Estimated Body Mass Research Articles

Modern Tapirs as Morphofunctional Analogues for Locomotion in Endemic Eocene European Perissodactyls

Tapirs have historically been considered as ecologically analogous to several groups of extinct perissodactyls based on dental and locomotor morphology. Here, we investigate comparative functional morphology between living tapirs and endemic Eocene European perissodactyls to ascertain whether tapirs represent viable analogues for locomotion in palaeotheres and lophiodontids. Forelimb bones from 20 species of Eocene European perissodactyls were laser scanned and compared to a forelimb dataset of extant Tapirus. Bone shape was quantified using 3D geometric morphometrics; coordinates were Procrustes aligned and compared using Principal Component Analysis and neighbor-joining trees. Functional traits included lever-arm ratios (LARs; proxy for joint angular velocity), long-bone proportions (speed proxy), and estimated body mass. Results suggest that Paralophiodon and Palaeotherium magnum resemble Neotropical tapirs in humeral morphology and LARs. Palaeotheres demonstrate extensive forelimb shape disparity. Despite previous assessments, metacarpal shape analyzes do not support a strong morphological similarity between palaeotheres and tapirs, with Tapirus pinchaque representing the closest analogue for Eocene European equoid manus morphology. Our analyses suggest lophiodontids were not capable of moving as swiftly as tapirs due to greater loading over the manus. We conclude that the variation within modern tapir forelimb morphology confounds the assignment of one living analogue within Tapirus for extinct European equoids, whereas tapirs adapted for greater loading over the manus (e.g., T. bairdii, T. indicus) represent viable locomotor analogues for lophiodontids. This study represents a valuable first step toward locomotor simulation and behavioral inference for both hippomorph and tapiromorph perissodactyls in Eocene faunal communities.

The braincase of Malawisaurus dixeyi (Sauropoda: Titanosauria): A 3D reconstruction of the brain endocast and inner ear.

A braincase of the Cretaceous titanosaurian sauropod Malawisaurus dixeyi, complete except for the olfactory region, was CT scanned and a 3D rendering of the endocast and inner ear was generated. Cranial nerves appear in the same configuration as in other sauropods, including derived features that appear to characterize titanosaurians, specifically, an abducens nerve canal that passes lateral to the pituitary fossa rather than entering it. Furthermore, the hypoglossal nerve exits the skull via a single foramen, consistent with most titanosaurians, while other saurischians, including the basal titanosauriform, Giraffatitan, contain multiple rootlets. The size of the vestibular labyrinth is smaller than in Giraffatitan, but larger than in most derived titanosaurians. Similar to the condition found in Giraffatitan, the anterior semicircular canal is larger than the posterior semicircular canal. This contrasts with more derived titanosaurians that contain similarly sized anterior and posterior semicircular canals, congruent with the interpretation of Malawisaurus as a basal titanosaurian. Measurements of the humerus of Malawisaurus provide a body mass estimate of 4.7 metric tons. Comparison of body mass to radius of the semicircular canals of the vestibular labyrinth reveals that Malawisaurus fits the allometric relationship found in previous studies of extant mammals and Giraffatitan brancai. As in Giraffatitan, the anterior semicircular canal is significantly larger than is predicted by the allometric relationship suggesting greater sensitivity and slower movement of the head in the sagittal plane.

Scaling of swimming performance in baleen whales.

The scale dependence of locomotor factors has long been studied in comparative biomechanics, but remains poorly understood for animals at the upper extremes of body size. Rorqual baleen whales include the largest animals, but we lack basic kinematic data about their movements and behavior below the ocean surface. Here, we combined morphometrics from aerial drone photogrammetry, whale-borne inertial sensing tag data and hydrodynamic modeling to study the locomotion of five rorqual species. We quantified changes in tail oscillatory frequency and cruising speed for individual whales spanning a threefold variation in body length, corresponding to an order of magnitude variation in estimated body mass. Our results showed that oscillatory frequency decreases with body length (∝length-0.53) while cruising speed remains roughly invariant (∝length0.08) at 2 m s-1 We compared these measured results for oscillatory frequency against simplified models of an oscillating cantilever beam (∝length-1) and an optimized oscillating Strouhal vortex generator (∝length-1). The difference between our length-scaling exponent and the simplified models suggests that animals are often swimming non-optimally in order to feed or perform other routine behaviors. Cruising speed aligned more closely with an estimate of the optimal speed required to minimize the energetic cost of swimming (∝length0.07). Our results are among the first to elucidate the relationships between both oscillatory frequency and cruising speed and body size for free-swimming animals at the largest scale.

