Endocasts of ornithopod dinosaurs: Comparative anatomy.

Ornithopod dinosaurs were a successful group before they became extinct at the end of the Cretaceous. They were present on every continent, though they were rare in the Southern Hemisphere. We present the results of our work on the brain of these dinosaurs as an attempt to determine which evolutionary trends affected it. Old and new technologies allow us to peer into the skull of long extinct animals and retrieve information about their brain. First we provide a short description of the brain of ornithopod dinosaurs from Europe and Asia, then we sum up the characteristics that can be gathered from it. The presence of valleculae helps us to assess the actual size of the brain with more confidence. The olfactory peduncles are large and these animals had a good sense of smell. There is a trend toward an increase in the size of the cerebral hemispheres, and a more straight-lined brain. The latter can be the result of the ontogeny and the size achieved by the adult animal on the development of the brain. Other characteristics, like the development of the cerebral hemispheres and the encephalization quotient, allude to Hadrosauridae having had cognitive abilities more developed than previously assumed. This is in adequacy with other data from the physical characteristics (e.g., crests) and the social life (e.g., living in herds, communal nests) of these dinosaurs, which denote high and complex behaviors like care for their young, sexual courtship, and gregariousness.

The burning maze: The potential value of the human bony labyrinth in estimating sex of calcined remains.

Estimating sex from burnt human remains is a challenging task in bioanthropology, mainly due to their high level of alteration and fragmentation. Protected within the petrous part of the temporal bone, the bony labyrinth may be particularly valuable for assessing the sex of burnt remains. This prospective study aims at testing predictive models, already found reliable on unburnt bony labyrinths, to burnt specimens. Six discriminant functions were applied on six bony labyrinths of donated adult cadavers of known sex, before and after outdoor burning experiments. Comparisons between unburnt and burnt measurements were executed using Mann-Whitney U tests while shape and size differences induced by fire exposure were examined through a geometric morphometrics (GM) analysis. Predicted sex on unburnt bony labyrinths was consistent with known sex in five cases while a systematic misclassification for males was highlighted on burnt specimens. Higher values of shrinkage were found in males for two measurements included in the equations. GM analysis revealed significant differences in centroid size among males after calcination. Visualization of mean consensus of both female and male bony labyrinths evidenced a reduction in cochlear size and variations in the width and length of semicircular canals of burnt specimens. This exploratory study seems to confirm that designing sex estimation standards specifically for burnt bony labyrinth may be advisable. Understanding how the burning process could impact its morphology is highly recommended through further experiments on larger samples and in controlled environments.

Strontium isotopes and concentrations in cremated bones suggest an increased salt consumption in Gallo-Roman diet.

The high temperatures reached during cremation lead to the destruction of organic matter preventing the use of traditional isotopic methods for dietary reconstructions. Still, strontium isotope (87Sr/86Sr) and concentration ([Sr]) analyses of cremated human remains offer a novel way to assess changing consumption patterns in past populations that practiced cremation, as evidenced by a large amount of new data obtained from Metal Ages and Gallo-Roman human remains from Destelbergen, Belgium. The Gallo-Roman results show significantly higher [Sr] and a narrower interquartile range in 87Sr/86Sr (0.7093-0.7095), close to the value of modern-day seawater (0.7092). This contrasts with the Metal Ages results, which display lower concentrations and a wider range in 87Sr/86Sr (0.7094-0.7098). This typical Sr signature is also reflected in other sites and is most likely related to an introduction of marine Sr in the form of salt as a food preservative (e.g. salt-rich preserved meat, fish and fish sauce). Paradoxically, this study highlights caution is needed when using 87Sr/86Sr for palaeomobility studies in populations with high salt consumption.

Automated age-at-death estimation by cementochronology: Essential application or additional complication?

