Since the description of Isisfordia duncani, a number of new extinct species and revisions of previously described species have prompted a variety of contradicting phylogenetic hypotheses on the topology of Neosuchia. As a consequence, a consensus on the rooting of Eusuchia in relation to other neosuchian clades has not been reached and the origin of the group remains unsettled. Exemplifying this, Bernissartia fagesii, from the Early Cretaceous of Belgium, has long been considered a key taxon for understanding the origin of Eusuchia, but more recent hypotheses found support for a more basal position, as an ally to goniopholidids, paralligatorids or atoposaurids. Because many details of the anatomy of the type specimen are hidden by glue and the sediment adhering to the fossils, a number of characters are pending confirmation. Based on computed tomography data, we extract bones of the cranium and mandibles, describe new characters and re-evaluate anatomical details in the lectotype specimen. Our phylogenetic analysis confirms that B. fagesii is a derived neosuchian, unrelated to atoposaurids, goniopholidids and paralligatorids. We recover B. fagesii and Koumpiodontosuchus aprosdokiti in a basal position within Eusuchia, together with Susisuchidae, a group of gondwanan neosuchians containing Susisuchus and Isisfordia, which here form a polytomy with Hylaeochampsidae. The presence/absence of pterygoid-bound internal choanae cannot be used to fully resolve relationships at the neosuchian–eusuchian transition because of the variability of this character even at the familial level, as recently reported within susisuchids and bernissartiids. There is no doubt that true eusuchians were present in Laurasia as early as the Early Cretaceous, the hylaeochampsid Hylaeochampsa vectiana being the oldest (Barremian) undoubted representative. But whether the Eusuchia were also present in southern landmasses depends on solving the phylogenetic position of susisuchids and other less known gondwanan forms within or outside Eusuchia.
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RBINS Staff Publications 2020
Objectives Harris lines (HLs) are defined as transverse, mineralized lines associated with temporary growth arrest. In paleopathology, HLs are used to reconstruct health status of past populations. However, their etiology is still obscure. The aim of this article is to test the reliability of HLs as an arrested growth marker by investigating their incidence on human metrical parameters. Methods The study was performed on 69 individuals (28 adults, 41 subadults) from the Dendermonde plague cemetery (Belgium, 16th century). HLs were rated on distal femora and both ends of tibiae. Overall prevalence and age-at-formation of each detected lines were calculated. ANOVA analyses were conducted within subadult and adult samples to test if the presence of HLs did impact size and shape parameters of the individuals. Results At Dendermonde, 52% of the individuals had at least one HL. The age-at-formation was estimated between 5 and 9 years old for the subadults and between 10 and 14 years old for the adults. ANOVA analyses showed that the presence of HLs did not affect the size of the individuals. However, significant differences in shape parameters were highlighted by HL presence. Subadults with HLs displayed slighter shape parameters than the subadults without, whereas the adults with HLs had larger measurements than the adults without. Conclusions The results suggest that HLs can have a certain impact on shape parameters. The underlying causes can be various, especially for the early formed HLs. However, HLs deposited around puberty are more likely to be physiological lines reflecting hormonal secretions.
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RBINS Staff Publications 2016
Abstract: Easter Island (or Rapa Nui), famous worldwide for its gigantic stone statues, is the most isolated inhabited island in the Pacific. Yet the history of its inhabitants has been far from peaceful: they have faced deforestation, slave raids, epidemics and colonialism. This paper aims to study the diet of the ancient Easter Islanders and focuses on dietary reconstruction through the analysis of human teeth and bones, more particularly, on the impact of gender, age, social status and spatial distribution. However, retrieving information on their dietary habits is difficult, due to the absence of written archives and the disappearance of most of the bearers of the indigenous culture during the slave raids and epidemics of the nineteenth century. Therefore our primary source of direct information are food remains (animal bones and plant remnants) and human bones. The individuals studied came from twenty sites, which date mainly from the seventeenth to the nineteenth centuries. The greater part had been buried in monuments (funerary stone platforms called ahu), or caves. These individuals are currently stored at the Royal Belgian Institute of Natural Sciences and the Father Sebastian Englert Anthropological Museum of Easter Island. Dietary reconstruction is based on stress indicators, dental microwear and stable carbon and nitrogen isotope analyses. Stress indicators are skeletal markers which reveal poor living conditions during growth. Two indicators were studied: dental enamel hypoplasia (localised defects in the tooth crown generally expressed in the form of horizontal depressions) and cribra orbitalia(porotic lesions in the bony orbital roof). Dental microwear is the study of the microscopic features that form on the teeth’s surfaces as a result of use. Their density, dimensions, and orientation are a direct result of diet. Stable isotope analyses are based on the fact that the isotopic composition of an individual’s tissues is determined by the proportion of the various foods consumed. Carbon and nitrogen stable isotope composition were analysed in the bone collagen. Dental microwear patterns indicated a large proportion of tubers in the Easter islanders’ diet. Additionally, the stable isotopes showed that, on average, one third of the dietary proteins were of marine origin and that children were breastfed until three years of age. Stress indicators suggest that infantile malnutrition was not severe. Our results also demonstrated gender disparity in access to food resources. Furthermore, the isotopic signatures clustered according to the place of burial (ahu), indicating family dietary specificities. Finally, our study revealed the influence of social status on food intake: individuals from Ahu Nau Nau, which is said to be the royal ahu, displayed the highest value of nitrogen and carbon isotopes and the lowest number of microwear features. A greater consumption of marine products may explain this distinction.
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RBINS Staff Publications 2016