Fine scale geographic residence and annual primary production drive body condition of wild immature green turtles (Chelonia mydas) in Martinique Island (Lesser Antilles).

ABSTRACTThe change of animal biometrics (body mass and body size) can reveal important information about their living environment as well as determine the survival potential and reproductive success of individuals and thus the persistence of populations. However, weighing individuals like marine turtles in the field presents important logistical difficulties. In this context, estimating body mass (BM) based on body size is a crucial issue. Furthermore, the determinants of the variability of the parameters for this relationship can provide information about the quality of the environment and the manner in which individuals exploit the available resources. This is of particular importance in young individuals where growth quality might be a determinant of adult fitness. Our study aimed to validate the use of different body measurements to estimate BM, which can be difficult to obtain in the field, and explore the determinants of the relationship between BM and size in juvenile green turtles. Juvenile green turtles were caught, measured, and weighed over 6 years (2011–2012; 2015–2018) at six bays to the west of Martinique Island (Lesser Antilles). Using different datasets from this global database, we were able to show that the BM of individuals can be predicted from body measurements with an error of less than 2%. We built several datasets including different morphological and time-location information to test the accuracy of the mass prediction. We show a yearly and north–south pattern for the relationship between BM and body measurements. The year effect for the relationship of BM and size is strongly correlated with net primary production but not with sea surface temperature or cyclonic events. We also found that if the bay locations and year effects were removed from the analysis, the mass prediction degraded slightly but was still less than 3% on average. Further investigations of the feeding habitats in Martinique turtles are still needed to better understand these effects and to link them with geographic and oceanographic conditions.

Perception of body image and nutritional status in adolescents of public schools.

To assess body image dissatisfaction among adolescents from Northern Minas Gerais. This is a cross-sectional study with adolescents of both sexes, enrolled in the sixth to ninth year in the municipal public education network. A questionnaire was used, composed of sociodemographic and body image variables, which was obtained through a scale of silhouette figures. The anthropometric measurements of weight and height were performed to estimate body mass index. The correlation between the classification of the body mass index and the body image of adolescents was estimated through weighted Kappa. A total of 535 adolescents participated, and 24.5% had different classifications between the real and ideal body image. The Kappa index for the classification of body image was 0.51, 0.58 and 0.32 for the total of adolescents, girls and boys, respectively. Public school adolescents are dissatisfied with their self-body image.

Estimating body mass of Florida white-tailed deer from standard age and morphometric measurements

Context Measuring a mammal’s body mass has importance in understanding nutritional condition, reproductive biology and ecology. It can be impractical for a researcher to measure the body mass when equipment needed to weigh individuals is inadequate or unavailable. Aims The purpose of this study was to develop a model to accurately estimate the body mass of hunter-harvested Florida white-tailed deer (Odocoileus virginianus osceola, Odocoileus virginianus seminolus) based on the relationship between scale mass, sex and standard age and morphometric measurement predictor variables easily obtainable in the field. Methods An information-theoretic approach was used to evaluate simple and multiple linear regression models with 67% of the data, and the best model in the set was validated using the remaining 33%. Key results Chest girth was the best single predictor of body mass. A global model including sex, age, age2 and body length variables was better supported than chest girth alone, and subspecies information did not contribute significantly to the body-mass–predictor-variable relationship. The best model explained 98.5% of the variation in body mass as follows: body mass (kg) = –18.41 + 6.53 × sex (0 = female, 1 = male) + 5.04 × age (year) – 0.49 × age2 (year2) + 4.76 × 10−3 × chest girth2 (cm2) + 0.12 × body length (cm). The 95% confidence interval on the bias of the estimated body mass of the best model was –0.50 to 0.59 kg. The difference between estimated and scale body mass was –0.04 kg ± 0.28 (s.e.). Conclusions Individuals maintained a similar proportion of body mass to predictor variables, and differences between the observed and estimated body mass of model applied to the validation dataset were not significant. Implications The validated body-mass-estimation model presented will enable accurate estimates of the body mass of white-tailed deer in cases where standard age and morphometric measurements are available, but the individuals were not weighed. These results provide a basis to formulate and parameterise body-mass-estimation models for other white-tailed deer subspecies and populations. Without the need for specialised equipment, the body-mass-estimation model can be used by personnel involved in white-tailed deer research, management and sport hunting to assess trends in individual and population health in support of this species’ conservation. Photograph by Carlton Ward Jr.