It has been repeatedly acknowledged that age-at-death estimation based on dental cementum represents a partial and time-consuming method that hinders adoption of this histological approach. User-friendly micrograph analysis represents a growing request of cementochronology. This article evaluates the feasibility of using a module to accurately quantify cementum deposits and compares the module's performance to that of a human expert. On a dental collection (n = 200) of known-age individuals, precision and accuracy of estimates performed by a developed program (101 count/tooth; n = 20,200 counts) were compared to counts performed manually (5 counts/tooth; n = 975 counts). Reliability of the software and agreement between the two approaches were assessed by intraclass correlation coefficient and Bland Altman analysis. The automated module produced reliable and reproducible counts with a higher global precision than the human expert. Although the software is slightly more precise, it shows higher sensitivity to taphonomic damages and does not avoid the trajectory effect described for age-at-death estimation in adults. Likewise, for human counts, global accuracy is acceptable, but underestimations increase with age. The quantification of the agreement between the two approaches shows a minor bias, and 94% of individuals fall within the intervals of agreement. Automation gives an impression of objectivity even though the region of interest, profile position and parameters are defined manually. The automated system may represent a time-saving module that can allow an increase in sample size, which is particularly stimulating for population-based studies.

These boots are made for burnin': Inferring the position of the corpse and the presence of leather footwears during cremation through isotope (δ13C, δ18O) and infrared (FTIR) analyses of experimentally burnt skeletal remains.

Cremation is a complex mortuary practice, involving a number of activities of the living towards the dead before, during, and after the destruction of the bodily soft tissues by fire. The limiting information concerning these behavioral patterns obtained from the pyre remains and/or cremation deposits prevents the reconstruction of the handling of the corpse during the burning process. This pioneering study tries to determine the initial positioning of the corpse in the pyre and assess whether the deceased was wearing closed leather shoes during cremation through isotopic (δ13C, δ18O) and infrared (ATR-FTIR) analyses of experimentally burnt pig remains, used as a proxy for humans. The results obtained show that both the position of feet on or within the pyre and the presence of footwears may moderately-to-highly influence the oxygen isotope ratios of bone apatite carbonates and the cyanamide content of calcined bone in certain situations. By forming a protective layer, shoes appear to temporarily delay the burning of the underlying pig tissues and to increase the heat-shielding effect of the soft tissues protecting the bone mineral fraction. In such case, bioapatite bone carbonates exchange oxygen with a relatively more 18O-depleted atmosphere (due to the influence of lignin-derived oxygen rather than cellulose-derived oxygen), resulting in more pronounced decrease in the δ18Ocarb values during burning of the shoed feet vs. unshoed feet. The shift observed here was as high as 2.5‰. A concomitant isotopic effect of the initial location of the feet in the pyres was also observed, resulting in a top-to-bottom decrease difference in the δ18Ocarb values of shoed feet of about 1.4‰ between each deposition level tested. Finally, the presence of cyanamide (CN/P ≥ 0.02) seems to be indicative of closed footwear since the latter creates favorable conditions for its incorporation into bone apatite.

Revisiting metric sex estimation of burnt human remains via supervised learning using a reference collection of modern identified cremated individuals (Knoxville, USA).

OBJECTIVES: This study aims to increase the rate of correctly sexed calcined individuals from archaeological and forensic contexts. This is achieved by evaluating sexual dimorphism of commonly used and new skeletal elements via uni- and multi-variate metric trait analyses. MATERIALS AND METHODS: Twenty-two skeletal traits were evaluated in 86 individuals from the William M. Bass donated cremated collection of known sex and age-at-death. Four different predictive models, logistic regression, random forest, neural network, and calculation of population specific cut-off points, were used to determine the classification accuracy (CA) of each feature and several combinations thereof. RESULTS: An overall CA of ≥ 80% was obtained for 12 out of 22 features (humerus trochlea max., and lunate length, humerus head vertical diameter, humerus head transverse diameter, radius head max., femur head vertical diameter, patella width, patella thickness, and talus trochlea length) using univariate analysis. Multivariate analysis showed an increase of CA (≥ 95%) for certain combinations and models (e.g., humerus trochlea max. and patella thickness). Our study shows metric sexual dimorphism to be well preserved in calcined human remains, despite the changes that occur during burning. CONCLUSIONS: Our study demonstrated the potential of machine learning approaches, such as neural networks, for multivariate analyses. Using these statistical methods improves the rate of correct sex estimations in calcined human remains and can be applied to highly fragmented unburnt individuals from both archaeological and forensic contexts.

