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A method was developed for determining the age and sex of the water vole (Arvicola amphibius L.) based on the measurements of the pelvic limb bones. The material was obtained from captive-bred animals of a known age. By using discriminant analysis, classification functions were found for dividing the animals of the sample analyzed (n = 56) by sex and age with an accuracy equal to one year. Testing the control group (n = 34) showed that the age of 90.0% of males and of 92.9% of females was determined correctly. The correctness of the classification by sex is 100%.

Organs are composites of tissue types with diverse developmental origins, and they rely on distinct stem and progenitor cells to meet physiological demands for cellular production and homeostasis. How diverse stem cell activity is coordinated within organs is not well understood. Here we describe a lineage-restricted, self-renewing common skeletal progenitor (bone, cartilage, stromal progenitor; BCSP) isolated from limb bones and bone marrow tissue of fetal, neonatal, and adult mice. The BCSP clonally produces chondrocytes (cartilage-forming) and osteogenic (bone-forming) cells and at least three subsets of stromal cells that exhibit differential expression of cell surface markers, including CD105 (or endoglin), Thy1 [or CD90 (cluster of differentiation 90)], and 6C3 [ENPEP glutamyl aminopeptidase (aminopeptidase A)]. These three stromal subsets exhibit differential capacities to support hematopoietic (blood-forming) stem and progenitor cells. Although the 6C3-expressing subset demonstrates functional stem cell niche activity by maintaining primitive hematopoietic stem cell (HSC) renewal in vitro, the other stromal populations promote HSC differentiation to more committed lines of hematopoiesis, such as the B-cell lineage. Gene expression analysis and microscopic studies further reveal a microenvironment in which CD105-, Thy1-, and 6C3-expressing marrow stroma collaborate to provide cytokine signaling to HSCs and more committed hematopoietic progenitors. As a result, within the context of bone as a blood-forming organ, the BCSP plays a critical role in supporting hematopoiesis through its generation of diverse osteogenic and hematopoietic-promoting stroma, including HSC supportive 6C3(+) niche cells.

Zooarchaeological research at Qesem Cave, Israel demonstrates that large-game hunting was a regular practice by the late Lower Paleolithic period. The 400- to 200,000-year-old fallow deer assemblages from this cave provide early examples of prime-age-focused ungulate hunting, a human predator-prey relationship that has persisted into recent times. The meat diet at Qesem centered on large game and was supplemented with tortoises. These hominins hunted cooperatively, and consumption of the highest quality parts of large prey was delayed until the food could be moved to the cave and processed with the aid of blade cutting tools and fire. Delayed consumption of high-quality body parts implies that the meat was shared with other members of the group. The types of cut marks on upper limb bones indicate simple flesh removal activities only. The Qesem cut marks are both more abundant and more randomly oriented than those observed in Middle and Upper Paleolithic cases in the Levant, suggesting that more (skilled and unskilled) individuals were directly involved in cutting meat from the bones at Qesem Cave. Among recent humans, butchering of large animals normally involves a chain of focused tasks performed by one or just a few persons, and butchering guides many of the formalities of meat distribution and sharing that follow. The results from Qesem Cave raise new hypotheses about possible differences in the mechanics of meat sharing between the late Lower Paleolithic and Middle Paleolithic.

Sauropods were the largest terrestrial tetrapods (>10⁵ kg) in Earth's history and grew at rates that rival those of extant mammals. Magyarosaurus dacus, a titanosaurian sauropod from the Upper Cretaceous (Maastrichtian) of Romania, is known exclusively from small individuals (<10³ kg) and conflicts with the idea that all sauropods were massive. The diminutive M. dacus was a classical example of island dwarfism (phyletic nanism) in dinosaurs, but a recent study suggested that the small Romanian titanosaurs actually represent juveniles of a larger-bodied taxon. Here we present strong histological evidence that M. dacus was indeed a dwarf (phyletic nanoid). Bone histological analysis of an ontogenetic series of Magyarosaurus limb bones indicates that even the smallest Magyarosaurus specimens exhibit a bone microstructure identical to fully mature or old individuals of other sauropod taxa. Comparison of histologies with large-bodied sauropods suggests that Magyarosaurus had an extremely reduced growth rate, but had retained high basal metabolic rates typical for sauropods. The uniquely decreased growth rate and diminutive body size in Magyarosaurus were adaptations to life on a Cretaceous island and show that sauropod dinosaurs were not exempt from general ecological principles limiting body size.

•Age estimation of growing dogs is becoming important in forensic veterinary medicine.•A historical overview of the radiology and anatomy literature has been performed.•X-ray evaluation of limbs ossification centers enables estimating the age of a puppy.•User-friendly tables for puppy age estimation have been proposed.•Methodology may be improved to enhance the accuracy in estimate the age of puppies. Age estimation in growing dogs is crucial not only in clinical practice but increasingly so in forensic practice as well. In the last few years, it has assumed great importance for correctly identifying the age of puppies illegally imported to Italy as well as to other European countries. Puppies are, in fact, transported when they are too young to be moved, which can cause both animal/public health and animal welfare issues. Therefore, the movement of animals within the European Community is governed by strict rules, and veterinarians are often required to evaluate the age of the imported puppies in a forensic scenario as accurately as possible. To date, X-ray evaluation of limb bones ossification centers (OCs) is generally accepted as a valid tool to assess the age of puppies. A wealth of information exists on this topic but it is not always easily available. This work is a historical review of the existing literature and proposes two tables illustrating the timelines of limb OCs appearance and closure, coming to terms with forensic requests to evaluate the age of a puppy. The timelines reported indicate the need to improve methodology to enhance the accuracy and to reduce the error in age estimation.