Facial Adiposity, Attractiveness, and Health: A Review.

The relationship between facial cues and perceptions of health and attractiveness in others plays an influential role in our social interactions and mating behaviors. Several facial cues have historically been investigated in this regard, with facial adiposity being the newest addition. Evidence is mounting that a robust link exists between facial adiposity and attractiveness, as well as perceived health. Facial adiposity has also been linked to various health outcomes such as cardiovascular disease, respiratory disease, blood pressure, immune function, diabetes, arthritis, oxidative stress, hormones, and mental health. Though recent advances in the analysis of facial morphology has led to significant strides in the description and quantification of facial cues, it is becoming increasingly clear that there is a great deal of nuance in the way that humans use and integrate facial cues to form coherent social or health judgments of others. This paper serves as a review of the current literature on the relationship between facial adiposity, attractiveness, and health. A key component in utilizing facial adiposity as a cue to health and attractiveness perceptions is that people need to be able to estimate body mass from facial cues. To estimate the strength of the relationship between perceived facial adiposity and body mass, a meta-analysis was conducted on studies that quantified the relationship between perceived facial adiposity and BMI/percentage body fat. Summary effect size estimates indicate that participants could reliably estimate BMI from facial cues alone (r = 0.71, n = 458).

Advancing the use of morphometric data for estimating and managing common bottlenose dolphin (Tursiops truncatus) mass

AbstractKnowledge of a dolphin's body mass is central to establishing body condition, comparing across individuals, and designing successful management programs. In the present study, sex‐specific prediction equations for estimating body mass were generated from morphometrics (i.e., length and girth) and ages of bottlenose dolphins residing under professionally managed care. Measurements of wild dolphins in Sarasota Bay, Florida, were used to generate sex‐specific body mass reference ranges. Gompertz growth models were fitted to length measurements and age to compare growth across populations. From the regression analyses, the body mass of managed females (R2 = 0.937), managed males (R2 = 0.953), wild females (R2 = 0.979), and wild males (R2 = 0.972) were predicted with high levels of accuracy. Managed adults had similar or longer asymptotic lengths compared to their wild conspecifics. To apply this information, ZooMorphTrak, a mobile software application, was developed to provide a new resource for management. The “Approximate” feature was designed to approximate body mass based on user inputs of individual morphometrics. The “Management” feature compared a managed dolphin's known body mass with respect to body mass reference ranges generated from wild dolphins. ZooMorphTrak, developed by the Chicago Zoological Society, is available for download at http://itunes.apple.com.

Reconstructing body mass of the Australian dingo (Canis dingo) from two simple measurements of the hard palate

The ability to determine body mass from skulls is valuable for understanding various ecological, physiological, and evolutionary factors. In the Canidae, numerous methods to reconstruct body mass from measurements of the skull have been proposed, however there is no one-size fits all approach that can be applied across all species and subspecies. Added to this, current methods of reconstructing body mass are often complex, and have relatively high error rates. We aimed to produce a multivariate regression equation to estimate body mass of the Australian dingo (Canis dingo) from simple measurements of the skull, whilst ensuring that it could also be used in studies of encephalisation. To do this, we focussed on palate length (PL), palate width (PW) and the length of the first upper molar (M1). A total of 128 adult dingo (64 male; 64 female) crania from one region of Australia with known body mass were measured. Overall, the combination of PL and PW was the best predictor of body mass, with M1 having poor predictability. The model, mass (kg) = 0.246 ∗ (PL) + 0.320 ∗ (PW) − 24.757 produced a prediction error of 8.05%. Thus, these two measures of the palate provide simple and accurate predictors of body mass for the dingo. This will be useful for modern dingo specimens, as well as those found at archaeological sites and in museum collections that often consist of incomplete cranial material. The reconstruction of dingo body size is useful for evaluating variation in body mass through time, and across the Australian continent, particularly in the context of human activity.

