Testing dietary hypotheses of East African hominines using buccal dental microwear data

Abstract There is much debate on the dietary adaptations of the robust hominin lineages during the Pliocene-Pleistocene transition. It has been argued that the shift from C3 to C4 ecosystems in Africa was the main factor responsible for the robust dental and facial anatomical adaptations of Paranthropus taxa, which might be indicative of the consumption of fibrous, abrasive plant foods in open environments. However, occlusal dental microwear data fail to provide evidence of such dietary adaptations and are not consistent with isotopic evidence that supports greater C4 food intake for the robust clades than for the gracile australopithecines. We provide evidence from buccal dental microwear data that supports softer dietary habits than expected for P. aethiopicus and P. boisei based both on masticatory apomorphies and isotopic analyses. On one hand, striation densities on the buccal enamel surfaces of paranthropines teeth are low, resembling those of H. habilis and clearly differing from those observed on H. ergaster, which display higher scratch densities indicative of the consumption of a wide assortment of highly abrasive foodstuffs. Buccal dental microwear patterns are consistent with those previously described for occlusal enamel surfaces, suggesting that Paranthropus consumed much softer diets than previously presumed and thus calling into question a strict interpretation of isotopic evidence. On the other hand, the significantly high buccal scratch densities observed in the H. ergaster specimens are not consistent with a highly specialized, mostly carnivorous diet; instead, they support the consumption of a wide range of highly abrasive food items

Dental topography and dietary specialization in Papionini primates

Our understanding of primate adaptive evolution depends on appreciating the way in which dental functional morphology affects food processing. The Papionini tribe of Cercopithecoidea primates shows great dietary versatility and ecological adaptations to resource seasonality across the African and Asian ecosystems, however, there are few studies focusing on the occlusal topography of the bilophodont teeth and the effect of tooth wear in the crown shape. Here, we explore the relationship between wear-related dental functional morphology and dietary ecological constraints within the Papionini. Three-dimensional (3D) polygonal meshes of the upper permanent molar row (M1-3) were obtained in a large papionine sample (838 specimens) of known dietary preferences including species from six genera (Cercocebus, Lophocebus, Macaca, Mandrillus, Papio, and Theropithecus). All the sample was classified in four diet categories and four topographic metrics (orientation patch count rotated, OPCR; Dirichlet normal energy, DNE; occlusal relief, OR; and ambient occlusion, portion de ciel visible, PCV) were measured for each tooth-type according to wear stage (lightly and moderately worn) to determine diet-related interspecific morphological changes with long-term functionality. The results indicate that hard-object feeders (Cercocebus and Lophocebus) and grass eaters (Theropithecus gelada) exhibit a pattern of occlusal complexity (OPCR), surface curvature (DNE), relief (OR), and morphological wear resistance (PCV) that is significantly different from the omnivores and folivore-frugivore species (Mandrillus and Macaca) despite the overall homogeneity of the bilophodont dentition. A multifactorial ANOVA showed that the topographic metrics were sensitive to tooth wear as expected. The results also indicate that the interspecific variability of dental topography of the upper molars reflects dietary specializations rather than phylogenetic proximity. These findings support the hypothesis that evolutionary convergence processes could have affected the Papionini, clustering the hard-object feeders (Lophocebus and Cercocebus) together in the morphospace, and clearly discriminating this group from the graminivorous and frugivores-folivores.Grants PID2020-112963GB-I00 to APP and PID2020-114517GB-I00 to AR, funded by MCIN/AEI/ 10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union”. www.paleobaboonproject.science

Nota metodológica: Alteración del patrón de microestriación dentaria por el efecto wrinkle.

