CARNIVORA FROM THE EARLY PLEISTOCENE OF GRĂUNCEANU (OLTEŢ RIVER VALLEY, DACIAN BASIN, ROMANIA)

The Grăunceanu site in the Olteţ River Valley has yielded a rich carnivoran assemblage including at least 10, possibly 11 species: Vulpes alopecoides, Nyctereutes megamastoides, Ursus etruscus, Meles thorali, Lutraeximia sp., Pliocrocuta perrieri, Lynx issiodorensis, Puma pardoides, Megantereon cultridens, Homotherium latidens and possibly Pachycrocuta brevirostris. The faunal assemblage is compared with approximately coeval sites Europe and western Asia. This comparative analysis shows that the Grăunceanu assemblage shows the greatest similarities with sites to the west such as Senèze and, particularly, Saint-Vallier, rather than more easternly ones such as Liventsovka and Dmanisi. The relative abundance of the taxa at Grăunceanu was compared to that of Saint-Vallier and broad similarities were found, except for the absence of some cursorially adapted taxa present at Saint-Vallier but absent from Grăunceanu. The absence at Grăunceanu of taxa with a reconstructed cursorial hunting strategy, such as Chasmaporthetes and Acinonyx, may suggest less open habitat at Grăunceanu than indicated in previous paleoenvironmental reconstructions

Individual variation of the masticatory system dominates 3D skull shape in the herbivory-adapted marsupial wombats

BackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses - particularly those produced through mastication of tough food items - may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, allometry may not dominate within-species shape variation, even if it is a driver of evolutionary shape divergence; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of three species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraints act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species

The role of networks to overcome large-scale challenges in tomography : the non-clinical tomography users research network

Our ability to visualize and quantify the internal structures of objects via computed tomography (CT) has fundamentally transformed science. As tomographic tools have become more broadly accessible, researchers across diverse disciplines have embraced the ability to investigate the 3D structure-function relationships of an enormous array of items. Whether studying organismal biology, animal models for human health, iterative manufacturing techniques, experimental medical devices, engineering structures, geological and planetary samples, prehistoric artifacts, or fossilized organisms, computed tomography has led to extensive methodological and basic sciences advances and is now a core element in science, technology, engineering, and mathematics (STEM) research and outreach toolkits. Tomorrow's scientific progress is built upon today's innovations. In our data-rich world, this requires access not only to publications but also to supporting data. Reliance on proprietary technologies, combined with the varied objectives of diverse research groups, has resulted in a fragmented tomography-imaging landscape, one that is functional at the individual lab level yet lacks the standardization needed to support efficient and equitable exchange and reuse of data. Developing standards and pipelines for the creation of new and future data, which can also be applied to existing datasets is a challenge that becomes increasingly difficult as the amount and diversity of legacy data grows. Global networks of CT users have proved an effective approach to addressing this kind of multifaceted challenge across a range of fields. Here we describe ongoing efforts to address barriers to recently proposed FAIR (Findability, Accessibility, Interoperability, Reuse) and open science principles by assembling interested parties from research and education communities, industry, publishers, and data repositories to approach these issues jointly in a focused, efficient, and practical way. By outlining the benefits of networks, generally, and drawing on examples from efforts by the Non-Clinical Tomography Users Research Network (NoCTURN), specifically, we illustrate how standardization of data and metadata for reuse can foster interdisciplinary collaborations and create new opportunities for future-looking, large-scale data initiatives

