field sites. Tooth wear and fractures in this group were compared to two other non-provisioned populations. Information on diet and behavior were obtained from extensive literature and on-going field observations. Results: All Koshima Island individuals analyzed showed atypical tooth wear. Large macroscopic striations were visible on many teeth, with sub-vertical striations prominent on the labial surfaces of incisors. Root grooves on posterior teeth were observed in half of the individuals, some showing clear directional striations similar to those reported in "toothpick" grooves in fossil hominins. Tool use and the habitual insertion of non-masticatory items in the mouth has not been observed in this population.Discussion: Accidental ingestion of sand and oral processing of marine mollusks likely creates these atypical wear patterns. Implications for similar wear that has been associated with tool-use in fossil hominin samples were discussed.