Sexing the bony labyrinth: A morphometric investigation in a subadult and adult Belgian identified sample.

In forensic anthropology, sex estimation is a fundamental step in assessing individual biological profiles when analyzing human skeletons. Yet, current methods are not reliable enough to allow an accurate sex identification of highly fragmented, burnt, or subadult remains. This paper aims to investigate sexual dimorphism of the bony labyrinth on both identified subadult and adult individuals. The bony labyrinth is of particular interest for sex estimation since it is alleged to complete size and maturation pre-pubertally and is located inside the petrous part of the temporal bone which protects it from taphonomic processes. The study was performed on 93 CT scans of identified individuals from two Belgian osteological collections (19-20th century) and from current pediatric images (Erasme hospital, Brussels). Linear and angular measurements were taken on 2D slices of right bony labyrinths. Intra- and interobservers error measurements were calculated. Statistical tests were used to unravel any morphological variations between subadult and adult bony labyrinths and to highlight differences between females and males, separately in subadults and adults. Linear discriminant functions were established by cross-validation and tested on an independent sample from Belgium. Some measurements were significantly different between subadults and adults, and between females and males within both subadult and adult samples. Univariate functions achieved 72.7% in subadults and 68.4% in adults whereas multivariate equations increased accuracy respectively up to 84.9% and 78.4%. This study entails promising results to design a sex estimation method suitable for fragmented and/or subadult remains. Further metric approaches are needed to explore bony labyrinth sexual dimorphism.

Estimating age-at-death in burnt adult human remains using the Falys-Prangle method.

OBJECTIVES: The Falys-Prangle-method assesses age-related morphological changes to the sternal clavicle end (SCE), enabling the observation of mature adults from the 5th decade onwards in unburnt human skeletal remains. The aim of this study is to investigate the applicability of the Falys-Prangle-method on burnt human remains. MATERIALS AND METHODS: Fifty-two SCE of 40 cremated individuals (out of 86) from the William M. Bass collection of the Forensic Anthropology Center (Knoxville, Tennessee) of known age-at-death and sex are available for assessment. Surface topography, porosity, and osteophyte formation are evaluated, after which the calculated composite score is associated with the corresponding age range as described by Falys and Prangle. The method is also applied on an archaeological case study from Oudenburg, Belgium, dating to the Roman period. RESULTS: The assessed age ranges strongly agree with the true age ranges (α = 0.828), suggesting the Falys-Prangle-method to be applicable on burnt human remains. The case study from Oudenburg yields markedly improved age-at-death estimates, significantly enhancing our understanding of the age distribution within this community. DISCUSSION: Information on age-at-death is key in the construction of biological profiles of past individuals. The mature adult is often invisible in the archaeological record since most macroscopic age estimation methods do not distinguish beyond 46+ years old. Our study stresses the usefulness of a large-scale application of the Falys-Prangle-method, which will increase the visibility of mature adults, especially in archaeological burnt human skeletal collections, where such information is, at present, extremely difficult to obtain.