Se describe el efecto wrinkle observado por primera vez sobre moldes dentarios realizados con resinas epoxy y metalizados en oro para su observación mediante microscopía electrónica de barrido (SEM). Con el fin de determinar en qué medida puede afectar al análisis del patrón de microestriación vestibular, se analizan dos muestras dentales de tres especies de Hominoideos, una de ellas incluyendo moldes con presencia de"aguas" relacionadas con el proceso de metalización. Se observa un descenso marcado de la variabilidad del patrón de microestriación dentaria anque las diferencias entre las dos muestras por especie no son estadísticamente significativas. El efecto wrinkle reduce significativamente el porcentaje de clasificación correcta de las especies analizadas a partir del patrón de microestriación y rugosidad dental utilizando un Análisis Discriminante. Se aconseja evitar la inclusión de las muestras afectadas por aguas en los estudios del patrón de microestriación dentaria

The diet of the first Europeans from Atapuerca

Hominin dietary specialization is crucial to understanding the evolutionary changes of craniofacial biomechanics and the interaction of food processing methods’ effects on teeth. However, the diet-related dental wear processes of the earliest European hominins remain unknown because most of the academic attention has focused on Neandertals. Non-occlusal dental microwear provides direct evidence of the effect of chewed food particles on tooth enamel surfaces and reflects dietary signals over time. Here, we report for the first time the direct effect of dietary abrasiveness as evidenced by the buccal microwear patterns on the teeth of the Sima del Elefante-TE9 and Gran Dolina-TD6 Atapuerca hominins (1.2–0.8 million years ago − Myr) as compared with other Lower and Middle Pleistocene populations. A unique buccal microwear pattern that is found in Homo antecessor (0.96–0.8 Myr), a well-known cannibal species, indicates dietary practices that are consistent with the consumption of hard and brittle foods. Our findings confirm that the oldest European inhabitants ingested more mechanically-demanding diets than later populations because they were confronted with harsh, fluctuating environmental conditions. Furthermore, the influence of grit-laden food suggests that a high-quality meat diet from butchering processes could have fueled evolutionary changes in brain size.This work was supported by the research grants, from the Dirección General de Investigación of Ministerio Ciencia y Tecnología (Spain), numbers CGL2007-60802/BTE, CGL2011-22999, CGL2012-38434-C03-01/02/03 and CGL2014-52611-C2-1-P, as well as by the grant 2009SGR884 Group of Study on the Evolution of Hominins and other Primates and grant 2014SGR900 Group of Analyses on Socio-Ecological Processes, Cultural Changes and Population Dynamics during Prehistory (GAPS) and CERCA Programme of the Generalitat de Catalunya

The diet of the first Europeans from Atapuerca

Hominin dietary specialization is crucial to understanding the evolutionary changes of craniofacial biomechanics and the interaction of food processing methods' effects on teeth. However, the diet-related dental wear processes of the earliest European hominins remain unknown because most of the academic attention has focused on Neandertals. Non-occlusal dental microwear provides direct evidence of the effect of chewed food particles on tooth enamel surfaces and reflects dietary signals over time. Here, we report for the first time the direct effect of dietary abrasiveness as evidenced by the buccal microwear patterns on the teeth of the Sima del Elefante-TE9 and Gran Dolina-TD6 Atapuerca hominins (1.2-0.8 million years ago − Myr) as compared with other Lower and Middle Pleistocene populations. A unique buccal microwear pattern that is found in Homo antecessor (0.96-0.8 Myr), a well-known cannibal species, indicates dietary practices that are consistent with the consumption of hard and brittle foods. Our findings confirm that the oldest European inhabitants ingested more mechanically-demanding diets than later populations because they were confronted with harsh, fluctuating environmental conditions. Furthermore, the influence of grit-laden food suggests that a high-quality meat diet from butchering processes could have fueled evolutionary changes in brain size

Multiproxy approach to reconstruct fossil primate feeding behavior: Case study for macaque from the Plio-Pleistocene site Guefaït-4.2 (eastern Morocco)

