Traditional Morphometric Methods Research Articles

Geometric morphometric methods for identification of oyster species based on morphology.

Both genetic and environmental factors affect the morphology of oysters. Molecular identification is currently the primary means of species identification, but it is inconvenient and costly. In this research, we evaluated the effectiveness of geometric morphometric (GM) techniques in distinguishing between two oyster species, Crassostreagigas and C.ariakensis. We used traditional morphometric and GM methods, including principal component analysis (PCA), thin-plate spline analysis (TPS) and canonical variable analysis (CVA), to identify specific features that distinguish the two species. We found that differences in shape can be visualised using GM methods. The Procrustes analysis revealed significant differences in shell morphology between C.gigas and C.ariakensis. The shells of C.ariakensis are more prominent at the widest point and are more scattered and have a greater variety of shapes. The shells of C.gigas are more oval in shape. PCA results indicated that PC1 explained 45.22%, PC2 explained 22.09% and PC3 explained 10.98% of the variation between the two species, which suggests that the main morphological differences are concentrated in these three principal components. Combining the TPS analysis function plots showed that the shell shape of C.ariakensis is mainly elongated and spindle-shaped, whereas the shell shape of C.gigas is more oval. The CVA results showed that the classification rate for the two species reached 100% which means that C.ariakensis and C.gigas have distinct differences in shell morphology and can be completely separated, based on morphological characteristics. Through these methods, a more comprehensive understanding of the morphological characteristics of different oyster populations can be obtained, providing a reference for oyster classification and identification.

3D Morphological Scanning and Environmental Correlates of Bufo gargarizans in the Yellow River Basin

Morphology plays a crucial role in understanding the intricacies of biological forms. Traditional morphometric methods, focusing on one- or two-dimensional geometric levels, often fall short of accurately capturing the three-dimensional (3D) structure of organisms. The advent of 3D scanning techniques has revolutionized the study of organismal morphology, enabling comprehensive and accurate measurements. This study employs a 3D structured light scanning system to analyze the morphological variations in the Chinese toad (Bufo gargarizans Cantor, 1842) along the Yellow River Basin. The 3D digital model obtained from the scan was used to calculate various morphological parameters including body surface area, volume, fractal dimensions, and limb size. The research explores geographic variability patterns and identifies environmental drivers affecting the 3D phenotypic variation of B. gargarizans. Results reveal a bimodal pattern of variation in the toad population, with higher elevations exhibiting smaller body sizes, greater appendage proportions, and more complex body structures. Linear regression analyses highlight the influence of elevation and annual mean temperature on the morphological variation of B. gargarizans, with elevation playing a significant role. This study underscores the significance of 3D morphometric analysis in unraveling the intricacies of organismal morphology and understanding the adaptive strategies of species in diverse environments.

Evaluation of sex differences in pelvis and femur x-ray images in British shorthair cats by geometric morphometric method.

The study covers British Shorthair cats, which is a popular domestic cat breed in our country and defined as 'brachycephalic' in terms of skull structure. Article focuses on the pelvis and femur region of cats which gynaecological and orthopaedic diseases of this cat breed, which are frequently encountered in clinical practice, is found to be important. It is aimed to reveal the shape differences between male and female individuals using geometric morphometric method. X-ray images were used to examine the pelvis and femurs of cats via geometric method. Radiological images were obtained from a total of 40 British Shorthair cats (20 females and 20 males) in two positions, ventro-dorsal (VD) and latero-lateral (LL), and shape differences between the sexes were examined. As result, it is seen that the measurement points taken from the males are more outward and have sharper angles than the females. Study also shows pelvis is a better choice than femur when it comes to sex discrimination. Although traditional morphometric methods are more useful in clinical practice, it is thought that is important to support or re-evaluate the data with the geometric morphometric method in academic field for a further approach.