Referencias de peso, estatura e índice de masa corporal para niñas y niños ecuatorianos de 5 a 19 años de edad / Growth references for weight, height, and body mass index for Ecuadorian children and adolescents aged 5-19 years

Introducción. La evaluación del crecimiento durante la infancia y la adolescencia es un componente fundamental de la atención de salud en todos sus niveles, pues es parte del diagnóstico nutricional y permite la detección oportuna de patologías relacionadas. Ecuador, al no disponer de referencias nacionales de crecimiento, ha adoptado los estándares internacionales de la Organización Mundial de la Salud. El objetivo de este estudio fue construir referencias nacionales de peso, estatura e índice de masa corporal para niños, niñas y adolescentes.Métodos. Se investigaron escolares y adolescentes ecuatorianos entre 5 y 19 años de edad durante 1999 y 2012. Los centilos 3, 10, 25, 50, 75, 90 y 97 de peso, talla e índice de masa corporal fueron estimados por el método LMS para datos transversales, que utiliza la transformación Box-Cox para normalizar la distribución de los datos a cada edad.Resultados. Participaron 5934 sujetos sanos (2788 niños y 3146 niñas). Los niños pesaban más y eran más altos que las niñas. En todos los casos, los valores mostraron un aumento creciente conforme la edad avanzaba. A los 18 años, las diferencias entre sexos promediaron 8 kg y 12,5 cm.Conclusión. Las tablas y curvas producto de este estudio constituyen la primera referencia descriptiva del crecimiento de niños ecuatorianos de 5-19 años. Son un importante instrumento de evaluación nutricional. Su implementación en la atención primaria de salud permitirá complementar el diagnóstico nutricional que, tradicionalmente, se realiza sobre la base de los estándares internacionales de la Organización Mundial de la Salud.

Introduction. The assessment of growth during childhood and adolescence is a critical component of health care at all levels, but it is also part of nutritional status diagnosis and the timely detection of related conditions. Ecuador lacks national growth references, so it has decided to adopt the international standards proposed by the World Health Organization. The objective of this study was to develop national references for weight, height, and body mass index for children and adolescents.Methods. Ecuadorian schoolchildren and adolescents aged 5-19 years were studied between 1999 and 2012. The LMS method for cross-sectional data, which uses the Box-Cox transformation to normalize data distribution at each age, was applied to estimate the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th centiles for weight, height, and body mass index.Results. A total of 5934 healthy subjects (2788 boys and 3146 girls) participated. Boys were heavier and taller than girls. In all cases, values increased with age. At 18 years old, the differences between sexes averaged 8 kg and 12.5 cm.Conclusion. The tables and curves obtained with this study are the first descriptive growth references for Ecuadorian children and adolescents aged 5-19 years. They are relevant for nutritional assessment. Their use at the primary level of care will aid in nutritional status diagnosis, which has traditionally been done based on the World Health Organization's international standards.

Growth references for weight, height, and body mass index for Ecuadorian children and adolescents aged 5-19 years. / Referencias de peso, estatura e índice de masa corporal para niñas y niños ecuatorianos de 5 a 19 años de edad.

INTRODUCTION: The assessment of growth during childhood and adolescence is a critical component of health care at all levels, but it is also part of nutritional status diagnosis and the timely detection of related conditions. Ecuador lacks national growth references, so it has decided to adopt the international standards proposed by the World Health Organization. The objective of this study was to develop national references for weight, height, and body mass index for children and adolescents. METHODS: Ecuadorian schoolchildren and adolescents aged 5-19 years were studied between 1999 and 2012. The LMS method for cross-sectional data, which uses the Box-Cox transformation to normalize data distribution at each age, was applied to estimate the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th centiles for weight, height, and body mass index. RESULTS: A total of 5934 healthy subjects (2788 boys and 3146 girls) participated. Boys were heavier and taller than girls. In all cases, values increased with age. At 18 years old, the differences between sexes averaged 8 kg and 12.5 cm. CONCLUSION: The tables and curves obtained with this study are the first descriptive growth references for Ecuadorian children and adolescents aged 5-19 years. They are relevant for nutritional assessment. Their use at the primary level of care will aid in nutritional status diagnosis, which has traditionally been done based on the World Health Organization's international standards.