The genus Macaca belongs to Cercopithecidae (Old World monkeys), Cercopithecinae, Papionini. The presence of Macaca in North Africa is well known from the Late Miocene to the Late Pleistocene. However, the diet of fossil Macaca has been poorly described in the literature. In this study, we investigated the feeding habits of Macaca cf. sylvanus (n = 4) from the Plio-Pleistocene site Guefaït-4.2 in eastern Morocco through multiproxy analysis combining analyses of stable carbon and oxygen isotopes from tooth enamel, buccal microtexture, and low-magnification occlusal dental microwear. For both microwear analyses, we compared the macaques with a new reference collection of extant members of Cercopithecoidea. Our occlusal microwear results show for the fossil macaque a pattern similar to the extant Cercocebus atys and Lophocebus albigena, African forest-dwelling species that are characterized by a durophagous diet based mainly on hard fruit and seed intake. Buccal microtexture results also suggest the consumption of some grasses and the exploitation of more open habitats, similar to that observed in Theropithecus gelada. The δ13C of M. cf. sylvanus indicates a C3 based-diet without the presence of C4 plants typical of the savanna grassland in eastern Africa during this period. The high δ18O values of M. cf. sylvanus, compared with the contemporary ungulates recovered from Guefaït-4.2, could be associated with the consumption of a different resource by the primate such as leaves or fresh fruits from the upper part of trees. The complementarity of these methods allows for a dietary reconstruction covering a large part of the individual’s life.This work has been funded by Palarq Foundation, Spanish Ministry of Culture and Sport (Ref: 42-T002018N0000042853 and 170-T002019N0000038589), Direction of Cultural Heritage (Ministry of Culture and Communication, Morocco), Faculty of Sciences (Mohamed 1r University of Oujda, Morocco), INSAP (Institut National des Sciences de l’Archéologie et du Patrimoine), Spanish Ministry of Science, Innovation and Universities (Ref: CGL2016-80975-P, CGL2016-80000-P, PGC2018-095489-B-I00, and PID2021- 122355NB-C33), Research Groups Support of the Generalitat de Catalunya (2017 SGR 836, 2017 SGR 1040, 2017 SGR 102, and 2017 SGR 859) and PDC2021-121613-I00 and PID2020-112963GB-I00 by ERDF A way of making Europe, by the European Union. RS-R, MC, AR-H, and CT research was funded by CERCA Programme Generalitat de Catalunya. IR-P is beneficiary of predoctoral fellowship (2020-FI-B-00731) funded by AGAUR and the Fons Social Europeu (FSE). AA and is beneficiary of a fellowship from the Erasmus Mundus Program to do the Master in Quaternary and Prehistory at the Universitat Rovira i Virgili (Tarragona, Spain). CT was supported by the Spanish Ministry of Science and Innovation through the “Ramón y Cajal” program (RYC2020-029404-I). The Institut Català de Paleoecologia Humana i Evolució Social (IPHES-CERCA) has received financial support from the Spanish Ministry of Science and Innovation through the “María de Maeztu” program for Units of Excellence (CEX2019-000945-M), including the postdoctoral fellowships of AR-H.With funding from the Spanish government through the "Severo Ochoa Center of Excellence" accreditation CEX2019-000945-M.Peer reviewe

Aboriginal fire use: from responsible for Australia’s environmental change to a successful tool for the management of natural fires