Predictive use of modern reference osteological collections for disentangling the shape of Eurasian equid cheek teeth and metapodials in archaeological material

AbstractEquids have shaped past Eurasian societies in many ways. This applies in particular to domestic horses, donkeys, and their hybrids. Key to documenting modes of exploitation and cultural trajectories in past societies is the correct taxonomic classification of tooth and bone specimens found in archaeological sites. However, close osteomorphological resemblance of wild and domestic equids and their economically valuable hybrids, that is, mules and hinnies, complicates the identification of intentionally fragmented or naturally damaged archaeological specimens. Here, we apply geometric morphometrics (GM) to mandibular teeth and metapodials, two skeletal elements commonly found in archaeological collections and known for their diagnostic properties using traditional morphometric methods. We registered a statistically representative set of 2D and 3D coordinates on mandibular teeth (P3, P4, M1, and M2) and metapodials of 92 domestic horses (Equus caballus Linnaeus, 1758), 70 domestic donkeys (Equus asinus Linnaeus, 1758), 30 hybrids, and 63 Asiatic wild asses (Equus hemionus Pallas, 1775). Taxonomic classification of these 255 specimens considered both shape and form, applying linear discriminant analysis, k‐nearest neighbors algorithm, and artificial neural networks to seven combinations of taxa. We obtained correct classifications in over 87% and 80%, respectively, of the premolars and molars and in over 93% and 89%, respectively, of the metacarpals and metatarsals. This modern dataset was then used to classify equid specimens from three archaeological sites in the Middle East already analyzed morphologically. Taking into account the past zoogeography of wild equids and the historical distribution of their domesticated descendants and hybrids, the GM approach presented in this study offers the possibility to morphologically classify archaeological equids with far greater certainty than has been the case so far.

Describing whisker morphology of the Carnivora.

One of the largest ecological transitions in carnivoran evolution was the shift from terrestrial to aquatic lifestyles, which has driven morphological diversity in skulls and other skeletal structures. In this paper, we investigate the association between those lifestyles and whisker morphology. However, comparing whisker morphology over a range of species is challenging since the number of whiskers and their positions on the mystacial pads vary between species. Also, each whisker will be at a different stage of growth and may have incurred damage due to wear and tear. Identifying a way to easily capture whisker morphology in a small number of whisker samples would be beneficial. Here, we describe individual and species variation in whisker morphology from two-dimensional scans in red fox, European otter and grey seal. A comparison of long, caudal whiskers shows inter-species differences most clearly. We go on to describe global whisker shape in 24 species of carnivorans, using linear approximations of curvature and taper, as well as traditional morphometric methods. We also qualitatively examine surface texture, or the presence of scales, using scanning electron micrographs. We show that gross whisker shape is highly conserved, with whisker curvature and taper obeying simple linear relationships with length. However, measures of whisker base radius, length, and maybe even curvature, can vary between species and substrate preferences. Specifically, the aquatic species in our sample have thicker, shorter whiskers that are smoother, with less scales present than those of terrestrial species. We suggest that these thicker whiskers may be stiffer and able to maintain their shape and position during underwater sensing, but being stiffer may also increase wear.

Analysis of the accuracy of computer‐assisted DCIA flap mandibular reconstruction applying a novel approach based on geometric morphometrics

This study evaluated the accuracy of computer-assisted surgery (CAS)-driven DCIA (deep circumflex iliac artery) flap mandibular reconstruction by traditional morphometric methods and geometric morphometric methods (GMM). Reconstruction accuracy was evaluated by measuring distances and angles between bilateral anatomical landmarks. Additionally, the average length of displacements vectors between landmarks was computed to evaluate factors assumed to influence reconstruction accuracy. Principal component analysis (PCA) was applied to unveil main modes of dislocation. High reconstruction accuracy could be demonstrated for a sample consisting of 26 patients. The effect of the number of segments and length of defect on reconstruction accuracy were close to the commonly used significance threshold (p=0.062/0.060). PCA demonstrated displacement to result mainly from sagittal and transversal shifts. CAS is a viable approach to achieve high accuracy in mandibular reconstruction and GMM can facilitate the evaluation of factors influencing reconstruction accuracy and unveil main modes of dislocation in this context.