Introducción. La evaluación del crecimiento durante la infancia y la adolescencia es un componente fundamental de la atención de salud en todos sus niveles, pues es parte del diagnóstico nutricional y permite la detección oportuna de patologías relacionadas. Ecuador, al no disponer de referencias nacionales de crecimiento, ha adoptado los estándares internacionales de la Organización Mundial de la Salud. El objetivo de este estudio fue construir referencias nacionales de peso, estatura e índice de masa corporal para niños, niñas y adolescentes. Métodos. Se investigaron escolares y adolescentes ecuatorianos entre 5 y 19 años de edad durante 1999 y 2012. Los centilos 3, 10, 25, 50, 75, 90 y 97 de peso, talla e índice de masa corporal fueron estimados por el método LMS para datos transversales, que utiliza la transformación Box- Cox para normalizar la distribución de los datos a cada edad. Resultados. Participaron 5934 sujetos sanos (2788 niños y 3146 niñas). Los niños pesaban más y eran más altos que las niñas. En todos los casos, los valores mostraron un aumento creciente conforme la edad avanzaba. A los 18 años, las diferencias entre sexos promediaron 8 kg y 12,5 cm. Conclusión. Las tablas y curvas producto de este estudio constituyen la primera referencia descriptiva del crecimiento de niños ecuatorianos de 5-19 años. Son un importante instrumento de evaluación nutricional. Su implementación en la atención primaria de salud permitirá complementar el diagnóstico nutricional que, tradicionalmente, se realiza sobre la base de los estándares internacionales de la Organización Mundial de la Salud.

Geophagy in the yellow-tailed woolly monkey (Lagothrix flavicauda) at La Esperanza, Peru: site characterization and soil composition.

Geophagy is the intentional consumption of soil and has been observed in various animal taxa including human and nonhuman primates. Among the numerous adaptive hypotheses proposed to explain this behavior, two of them stand out: soil either protects the gastrointestinal tract from secondary plant compounds, parasites and pathogens, and/or supplements micronutrients in the diet. Few studies have characterized the physical and chemical characteristics of soils consumed by nonhuman primates. Here, we describe the composition of soils consumed by yellow-tailed woolly monkeys (Lagothrix flavicauda) in comparison with soils taken from surrounding areas. We also studied the physical aspects of geophagy sites in terms of accessibility, dimensions and vegetation density. This study took place at the La Esperanza field site, in northern Peru, between 2016 and 2018. We conducted focal follows, placed camera traps at geophagy sites and sampled soils. In total, we recorded 77 geophagy events. Our results highlight some aspects of soil and site selection in these arboreal primates, who face an increased predation risk when descending to the ground. Animals preferred smaller sites with denser surrounding vegetation. Composition of consumed soils was similar between geophagy sites. Soils were poor in micronutrients, but contained around 20% clay. High clay content, coupled with the fact that geophagy was performed significantly more in the dry season, when leaf consumption is highest, lends support to geophagy as a mechanism for protection of the gastrointestinal tract in L. flavicauda.

Seed dispersal by proboscis monkeys: the case of Nauclea spp.

Frugivorous vertebrates such as primates are important dispersal agents in tropical forests, although the role of folivorous colobines is generally not considered. However, recent studies reported seed dispersal by endo- and epizoochory in colobine primates, including the proboscis monkey (Nasalis larvatus), suggesting that the role colobines play in seed dispersal might have been underestimated. In the Lower Kinabatangan Floodplain in Sabah, Malaysian Borneo, we investigated whether seeds were still able to germinate after being ingested by proboscis monkeys. Faecal samples (n = 201) from proboscis monkeys were collected between 2015 and 2017. Intact seeds belonging to eight plant species were found in 77% of the faecal samples. Nauclea spp. were the most abundant plant species, accounting for 98% of all intact seeds. This study is the first to conduct germination trials on seeds defecated by proboscis monkeys. Higher germination success was recorded in ingested Nauclea spp. seeds than in control seeds, from both ripe and unripe Nauclea orientalis fruits (P < 0.001). Therefore, we suggest that proboscis monkeys play a role in seed dispersal by enhancing the germination success of defecated seeds for at least some plant species. Similar to other colobines, although proboscis monkeys may provide a lower contribution to seed dispersal (low seed diversity over short distances) than other sympatric frugivores, this study emphasises that proboscis monkeys do contribute to the dispersal of intact seeds, such as Nauclea spp., in potentially suitable riverine habitats.