Studying fossils from a mass-mortality event reveals evidence for sexual dimorphism and, unusually, equal numbers of males and females in a herd of dinosaurs.Studying fossils from a mass-mortality event reveals evidence for sexual dimorphism and, unusually, equal numbers of males and females in a herd of dinosaurs.

The aim of this study was to identify the presence and magnitude of right–left asymmetry in the fore- and hindlimb long bones of adult guinea pigs (Cavia porcellus), and, in parallel, to evaluate sex-related differences in shape and size in the same bones. For this purpose, the stylopodium and zeugopodium bones were analyzed together. Computed tomography data were obtained from all animals under a standard protocol, three-dimensional bone models were generated from these datasets, and these models formed the basis for the geometric morphometric analyses. The analyses showed that sex accounted for a small but consistent proportion of shape variation (approximately 5–7%) in the antebrachium, femur and crus, whereas this effect was more limited in the humerus. Asymmetry analysis based on paired right–left data revealed that directional asymmetry was generally low, whereas fluctuating asymmetry varied across bones. The highest asymmetry was detected in the antebrachium, the crus showed an intermediate level, and the stylopodial elements, humerus and femur, were comparatively more symmetrical. This pattern is consistent with the biomechanical expectation that small right–left deviations tend to accumulate in distal and functionally more active forelimb segments that are positioned farther from the trunk. In conclusion, the findings indicate that asymmetry arises gradually as a function of bone position and functional use rather than from a single growth error, and that distal forelimb elements should therefore be given particular attention in asymmetry studies.

The vertebrate body is a highly modular system within which evolutionary adaptation is expected to occur synchronously at a variety of hierarchical scales, from single tissue to whole organism. For example, the evolution of different body shapes, associated with disparate locomotor ecologies, will affect the loading regimes experienced by limbs, and may therefore be coupled with adaptations to limb bone morphology. However, such a relationship between body shape, limb loading and bone morphology has not been tested. Here, we find significant positive relationships between whole-body relative anteroposterior centre of mass and the robusticity of the humeral shaft relative to the femoral shaft across a disparate sample of tetrapods. As centre of mass shifts towards the shoulder, the humerus becomes proportionally more robust. However, the magnitude of this increased robusticity and the anatomical planes across which it occurs vary between tetrapod clades, reflecting the different limb loading regimes imposed by postural differences. These relationships illuminate the osteological adaptations associated with variation in mass distribution and limb posture, and provide a framework within which centres of mass in fossil tetrapods such as dinosaurs can be predicted, opening the door to large-scale studies of tetrapod centre of mass and body plan macroevolution.

•Eleven equations for sorting commingled upper limb bones are produced.•The regression equations can be applied in fragmented skeletal elements.•The method is applicable in skeletal samples of mixed sex and anatomical side.•A combined osteometric and morphoscopic approach can lead to a reliable sorting. The major upper limb skeletal elements (scapulae, humeri, ulnae and radii) are frequently utilized for sex determination and stature estimation. Consequently, in forensic cases that involve commingled remains, it is crucial to reassociate the aforementioned bones and attribute them to the right individual. The aim of the present study is to develop simple and multiple regression equations for sorting commingled human skeletal elements of the upper limb. In that context, ten common anthropological linear measurements of the articular surfaces of scapulae, humeri, ulnae, and radii were performed on 222 adult skeletons from the Athens Collection. The functions developed for sorting adjoining bones presented a strong positive linear relationship (r=0.69–0.93, p<0.05). The values of the determination coefficient statistics (r2=0.47–0.86) were found to be high and those of the standard errors of the estimate were found to be low (SEE=0.88–1.61). Blind tests indicated that when metric and morphoscopic sorting techniques are combined, a reliable sorting of the skeletal elements of the upper limbs is possible.

Sexual dimorphism is challenging to detect among fossils due to a lack of statistical representativeness. The Angeac-Charente Lagerstätte (France) represents a remarkable ‘snapshot’ from a Berriasian (Early Cretaceous) ecosystem and offers a unique opportunity to study intraspecific variation among a herd of at least 61 coeval ornithomimosaurs. Herein, we investigated the hindlimb variation across the best-preserved specimens from the herd through 3D Geometric Morphometrics and Gaussian Mixture Modeling. Our results based on complete and fragmented femora evidenced a dimorphism characterized by variations in the shaft curvature and the distal epiphysis width. Since the same features vary between sexes among modern avian dinosaurs, crocodilians, and more distant amniotes, we attributed this bimodal variation to sexual dimorphism based on the extant phylogenetic bracketing approach. Documenting sexual dimorphism in fossil dinosaurs allows a better characterization and accounting of intraspecific variations, which is particularly relevant to address ongoing taxonomical and ecological questions relative to dinosaur evolution.