Cytoarchitecture of Cerebellar Cortex: Fractal Analysis as a Method for Quantitative Studies

In this study we aimed to assess the possibility of fractal analysis utilization for the quantitative studies of cytoarchitecture in neuromorphology, namely in the studies of cerebellar cortex. We have chosen box counting method for fractal analysis. As an object of study we have chosen granule cell layer of cerebellar cortex. To estimate the informativeness of fractal analysis in the studies of cytoarchitecture and to assess the impact of the influencing factors (cell size, cell density or cell number, and pattern of cell distribution) we created artificial models of granule cells composition in the cerebellar cortex. We submit a proposition to consider the cell clusters and their assemblages as a whole entity. The cytoarchitecture as a whole entity exhibits some fractal properties: self-similarity of different scales, irregularity of the spatial configuration. Fractal dimension is the measure of space filling degree, so the fractal dimension measured in cellular groups characterizes space filling degree of cell assemblages. We revealed that the space filling degree depends on cell size, cell density (cell number) and pattern of cell distribution and clusterization. Increase in cell size or/and cell density (cell number) results in the increase in Fractal dimension values. Fractal dimension values are higher when cells are distributed evenly than when cells form the clusters. While the size and density (relative number) of cells can be estimated using traditional morphometric methods, the pattern of cell arrangement is mainly qualitative, and the fractal analysis allows to quantitatively and comprehensively assessing the cytoarchitecture of brain cortex.

Development of computer program for automatic X-ray analysis of quality of vegetable seeds

Traditional morphometric methods of seed quality analysis, although they are accurate, are less informative, labor-intensive and long-term in execution. In modern conditions, in seed science and seed control, the use of more informative and high-speed instrumental methods is required. The method of microfocus X-ray of seeds is one of them, it allows you to visualize the internal structure of seeds. In the joint work of employees of the Federal Scientific Vegetable Center, Agrophysical Research Institute and St. Petersburg State Electrotechnical University, Research Institute for Storage Problems of "Rosrezerv", a method of X-ray analysis of the quality of vegetable seeds was developed and tested. Currently, programming, automation of this method is underway. The method of digital analysis of X-ray images in automatic mode comes as a replacement for the previously applied visual analysis of seed radiographs. A modernized software and hardware complex was developed and tested, a program algorithm was compiled, consisting of several stages. As a result, the quality analysis of seeds is significantly accelerated by visualizing their internal structure. The newly developed computer program "Sortsemkontrol-2" recognizes seeds according to the following qualitative indicators: full-value, underdevelopment, undevelopment, monstrous. The analysis results are automatically reported as a log. The fractional analysis of the seed batch is also carried out, the dimensional characteristic of each fraction is given, according to the two largest adjacent fractions, the equalization of the seed batch is determined. Fractional analysis of a batch of seeds is of great practical importance for pre-production of seeds. In the future, the application of the computer program "Sortsemkontrol-2" will provide an accelerated, at the same time informative analysis of the quality of seeds, which is very important in the conditions of commercialization of seed turnover.

Fractal dimension of external linear contour of human cerebellum (magnetic resonance imaging study)

Fractal analysis is a method of mathematical analysis, which provides quantitative assessment of the spatial configuration complexity of the anatomical structures and may be used as a morphometric method. The purpose of the study was to determine the values of the fractal dimension of the outer linear contour of human cerebellum by studying the magnetic resonance images of the brain using the authors’ modification of the caliper method and compare to the values determined using the box counting method. Brain magnetic resonance images of 30 relatively healthy persons aged 18-30 years (15 men and 15 women) were used in the study. T2-weighted digital magnetic resonance images were studied. The midsagittal MR sections of the cerebellar vermis were investigated. The caliper method in the author’s modification was used for fractal analysis. The average value of the fractal dimension of the linear contour of the cerebellum, determined using the caliper method, was 1.513±0.008 (1.432÷1.600). The average value of the fractal dimension of the linear contour of the cerebellum, determined using the box counting method, was 1.530±0.010 (1.427÷1.647). The average value of the fractal dimension of the cerebellar tissue as a whole, determined using the box counting method, was 1.760±0.006 (1.674÷1.837). The values of the fractal dimension of the outer linear contour of the cerebellum, determined using the caliper method and the box counting method were not statistically significantly different. Therefore, both methods can be used for fractal analysis of the linear contour of the cerebellum. Fractal analysis of the outer linear contour of the cerebellum allows to quantify the complexity of the spatial configuration of the outer surface of the cerebellum, which is difficult to estimate using traditional morphometric methods. The data obtained from this study and the methodology of the caliper method of fractal analysis in the author’s modification can be used for morphometric investigations of the human cerebellum in morphological studies, as well as in assessment of cerebellar MR images for diagnostic purposes.