Faecal Particle Size in Free-Ranging Proboscis Monkeys, Nasalis larvatus: Variation between Seasons.

Reducing the size of food particles is crucial for herbivores. Seasonal dietary changes are known to influence animals' chewing efficiency. Proboscis monkeys (Nasalis larvatus) are foregut fermenters, with a high chewing efficiency allowing them to achieve very fine faecal particles. In this study, we investigated how proboscis monkeys' chewing efficiency varies between wet and dry seasons, hypothesising differences possibly related to diet change. Faecal particle size analysis is an established approach to estimate chewing efficiency in mammalian herbivores. We analysed 113 proboscis monkey faecal samples collected in the Lower Kinabatangan Wildlife Sanctuary, between 2015 and 2017. By following standard sieve analysis protocols, we measured a mean particle size MPS0.025-8 of 0.45 ± 0.14 mm, and confirmed a previous result that proboscis monkeys have a very low faecal MPS. This study highlights a seasonal influence on proboscis monkeys' chewing efficiency, with smaller MPS (better chewing efficiency) during the wet season. During that time of the year, individuals may potentially change their diet, as all faecal samples contained intact seeds. Whether the seasonal MPS difference in proboscis monkeys is smaller than in other colobines due to their "rumination" strategy remains to be investigated.

Use and Selection of Sleeping Sites by Proboscis Monkeys, Nasalislarvatus, along the Kinabatangan River, Sabah, Malaysia.

The choice of a sleeping site is crucial for primates and may influence their survival. In this study, we investigated several tree characteristics influencing the sleeping site selection by proboscis monkeys (Nasalis larvatus) along Kinabatangan River, in Sabah, Malaysia. We identified 81 sleeping trees used by one-male and all-male social groups from November 2011 to January 2012. We recorded 15 variables for each tree. Within sleeping sites, sleeping trees were taller, had a larger trunk, with larger and higher first branches than surrounding trees. The crown contained more mature leaves, ripe and unripe fruits but had vines less often than surrounding trees. In addition, in this study, we also focused on a larger scale, considering sleeping and non-sleeping sites. Multivariate analyses highlighted a combination of 6 variables that revealed the significance of sleeping trees as well as surrounding trees in the selection process. During our boat surveys, we observed that adult females and young individuals stayed higher in the canopy than adult males. This pattern may be driven by their increased vulnerability to predation. Finally, we suggest that the selection of particular sleeping tree features (i.e. tall, high first branch) by proboscis monkeys is mostly influenced by antipredation strategies.

Cranial Endocast of the lambeosaurine hadrosaurid Amurosaurus riabinini from the Amur region, Russia.

Information on the structure of the brain of the lambeosaurine hadrosaurid dinosaur Amurosaurus riabinini, from the Late Maastrichtian of Blagoveschensk, Far Eastern Russia, is presented based on endocranial casts. The endocasts are compared with physical and digital endocasts of other dinosaurs. The olfactory tract was large. The cerebral hemispheres are enlarged and round, illustrating the important development of this part of the brain in hadrosaurids. The pituitary body is enlarged as well, perhaps prefiguring the large size attained by hadrosaurids. The EQ of Amurosaurus was similar to that of the lambeosaurine dinosaur Hypacrosaurus altispinus and was relatively larger than in most extant non-avian reptiles, including sauropod and ceratopsian dinosaurs. However, it was apparently relatively smaller than those of most theropod dinosaurs. The relatively large size of the cerebrum is consistent with the range and complexity of social behaviors inferred for lambeosaurine dinosaurs.