Craniofacial Fluctuating Asymmetry in Gorillas, Chimpanzees, and Macaques

Objectives Craniofacial fluctuating asymmetry (FA) refers to the random deviations from symmetry exhibited across the craniofacial complex and can be used as a measure of developmental instability for organisms with bilateral symmetry. This article addresses the lack of data on craniofacial FA in nonhuman primates by analyzing FA magnitude and variation in chimpanzees, gorillas, and macaques. We offer a preliminary investigation into how FA, as a proxy for developmental instability, varies within and among nonhuman primates. Materials and Methods We generated 3D surface models of 121 crania from Pan troglodytes troglodytes, Gorilla gorilla gorilla, and Macaca fascicularis fascicularis. Using geometric morphometric techniques, the magnitude of observed FA was calculated and compared for each individual, sex, and taxon, along with the variation of FA across cranial regions and for each bilateral landmark. Results Gorillas and macaques exhibited higher and more similar magnitudes of FA to each other than either taxon did to chimpanzees; variation in magnitude of FA followed this same trend. No significant differences were detected between sexes using pooled data across species, but sex did influence FA magnitude within taxa in gorillas. Further, variation in FA variance across cranial regions and by landmark was not distributed in any particular pattern. Conclusion Possible environmentally induced causes for these patterns of FA magnitude include differences in growth rate and physiological stress experienced during life. Developmental stability may be greatest in chimpanzees in this sample. Additionally, these results point to appropriate landmarks for future FA analyses and may help suggest more urgent candidate taxa for conservation efforts

Skeletal age during hurricane impacts fluctuating asymmetry in Cayo Santiago rhesus macaques

Abstract As natural disasters become more frequent due to climate change, understanding the biological impact of these ecological catastrophes on wild populations becomes increasingly pertinent. Fluctuating asymmetry (FA), or random deviations from bilateral symmetry, is reflective of developmental instability and has long been positively associated with increases in environmental stress. This study investigates craniofacial FA in a population of free‐ranging rhesus macaques (Macaca mulatta) that has experienced multiple Category 3 hurricanes since the colony's inception on Cayo Santiago, including 275 individuals from ages 9 months to 31 years (F = 154; M = 121). Using geometric morphometrics to quantify FA and a linear mixed‐effect model for analysis, we found that sex, age, and decade of birth did not influence the amount of FA in the individuals included in the study, but the developmental stage at which individuals experienced these catastrophic events greatly impacted the amount of FA exhibited (p = .001). Individuals that experienced these hurricanes during fetal life exhibited greater FA than any other post‐natal developmental period. These results indicate that natural disasters can be associated with developmental disruption that results in long‐term effects if occurring during the prenatal period, possibly due to increases in maternal stress‐related hormones

Functional Correlates of the Position of the Axis of Rotation of the Mandible During Chewing in Non-Human Primates

The location of the axis of rotation (AoR) of the mandible was quantified using the helical axis (HA) in eight individuals from three species of nonhuman primates: Papio anubis, Cebus apella, and Macaca mulatta. These data were used to test three hypotheses regarding the functional significance of anteroposterior condylar translation – an AoR located inferior to the temporomandibular joint (TMJ) – during chewing: minimizing impingement of the gonial region on cervical soft tissue structures during jaw opening; avoiding stretching of the inferior alveolar neurovascular bundle (IANB); and increasing jaw-elevator muscle torques. The results reveal that the HA is located near the occlusal plane in Papio and Cebus, but closer to the condyle in Macaca; is located anteroinferior to the TMJ during both opening and closing in Papio, as well as during opening in Macaca and Cebus; and varies in its location during closing in Macaca and Cebus. The impingement hypothesis is not supported by interspecific variation in HA location: species with larger gonial angles like Cebus do not have more inferiorly located HAs than species with more obtuse mandibular angles like Papio. However, intraspecific variation provides some support for the impingement hypothesis. The HA seldom passes near or through the lingula, falsifying the hypothesis that its location is determined by the sphenomandibular ligament, and the magnitudes of strain associated with a HA at the TMJ would not be large enough to cause problematic stretching of the IANB. HA location does affect muscle moment arms about the TMJ, with implications for the torque generation capability of the jaw-elevator muscles. In Cebus, a HA farther away from the TMJ is associated with larger jaw-elevator muscle moment arms about the joint than if it were at the TMJ. The effects of HA location on muscle strain and muscle moment arms are largest at large gapes and smallest at low gapes, suggesting that if HA location is of functional significance for primate feeding system performance, it is more likely to be in relation to large gape feeding behaviors than chewing. Its presence in humans is most parsimoniously interpreted as a primitive retention from nonhuman primate ancestors and explanations for the presence of AP condylar translation in humans need not invoke either the uniqueness of human speech or upright posture