Bones of Contention: Reflections on Osteoarchaeology and the Baltic Region

During the last decade, some of the most significant archaeological interpretations included the integrated use of scientific methods, including osteoarchaeology. The identification, analysis and interpretation of human and animal remains from archaeological sites has been developing along increasingly different trajectories, due to the different aspects of daily life the bones of animals and humans illustrate. This paper is a review of the position osteoarchaeological research has achieved since the 1960s, through the example of its beginnings in the mid-20th century in Sweden. Similarities and differences between the histories, contents of and directions in human and animal osteoarchaeology are reviewed, revealing some controversies in the ways the results of the discipline have been embraced by the broader archaeological community. Similarly to archaeological research, increasingly complex analytical methods help refining results obtained by traditional morphometric methods applied to bones. This trend will continue in the foreseeable future: scientific methods will keep on contributing to valuable insights into past societies. Special sections in the paper are devoted to the possibilities of disseminating the results of osteoarchaeology through formal and informal networks such as publications, teaching and conferences within the context of the Baltic region through the example of archaeozoological research.

Body shape variation of Garra rufa (Heckel) (Teleostei: Cyprinidae) using geometric and morphometric techniques

Organisms can adapt to habitat conditions that ensure their survival. Habitat separation can lead to different populations of body shape during the phenotypic plasticity process. Both traditional and modern (geometric) morphology are being used in fish population studies. In this study, the body shape differences between Garra rufa (Heckel) populations captured in the Jarrahi River (from the Tigris Basin) were investigated using traditional and geometric morphometric methods. The samples were captured from the Rostam Abad, Aghajari and Behbahan tributaries and transferred to the laboratory. For the traditional morphometric analysis, 10 meristic characters and 19 morphometric characters were measured. Geometric morphological information was extracted using 13 landmark points on left side photographs of individual fish. According to the results of the traditional morphometric analysis, there were differences between the three populations in meristic (lateral line scales, predorsal scales, circamucaudal scales) and morphometric (14 of 19 characters) traits. In the geometric morphometric analysis, the major part of the shape variation is due to landmark points in the head region and the dorsal fin base, with the anal fin and caudal peduncle being the most conservative body regions. The populations had significant differences in body shape with populations from Aghajari and Behbahan tributaries being most similar and the Rostam Abad population was different from the two other populations.

Abstract P1-06-05: Image driven biophysical mathematical modeling of multicellular breast tumor spheroids