Bariatric surgery reduces the risk of developing type 2 diabetes in severe obese subjects undergoing sleeve gastrectomy

BackgroundObesity is a major independent risk factor for developing type 2 diabetes (T2D). ObjectivesOur goal in this study was to analyze the impact of laparoscopic sleeve gastrectomy in the risk reduction of developing T2D in middle-aged, severely obese nondiabetes patients. SettingUniversity Hospital, United States. MethodsWe retrospectively reviewed our prospectively collected database from 2010 to 2016. All severely obese patients between 45 and 64 years of age without diabetes at baseline that underwent sleeve gastrectomy were included in our study. The T2D risk score for predicting the incidence of diabetes was measured preoperatively and at 12 months postoperatively and was based on the Framingham Offspring Study that calculates an 8-year risk of developing T2D. ResultsOf the 1330 patients included in this study, 6.5% (n = 86) met the criteria for the T2D risk score calculation. The population was predominantly composed of females (68.9%; n = 59) with a mean age of 52.8 ± 5.3 years. Preoperative body mass index was 43.1 ± 6.9 kg/m2 with a percentage of estimated body mass index loss and percentages of total weight loss were 72.2 ± 26.3% and 26.39 ± 18.15%, respectively, with fasting plasma glucose of 103.3 ± 14.9 mg/dL. The preoperative risk for T2D was 13.9 ± 11.6%, with an absolute risk reduction 12 months after surgery of 10.3%, corresponding to a 74.2% relative risk reduction. When comparing between sexes, risk reduction in females was slightly better than in males; however, this was not statistically significant. At 12-month follow-up, all measured variables were significantly improved, except for diastolic blood pressure. ConclusionsLaparoscopic sleeve gastrectomy significantly decreases the risk of developing T2D in middle-aged severely obese patients. Prospective studies are needed to further understand these findings.

Validation of age-based body mass estimation methods in toddlers and pre-school children

Background: Body mass is commonly used to determine medication dosages and equipment size. In emergency situations (including cases necessitating surgery) weighing paediatric patients can be imprac...

Architecture of the femoral and tibial diaphyses in relation to body mass and composition: Research from whole-body CT scans of adult humans.

Recent investigations have evaluated the influence of body composition on long bones in order to overcome the limits of body mass (BM) estimation methods and eventually lead to studying nutrition in past populations. Knowing how fat mass (FM) and fat-free mass (FFM) impact the skeleton would also enhance the understanding of mobility, activity, and locomotion derived from bone architecture. We investigated the relationship between BM and composition, and the architecture of the entire tibial and femoral diaphyses in an adult sample representative of a wide range of variation in age, BM, and composition. Body composition was measured directly from 78 whole-body CT scans for which the age, sex, BM, and stature were recorded. The entire diaphyseal thickness, volume, curvature, and cross-sectional geometry parameters of both the femur and tibia were numerically extracted. FM correlates with large portions of the femoral thickness in females only. FFM correlates with the femoral diaphysis in males but not in females. FFM correlates with the tibia architecture in both sexes, while FM is correlated in males exclusively. BM and body components influence the architecture of the diaphysis of lower limb long bones in sex-specific patterns that are mostly reflected in their thickness and can be recorded, in some cases, for their strength, rigidity, and volume. Our results suggest that (1) long bone diaphyses should be thoroughly studied, as a whole, when possible; and (2) BM and body components should be accounted for when deriving activity, mobility, or locomotion patterns from cortical bone.

Exploring bone volume and skeletal weight in the Middle Pleistocene humans from the Sima de los Huesos site (Sierra de Atapuerca, Spain).