[EN] The acquisition of fire is one of the key aspects of the process of hominization that made possible the expansion of the ecological niche in the early hominins. Although there is no consensus on the precise timing that hominins acquired the control of fire, there is no doubt that it allowed the gradual transformation of landscapes. During Late Pleistocene, a global extinction event of the megafauna is reported in several regions of the Earth, including Australia. This process was synchronous with the arrival of Homo sapiens in North America and Australia, the reason for which it has been hypothesized that human influence would have been determinant in the disappearance of the megafauna. In the specific case of Australia, the particular use of fire by Aboriginals, called fire-stick farming, which provides a mechanism to increase productivity by selectively burning patches of mature vegetation, would be the trigging factor that unleashed megafaunal extinction. However, it is not clear that fire-stick farming was so determinant and some authors advocate for a climate-driven process. Be that as it may, traditional Australian burning practice has now become a useful tool for wildfire control and a mechanism to increase biodiversity in Australian landscapes.[ES] La adquisición del fuego es uno de los aspectos clave del proceso de hominización que hizo posible la expansión del nicho ecológico en los primeros homininos. Aunque no hay consenso sobre el momento preciso en que los homininos adquirieron el control del fuego, no hay duda de que permitió la transformación gradual de los paisajes. Durante el Pleistoceno tardío, se produjo un evento de extinción global de la megafauna en varias regiones de la Tierra, incluida Australia. Este proceso fue sincrónico con la llegada del Homo sapiens a Norteamérica y Australia, por lo que se ha planteado la hipótesis de que la influencia humana habría sido determinante en la desaparición de la megafauna. En el caso concreto de Australia, el particular uso del fuego por parte de los aborígenes, denominado “fire-stick farming”, que proporciona un mecanismo para aumentar la productividad mediante la quema selectiva de parches de vegetación madura, sería el factor desencadenante que desencadenaría la extinción de la megafauna. Sin embargo, no está claro que el “fire-stick farming” fuera tan determinante, y algunos autores abogan por un proceso impulsado por el clima. Sea como fuere, la práctica tradicional australiana de quemas se ha convertido ahora en una herramienta útil para el control de incendios forestales y un mecanismo para aumentar la biodiversidad en los paisajes australianos

Diet in the Early Bronze Age: a buccal microwear analysis from the plain of Barcelona (Spain)

This study aims to characterize the dietary habits of the Barcelona plain (Spain) population during the Early Bronze Age. An analysis of buccal microwear has been performed on 467 samples from 20 individuals buried in the largest cemetery of the plain of Barcelona in this period, the Plaça de la Gardunya, and 1 sample from the site of the Mercat de Santa Caterina. Molars and premolars were examined using a scanning electron microscope (SEM), and their microwear patterns were compared with reference patterns associated with known dietary habits and subsistence strategies. The results suggest that dietary habits differed between age groups and between sexes: males were more carnivorous than females, and subadults ate harder foods than adults. Buccal microwear from the Barcelona plain shows similar values to carnivorous diets of anthropological populations. Based on all the archaeological evidence (building types and zooarchaeology, archaeobotany and stone tools) from this settlement and those in its vicinity, we propose that the individuals from the Barcelona plain had a mixed diet, with large consumption of meat, secondary products and fish. Agricultural products, stored in silos and grill structures and processed with more sophisticated grinding techniques, were also consumed, mainly by subadult individuals.This research has been funded by the project Prehistòria al pla de Barcelona, cooperated by the ICUB Servei d’Arqueologia, the Museu d’Història de Barcelona and the Prehistory Department of the Autonomous University of Barcelona. This study has also been supported by the Spanish Ministerio de Ciencia e Innovacion (project numberd PID2019-106399GB-I00) and funded by PID2020-112963GB-I00 by MNCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” by the “European Union”) and finally the GRAMPO research group (2017SGR-1302). Alicia Gluitz has been granted with a FPU research scholarship from the Spanish Ministerio de Universidades (FPU20/03612), a support that has enabled the successful completion of this study

Correlations among dietary proxies in African fossil hominins: Dental buccal microwear, occlusal textures and 13C stable isotope

Dietary proxies for inferring diet composition of African hominin species have been widely used. However, results derived from buccal microwear patters, occlusal textural data and carbon stable isotope are not always concordant. We have analyzed the correlations between the different variables measured with each methodological approach at two distinct levels. We first, computed paired correlation among fossil specimens for whom dietary data was available and then analyzed the trends in dietary proxies variables among the fossil hominin species considered. The results show some significant correlations between variables. However, some inconsistencies among the different methodologies are evident, especially between buccal and occlusal microwear proxies and between the microwear patterns and δ13C signals. Differences in age ranges and life span for applying the different techniques might explain the inconsistencies observed. Further data on dental microwear patterns are required for further a more informative investigation on the associations between the dietary proxies.The Spanish Ministry of Science and Innovation [CGL2014-52611-C2-1-P] supported this research