Abstract Introduction: Conventional 2D monolayer cell culture methods have distinct weaknesses in mimicking in vivo tumors as they ignore major phenotypic physical tumor microenvironment (TME) factors. 3D multicellular tumor spheroid (MTS) systems have been developed to study cancer cell growth in the presence of such TME factors, including cell-cell and cell-extracellular matrix (ECM) mechanical interactions. However, the development of analysis methodologies for these complex culture systems has considerably lagged. We hypothesize that a coupled experimental-computational framework using a microscopy image-driven biophysical mathematical model of MTS systems can accurately estimate phenotypic growth and biophysical TME properties, revealing significantly more mechanistic information than traditional morphometric analysis methods. Materials and Methods: MDA-MB-231 triple-negative breast cancer cells were used to generate spheroids. A single 3D MTS embedded in Collagen I ECM was used as a 3D culture tumor model system as they exhibit cell-cell and cell-ECM interactions that mimic in vivo tumors. Fluorescent fiducial microspheres were placed in the ECM to track displacement induced by the MTS. Time-lapse fluorescence microscopy images were taken of the MTS and microspheres for 72 hours on an automated fluorescent microscope every 12-hours. Images were compiled using a customized fully-automated tiling/stitching/image processing software in MATLAB. Time-lapse images of the MTS and microspheres are used in conjunction with subsequent mathematical modeling analysis for biophysical parameter estimation. We assess MTS using a mathematical model based on two coupled partial differential equations describing growth/motility and mechanical equilibrium in response to cellular-induced forces. Parameters describing cell proliferation rate (k), cell diffusion (D), and cellular mechanical forces (λ) are estimated based on fitting acquired microscopy images to the model via an iterative least-squares parameter estimation. Experiments and model-based analyses were performed in triplicate to define the reproducibility of biophysical parameter estimation. Results and Discussion: In this preliminary study, our modeling framework is able to estimate biophysical parameters of cell diffusion, proliferation rate, and cellular mechanical force in a 3D breast cancer cell culture system of invading MTS embedded in ECM with coefficients of variation across all parameters less than 15% on average. The model predictions accurately represent changes in cellular density and ECM deformation induced by cellular traction forces throughout the observed time series, demonstrating that this model is capable of representing MTS/ECM growth behavior and parameterizing the driving biophysical properties. Conclusions: These results indicate that our imaging-driven mathematical modeling framework for estimating biophysical model parameters has potential to reliably characterize 3D MTS growth and invasion. With reproducibility established, we plan to extend the method to investigate these phenotypic biophysical TME properties in a range of culture and treatment condition interventions. These biophysical properties could be utilized in developing anti-neoplastic drug sensitivity assays to improve cancer therapy by enabling patient-specific estimation/prediction of response to agents and dosing conditions. Acknowledgements: NIH-NCI K25CA204599 and P30CA012197 Citation Format: Haley Brooke Johnson, Emily E. Fannin, Alexandra Thomas, Jared A Weis. Image driven biophysical mathematical modeling of multicellular breast tumor spheroids [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-06-05.

Diversification and evolutionary history of brush-tailed mice, Calomyscidae (Rodentia), in southwestern Asia

Brush-tailed mice, family Calomyscidae, are endemic to southwestern Asia and are represented by eight described species and three additional lineages. Although this family includes only a single genus, Calomyscus, in which several molecular phylogenies were recovered as a monophyletic clade, no updated evolutionary survey has been undertaken until now. We present a time-calibrated molecular phylogenetic tree of members of this genus using mitochondrial and nuclear markers. According to our results, divergence of calomyscid species occurred between 5.85 and 3.35 Mya during the Late Miocene and Pliocene. It seems that the species that occur in the eastern part of the range of the family diverged earlier (highest posterior density (HPD) 3.95–7.28 Mya) from congeners than those from the western part (HPD 2.18–4.24 Mya). Furthermore, we provide new insights on a poorly known species, C. grandis, endemic to the Elburz Mountains, including its phylogeny, morphology (geometric morphometric, karyology, and traditional morphometric methods), and distribution. Our findings show greater haplotype diversity than previously reported and extend the known range of C. grandis in northern Iran. Molecular data detects the existence of an additional distinct lineage from the Zagros Mountains, which appears to be differentiated from other lineages of Calomyscus at levels observed between species. Morphologically, compared to other species, the new lineage is the largest brush-tailed mouse and shows a number of remarkable differences in cranial features (e.g., widest cranium and highest mandible) with chromosomal component 2n = 44 and FNa = 62. Higher species diversity of calomyscids around the Iranian Plateau may be the result of geological events and the subsequent aridification during the Pliocene. The Lut Desert and the Zagros Mountains provided barriers and refugal habitat, respectively, that likely contributed to speciation events within the genus. Additional sampling may discover more distinct lineages in the Zagros Mountains or Anatolia and the eastern Mediterranean region.

Comparative Morphometric Studies of the Cranium in the Three Types of Birds with Different Feeding Behaviors

The present work was particularly designed to study the comparative anatomy of the skull of three different feeding Aves species inhibiting in Egypt. This study demonstrates that both size and shape are important components in the morphological differentiation of the skulls of carnivorous Kingfisher (Halcyon smyrnensis), insectivore Hoopoes (Upupa epops) and Omnivores Chicken (Gallus gallus domesticus) which clarify the relationship between size, shape of the skull and the type of feeding behavior. This paper presents a morphometric analysis of Kingfisher, Hoopoes and chicken skulls. Analyses are performed using traditional analytic and morphometric methods.