Body mass estimation in fossil human species is a crucial topic in paleoanthropology as it yields information about ecologically relevant characteristics. Nevertheless, variables crucial to body mass estimation such as bone volume and skeletal weight have never before been calculated in a fossil human species. The exceptional state of preservation of several fossil human long bones from the Sima de los Huesos (SH) Middle Pleistocene site, in the Sierra de Atapuerca, makes it possible to calculate for the first time the absolute bone volume in five complete long bones (two femora and three humeri) of a fossil human species, an approach not possible in fragmentary or poorly preserved fossils. We have relied on computed tomography scans and 3D reconstructions to calculate bone volume. A sample of 62 complete bones of robust recent humans was also used for comparative purposes. The male SH femora (weight-bearing bones) and humeri (non-weight-bearing bones) have, relative to their size, greater bone volume (volume of bone tissue over total bone volume) than the equivalent bones in our recent human sample. As mass is volume × density, and bone tissue density (as a material) is similar across mammals, we calculate bone mass, and our results show that the SH hominins had on average heavier long bones than extant humans of the same size. From the femoral weight at hand, we have estimated the total skeletal weight in two SH individuals, which is about 36% heavier than in the recent humans of the equivalent body size. Using different methods and skeletal variables, including skeletal weight, to estimate body mass in these two SH humans, we highlight the considerable differences in body mass estimates we obtained, and that the largest body mass estimate is the one based on the skeletal weight. Our results suggest that we cannot assume the same relative proportion of bone volume and bone and skeletal weight characterized the entire genus Homo. Given that skeletal weight has a significant influence on body mass, current body mass estimates of fossil Homo specimens could be systematically underestimated. Thus, the significantly larger bone volume and heavier bones, probably throughout the entire skeleton, of SH humans could have had consequences for many biological parameters in this Pleistocene population and considerable importance for studies focusing on adaptive and ecologically relevant characteristics. Although more recent human samples should be analyzed, in our view, the high skeletal robusticity of the SH sample, including larger bone volume and skeletal weight, is part of their adaptive body type selected for throughout the Pleistocene to support different mechanical and activity regimes and formed under tight genetic control, including control over bone formative and regulatory processes.

Infant breastfeeding and childhood general, visceral, liver, and pericardial fat measures assessed by magnetic resonance imaging

Although a longer duration of breastfeeding has been associated with a lower risk of childhood obesity, the impact on specific organ fat depots is largely unknown. We examined the associations of any breastfeeding, duration and exclusiveness of breastfeeding, and of age at introduction of solid foods with measures of general, visceral, and organ adiposity at 10 y. In a population-based prospective cohort study in 4444 children, we obtained information on infant feeding by questionnaires. At the mean age of 9.8 y, we estimated body mass index from height and weight; fat mass index and fat-free mass index by dual-energy X-ray absorptiometry; and visceral fat index, pericardial fat index, and liver fat fraction by MRI. MRI scans were performed in a subgroup of 2646 children. After adjustment for age and sex, we observed associations of infant feeding with all general, visceral, and organ fat outcomes, except for pericardial fat index, at the age of 10 y. After further adjustment for family-based sociodemographic, maternal lifestyle-related, and childhood factors, only the associations of shorter breastfeeding duration and nonexclusive breastfeeding with a lower fat-free mass index remained significant (P <0.05). The associations of infant feeding with visceral fat index and liver fat fraction were attenuated to nonsignificant. Maternal education was found to be the strongest confounder. Our results suggest that the assoiations of any breastfeeding, duration and exclusiveness of breastfeeding, and age at the introduction of solid foods with general, visceral, and organ fat measures at the age of 10 y are largely explained by family-based sociodemographic factors.

