Search results for "Geometric morphometrics"

Association between ribs shape and pulmonary function in patients with Osteogenesis Imperfecta

2019

Graphical abstract

Morphological variability of Upper Paleolithic and Mesolithic skulls from Sicily

2020

Scenarios for the dispersal of Homo sapiens in Southern Europe and in the Mediterranean basin have been uncertain, given the scarceness of osteological samples and the simplicity of the proposed archaeologically-based settlement hypotheses. According to available data, the first anatomically modern humans entered Sicily during the Late Pleistocene, coming from the Italian peninsula. A presumably small Late Epigravettian population colonised coastal sites. Later, North-Western archaeological horizons gave hospitality to a significant Mesolithic expansion. In order to verify a hypothesis of continuity in the peopling of the island, we analyzed Sicilian skulls from the Late Epigravettian site …

Shape change in the atlas with congenital midline non-union of its posterior arch: a morphometric geometric study.

2017

Background Context The congenital midline non-union of the posterior arch of the atlas is a developmental variant present at a frequency ranging from 0.7% to 3.9%. Most of the reported cases correspond to incidental findings during routine medical examination. In cases of posterior non-union, hypertrophy of the anterior arch and cortical bone thickening of the posterior arches have been observed and interpreted as adaptive responses of the atlas to increased mechanical stress. Purpose We sought to determine if the congenital non-union of the posterior arch results in a change in the shape of the atlas. Study Design/Setting This study is an analysis of the first cervical vertebrae from osteo…

Quantitative trait loci affecting the 3D skull shape and size in mouse and prioritization of candidate genes in-silico.

2015

13 pages; International audience; We describe the first application of high-resolution 3D micro-computed tomography, together with 3D landmarks and geometric morphometrics, to map QTL responsible for variation in skull shape and size using a backcross between C57BL/6J and A/J inbred strains. Using 433 animals, 53 3D landmarks, and 882 SNPs from autosomes, we identified seven QTL responsible for the skull size (SCS.qtl) and 30 QTL responsible for the skull shape (SSH.qtl). Size, sex, and direction-of-cross were all significant factors and included in the analysis as covariates. All autosomes harbored at least one SSH.qtl, sometimes up to three. Effect sizes of SSH.qtl appeared to be small, r…

Environmental and ontogenetic constraints on developmental stability in the spatangoid sea urchin Echinocardium (Echinoidea).

2006

13 pages; International audience; Spatangoid irregular sea urchins are detritivorous benthic organisms particularly prone to variations of environment, and their mode of growth and plate morphology make them an appropriate model to assess the effects of environmental variations. Two populations of Echinocardium flavescens were sampled in two sites of the Norwegian coast characterized by contrasted environmental conditions. Different morphological descriptors (plate areas, interlandmarks distances, overall size, and shape of the posterior ambulacra) were used to appraise interindividual variations, and fluctuating asymmetry. The comparisons were carried out using classical fluctuating asymme…

Explorative 3D geometric morphometrics on crania and mandibles of Cercopithecini (1024 specimens)

2015

A dataset of crania and mandibles from Old World primates was investigated through the use of 3D Geometric Morphometrics. We focused the attention on the tribe Cercopithecini, sampling 1024 specimens preserved in 9 different museums and related to a total of 31 species. Other 102 specimens belonging to 10 species of the same family Cercopithecidae were added as outgroup. Our sampling campaign was carried on with a 3D-digitizer Microscribe G2X and the data were processed through the softwares Morphologika and MorphoJ. We conducted both PCA and CVA analyses to investigate the power of resolution of the morphometric method and to understand the role of a-priori groups in the discrimination of …

Ecomorphological inferences in early vertebrates: reconstructing

2017

Our knowledge about the body morphology of many extinct early vertebrates is very limited, especially in regard to their post-thoracic region. The prompt disarticulation of the dermo-skeletal elements due to taphonomic processes and the lack of a well-ossified endoskeleton in a large number of groups hinder the preservation of complete specimens. Previous reconstructions of most early vertebrates known from partial remains have been wholly based on phylogenetically closely related taxa. However, body design of fishes is determined, to a large extent, by their swimming mode and feeding niche, making it possible to recognise different morphological traits that have evolved several times in no…

L’IMPIEGO DELLA MORFOMETRIA GEOMETRICA E IL CONTRIBUTO DELLA CITOGENETICA NELLO STUDIO DELLA TRIBÙ CERCOPITHECINI (ORDINE PRIMATES)

The tribe Cercopithecini is a large and colourful taxon of African primates. Together with the tribe Papionini, it belongs to the subfamily Cercopithecinae (Gray, 1821). Despite several studies carried on the present species of Cercopithecini (guenons and sister genera), up to date a strong and clear systematics is missing. The evolutionary relationships inside the tribe are controversial, as are the numbers of genera and species. This lack prevents our full comprehension of the evolution of the tribe. We decided to investigate the tribe Cercopithecini through the use of two methodologies: geometric morphometrics and cytogenetics. The geometric morphometric survey was conducted on 1126 cran…

Species identification of the psammophilous tenebrionid beetles Phaleria acuminata Juster, 1852 and Phaleria bimaculata (Linnaeus, 1767) from central…

2013

Dominating global arid environments, from desert to coastal dunes, most Tenebrionidae are highly specific in their habitat preferences and display limited dispersal potential, thus exhibiting a remarkable degree of regional genetic and morphological differentiation. The tenebrionid genus Phaleria is speciose and widely distributed, with P. acuminata and P. bimaculata having a wide Mediterranean distribution, with numerous morphological differentiations at population level, often described as different taxa of doubtful taxonomical significance. In order to investigate the variability of the central Mediterranean populations of P. bimaculata and P. acuminata and to compare the results obtaine…

L'ornementation des bracelets de l'âge du Bronze européen : analyse descriptive et perspectives

2013

This paper discusses the ornamental patterns of metal bracelets worn on the arms and legs of people during the European Bronze Age. A method has been specially created to study geometric patterns. Some sets of metal bands (bracelets métalliques) of Bronze Age reach a high level of complexity due to the use of combined patterns in an overall structure. This paper deals with an experimental criterion concerning this phenomenon. The methodology, developed for the purpose i.e. the experimental criterion developed for the purpose of this study, was to extract geometric patterns from the original media. The principle is to release the geometrical compositions of the deformations induced by the mo…