Geometric vs. traditional morphometric methods for exploring morphological variation of tadpoles at early developmental stages

Abstract We conducted a comparative (2D landmark-based geometric and traditional) morphometric analysis on tadpoles at early developmental stages. Two species of brown frog (Rana dalmatina and R. temporaria) and the common toad (Bufo bufo) were involved, all raised in the laboratory from fertilized eggs collected in their natural habitat. Taxonomic identification was confirmed by the DNA barcoding method with the 16S rRNA sequence as the gene marker. Interested to compare the methodologies for quantification and description of morphological differences among tadpoles of mentioned species, we aimed to: 1) calculate interspecies genetic distances as the most relevant measurement for species differentiation, 2) determine and describe size and shape variation, 3) identify relationships among the analyzed species at the morphological level and 4) assess their classification accuracy. Within the framework of the specified aims, both methodologies produced very similar results, i.e., the smallest divergence was between R. dalmatina and R. temporaria, while the most discriminative were B. bufo and R. temporaria. However, we observed subtle shape variation of the distal region of the tail that was detected only by the geometric morphometrics. Our findings support the following. Geometric morphometric method captures more subtle shape differences that were unable to be recovered from linear measurements. It performs slightly better in classification rate. Although it was not quantified, it stands to reason that there is no difference in time investment between the two approaches. Geometric morphometrics provides more information that can be leveraged to answer further questions and it has a clear advantage in visualizing.

Mandibular shape in farmed Arctic foxes (Vulpes lagopus) exposed to persistent organic pollutants

We investigated if dietary exposure to persistent organic pollutants (POPs) affect mandibular asymmetry and periodontal disease in paired male-siblings of Arctic foxes (Vulpes lagopus). During ontogeny, one group of siblings was exposed to the complexed POP mixture in naturally contaminated minke whale (Balaenoptere acutorostarta) blubber (n = 10), while another group was given wet feed based on pig (Sus scrofa) fat as a control (n = 11). The ∑POP concentrations were 802 ng/g ww in the whale-based feed compared to 24 ng/g ww in the control diet. We conducted a two-dimensional geometric morphometric (GM) analysis of mandibular shape and asymmetry in the foxes and compared the two groups. The analyses showed that directional asymmetry was higher than fluctuating asymmetry in both groups and that mandibular shape differed significantly between the exposed and control group based on discriminant function analysis (T2 = 58.52, p = 0.04, 1000 permutations). We also found a non-significantly higher incidence of periodontal disease (two-way ANOVA: p = 0.43) and greater severity of sub-canine alveolar bone deterioration similar to periodontitis (two-way ANOVA: p = 0.3) in the POP-exposed group. Based on these results, it is possible that dietary exposure to a complexed POP mixture lead to changes in jaw morphology in Arctic foxes. This study suggests that extrinsic factors, such as dietary exposure to POPs, may affect mandibular shape and health in a way that could be harmful to wild Arctic populations. Therefore, further studies using GM analysis as an alternative to traditional morphometric methods should be conducted for wild Arctic fox populations exposed to environmental contaminants.

Analysis of shape variability and life history strategies of Illex argentinus in the northern extreme of species distribution as a tool to differentiate spawning groups

ABSTRACTThis study aimed to differentiate local and migratory spawning groups of the shortfin squid Illex argentinus caught in Brazilian waters using geometric and traditional morphometric methods and size-selective processes. The back-calculated length distributions reconstructed from daily growth increments deposited in the gladius allowed the identification of size-selective processes that may be related to different life history strategies. Landmark analysis on body shape (geometric morphometric) revealed that spawning groups presented significant ontogenetic variations in terms of body outline. In addition, traditional morphometric methods, based on multivariate analysis, associated juveniles of the expected migratory group (large size) and differentiated them from the local group individuals (small size). The changes in form, probably linked to the environmental gradients experienced by individuals throughout ontogeny, were interpreted as adaptations to improve swimming capacity. Migrant individuals have being differentiated from the smaller sizes group by body characteristics (broad fins, elongated and thicker mantle), which may increase the ability to perform long migrations.