New Metatherian Mammal from the Early Eocene of Antarctica

A new Paleogene metatherian from locality IAA 1/90, Marambio (Seymour) Island in the Antarctic Peninsula is described. Pujatodon ektopos, gen. et sp. nov., is recognized on the basis of a tiny lower left molar recovered from early Eocene (late Ypresian) levels of the Cucullaea I Allomember, La Meseta Formation. The tooth is characterized by its small size, bunoid aspect, short trigonid with closely set paraconid and metaconid, wide and long talonid, the development of an incipient cingulid at the labial base of the crown between the trigonid and talonid, and an expanded posterior cingulid. Body mass estimations for the new taxon range from 83.13 to 153.15 g. Its enamel microstructure shows the earliest evidence among metatherians of aligned prisms, as well as of interprismatic sheets of matrix. The analysis of other parameters, like body mass, molar morphometric index, and wear facets, suggests that the molars of Pujatodon were primarily adapted to the processing of fruits, nuts, seeds, and/or hard insects. Several features suggest the allocation of this specimen among basal polydolopimorphians (Prepidolopidae or, more probably, Glasbiidae). The discovery of the specimen MLP 14-I-10-20 could offer new insights on the origins and early diversification of Australidelphian marsupials in southern (and northern?) continents. It also adds significant information on the diversity of Antarctic Paleogene mammals, their evolution, habits, and historical biogeography.

Deciphering the isotopic niches of now-extinct Hispaniolan rodents

ABSTRACTHispaniola once had a large and diverse endemic rodent community. Today, a single species, Plagiodontia aedium, survives alongside invasive murids. Ecological adaptations and resource competition among species have not been previously studied. Here, we undertake the first investigation of the foraging ecology of the endemic taxa using estimated body mass and carbon and oxygen isotope values in incisor enamel. Our sample includes nine endemic taxa, eight of which are extinct, from two Holocene cave assemblages in southern Haiti. We also measured isotopic signatures for the invasive genus Rattus to explore potential niche overlap and competition between introduced and endemic fauna. We expected to detect isotopic evidence for niche partitioning among phylogenetically related rodents with similar morphological adaptations. We find clear differences in body mass and isotope values among rodent taxa. The combination of carbon and oxygen isotopes suggests that some taxa lived in the forest understory, whereas others likely frequented the canopy or open habitats. We may also be able to distinguish dietary preferences (e.g., folivory, frugivory, and potentially trophic omnivory). Small individuals attributed to an undescribed species of Isolobodon are isotopically distinct from their congeners, I. montanus and I. portoricensis, and appear to have relied to a modest degree on C4 foods. Rattus had a broad generalist niche, which coincided with several endemics, including extant P. aedium. Although preliminary, these data shed light on how a closely related community of island rodents partitions resources and provide context for understanding the ecological role that invasive species may play in extinction processes and future conservation efforts.

New middle Eocene omomyines (Primates, Haplorhini) from San Diego County, California

The Friars Formation of San Diego County, California, has yielded a middle Eocene mammalian fauna from the early part of the Uintan North American Land Mammal Age. Prior research on the primate fauna from the Friars Formation provides evidence of one notharctine and multiple omomyine species, but many specimens collected since the early 1980s remain unstudied. Here we describe three new omomyine genera from the Friars Formation. These new taxa range in estimated body mass from about 119 g to 757 g, and substantially expand the diversity of middle Eocene omomyoids known from Southern California. Resolution of the phylogenetic relationships of the new Friars Formation omomyines is complicated by the fact that different character-taxon matrices and tree building methods produce different results. Nevertheless, all preliminary phylogenetic analyses are congruent in recovering a close relationship between the three new genera and the omomyines Macrotarsius, Omomys, Ourayia, and Utahia. Prior research has documented a shift in omomyoid diversity in North America from the anantomophine-rich Bridgerian to the omomyine-rich Uintan. Our description of three new Uintan omomyine taxa from the Friars Formation further emphasizes these opposite trends in anaptomorphine and omomyine species richness during the middle Eocene. All three of the new taxa are currently known from only the Friars Formation in San Diego County, California. Four of the previously known omomyoid genera from Southern California (Dyseolemur, Chumashius, Yaquius, and Stockia) are also endemic to the region, further highlighting the provincial character of primate faunas in Utah, Southern California, and West Texas during the Uintan.