The costal remains of the El Sidrón Neanderthal site (Asturias, northern Spain) and their importance for understanding Neanderthal thorax morphology

The study of the Neanderthal thorax has attracted the attention of the scientific community for more than a century. It is agreed that Neanderthals have a more capacious thorax than modern humans, but whether this was caused by a medio-lateral or an antero-posterior expansion of the thorax is still debated, and is key to understanding breathing biomechanics and body shape in Neanderthals. The fragile nature of ribs, the metameric structure of the thorax and difficulties in quantifying thorax morphology all contribute to uncertainty regarding precise aspects of Neanderthal thoracic shape. The El Sidrón site has yielded costal remains from the upper to the lower thorax, as well as several proximal rib ends (frequently missing in the Neanderthal record), which help to shed light on Neanderthal thorax shape. We compared the El Sidrón costal elements with ribs from recent modern humans as well as with fossil modern humans and other Neanderthals through traditional morphometric methods and 3D geometric morphometrics, combined with missing data estimation and virtual reconstruction (at the 1st, 5th and 11th costal levels). Our results show that Neanderthals have larger rib heads and articular tubercles than their modern human counterparts. Neanderthal 1st ribs are smaller than in modern humans, whereas 5th and 11th ribs are considerably larger. When we articulated mean ribs (size and shape) with their corresponding vertebral elements, we observed that compared to modern humans the Neanderthal thorax is medio-laterally expanded at every level, especially at T5 and T11. Therefore, in the light of evidence from the El Sidrón costal remains, we hypothesize that the volumetric expansion of the Neanderthal thorax proposed by previous authors would mainly be produced by a medio-lateral expansion of the thorax.

Morphometrics of Leptoplastides marianus (Hoek) (Trilobita, Olenidae) from the Tremadocian of north-western Argentina: taxonomic implications

Morphometrics can be an important tool in systematic studies, providing taxonomists with strong elements of quantification and formal hypothesis testing. Here, these tools are tested for the trilobite Leptoplastides marianus (Hoek) which was originally described on the basis of three deformed specimens from west Tarija, Bolivia. Following the conclusions of Harrington & Leanza, a wide range of morphological variation is accepted for this species, and the name was applied to a large number of specimens from north-western Argentina. Based on specimens collected from the quebrada Moya (Huacalera, Jujuy), as well as on material in the Harrington & Leanza collections in the University of Buenos Aires, traditional morphometric and geometric morphometric methods were used to evaluate the variation of the cranidial shape of L. marianus sensu Harrington & Leanza. The results allow discrimination between two clearly different morphotypes. The name L. marianus should be restricted to the type specimens, given the deformation of these materials. In addition, L. argentinensis and L. granulosus are both valid names for the two morphotypes recognized in the present paper.

Separating Sheep (Ovis aries L.) and Goats (Capra hircus L.) Using Geometric Morphometric Methods: An Investigation of Astragalus Morphology from Late and Final Bronze Age Central Asian Contexts

AbstractMany qualitative and quantitative methods for the separation of sheep and goat bones are based upon Middle Eastern, Mediterranean and European specimens. However, these methods may not be as applicable in other geographical contexts due to regional morphological variation. In order to address this, both traditional and geometric morphometric methods were applied to sheep, (Ovis aries L.) and goat (Capra hircus L.) astragali from archaeological sites from Kazakhstan dating to the Late and Final Bronze Age (1900–900 bce). This exploratory research confirmed that qualitative features remained useful for distinguishing between species, while traditional morphometric methods were unable to conclusively support the field identification of species. Geometric morphometric methods found significant morphological differences between species and confirmed group membership while exploring specific qualitative features that were effective in distinguishing between sheep and goat in Central Asian contexts. Copyright © 2016 John Wiley & Sons, Ltd.