Thermal environment sensor array: Part 1 development and field performance assessment

Current thermal environment (TE) monitoring and control strategies for livestock and poultry facilities require enhanced measurement capabilities to provide an optimum TE based on the animals' thermal demands. Further, techniques for combining additional parameters are needed to adequately assess the total impact of the TE on the animals. Hence, two papers introduce a spatial network of 44 Thermal Environment Sensor Arrays (TESAs), each with a custom data acquisition system (Part 1) and a technique for evaluating the TE as a function of mean body temperature difference from thermally comfortable pigs using estimated body mass and TESA measurements as inputs (Part 2). The TESAs and new thermal index were deployed in a commercial pig facility to perform a preliminary assessment of robustness and capabilities under production settings. Each TESA measured dry-bulb temperature (Tdb), black globe temperature, airspeed, and relative humidity (RH), and required a custom circuit board with a microcontroller, signal conditioning, and communication hardware. After closeout (completion of the production cycle), TESAs were validated with a reference system to determine individual time constants and assess if a significant bias correction was needed (except airspeed). Total number of usable measurements for subsequent analysis for all sensors per TESA averaged (95% CI) 202,310 (199,187; 205,437). In summary, 7% Tdb thermistor, 9% digital Tdb, and 27% RH sensors required correction after 170 d inside the facility. Utilisation of low-cost sensors, open-source software, and microcontrollers allowed this novel network to provide sufficient measurement density to promote future queries on TE data in animal facilities.

The Morphology of the Bovid Calcaneus: Function, Phylogenetic Signal, and Allometric Scaling

Despite its clear functional role in hock (ankle) plantarflexion, the bovid calcaneus has been understudied with respect to the functional constraints imposed by locomotion in differing habitats, the allometric influence of inter-specific body size differences, and phylogenetic signal. This study uses a comparative sample of extant bovid species to shed light on the evolution of bovid calcaneal morphology. I measured eight linear measurements on 204 calcaneus specimens representing 41 extant bovid species. Using a morphological body size proxy validated against published species-mean body mass estimates, I performed Ordinary Least Squares regression to examine the allometric relationships of each measurement with body size. I classified each bovid species to a preferred habitat type based on published literature, and performed Phylogenetic Generalized Least Squares (PGLS) to test for differences in morphology between bovid taxa with different preferred habitats while considering evolutionary relatedness. I visualized morphological differences between taxa using Principal Components Analysis plotted in a phylomorphospace. Results demonstrate that several measurements of the bovid calcaneus have an allometric relationship to body size. The functional length of the calcaneus scales with negative allometry, which likely maintains a comparable safety factor within the calcaneal tuber at larger body sizes. While open-habitat bovids have relatively shorter calcaneal tubers, this difference is not significant when controlling for the influence of body size and phylogenetic signal using PGLS. Among bovid tribes that have a deep evolutionary history of adaptation to open habitats, Antilopini have relatively longer calcaneal tubers than Alcelaphini or Hippotragini, which may reflect the unique importance of stotting behavior in predator avoidance among antelopins. Overall, the morphology of the bovid calcaneus has been shaped by a complex interaction of phylogenetic and body-size constraints as well as adaptation to modes of predator avoidance mediated by preferred habitat.

A diachronic examination of biomechanical changes in skeletal remains from Tombos in ancient Nubia

Using morphometric assessment, we diachronically analyse mechanical stress and limb function at the Tombos (modern Sudan) archaeological site through time and changing socioeconomic circumstances. Based on previous research, we expect that during the Third Intermediate/Napatan (c. 1070–656 BCE) people were larger and more physically active than in the New Kingdom (∼1400–1070 BCE). On the appendicular skeleton of adults 57 measurements were obtained on individuals from 67 discrete burials and 370 commingled skeletal elements. These raw measurements were analysed statistically. Individuals from the discrete burials were used to calculate body mass and estimate mechanical behaviour (torsional and bending rigidity of long bones) modeled using beam theory across several bones of the upper and lower limbs. Body mass estimates for both sexes show people during the Third Intermediate/Napatan period were statistically significantly larger. On the upper limb for both sexes, variation reflects joint stabilisation and actions of flexion and extension at the elbow and/or supination/pronation of the forearm. On the lower limb, females show variation related to weight bearing activities and foot flexion; male variation is related to weight bearing activities, joint movement and stabilisation. These data point to altered habitual behaviour and physical activity for both sexes at Tombos through time. Suggested causes for both sexes include increased agricultural activities, and for males increased granite quarrying and equestrian activities. Using analyses of multiple bones of the upper and lower limbs in conjunction with biomechanical analyses, this study demonstrates the importance of the examination of physical activities in past populations, highlighting changes that can occur with sociopolitical transitions.