Search results for "morphometric"

Differences in inner ear asymmetry levels between slow-moving and fast-moving primates

2021

International audience; The vestibular system of the inner ear, highly involved in maintaining balance during activities and positional behaviour of animals, has been deeply studied in order to link its morphology with the specific type of locomotion. Previous studies (e.g. Perier et al. 2016, Gonzales et al. 2018) have shown that, in primates, the amount of morphological variation is higher in slow-moving species than in fast-moving ones. These results indicate a lower selective pressure and a reduced functional demand for postural adjustments in the former group, and a higher selective pressure for balance and postural capabilities in the latter. In this study, we assessed if the differen…

Differentiation of

2019

Trichuris trichiura is a nematode considered as the whipworm present in humans and primates. The systematics of the genus Trichuris is complex. Morphological studies of Trichuris isolated from primates and humans conclude that the species infecting these hosts is the same. Furthermore, numerous molecular studies have been carried out so far to discriminate parasite species from humans and Non-Human Primates using molecular techniques, but these studies were not performed in combination with a parallel morphological study. The hypothesised existence of more species of Trichuris in primates opens the possibility to revise the zoonotic potential and host specificity of T. trichiura and other p…

ANALYSIS OF THE SEXUAL VARIABILITY IN THE SHELL OF THE SPANISH UPPER CRETACEOUS TURTLE DORTOKA VASCONICA (PAN-PLEURODIRA, DORTOKIDAE)

2021

The present study characterizes the morphological variability related to the sexual dimorphism in the shells of the Spanish Upper Cretaceous turtle  Dortoka vasconica . This study is based on the material from its type locality: Lano, Burgos. Two morphotypes were identified there based on the posterior plastral area as well as two for the anterior plastral lobe. However, a correlation with the previously indicated morphotypes could not be established due to the disarticulation of the specimens and the limited information available on the sexual dimorphism of Pleurodira. The morphological variability previously identified for  Dortoka vasconica  is analysed here through a quantitative approa…

Ecomorphological variation within and among the two marine species of genus Salaria: Salaria basilisca and Salaria pavo (Perciformes: Blenniidae)

2022

In order to highlight the variation of the form due to the presence of different ecological factors, we investigated in this paper the morphological variation between and within the two marine species Salaria basilisca and S. pavo. This study was based on two approaches, the Truss network and the geometric morphometric and involved specimens of both species divided into marine and lagoon samples. The two approaches yielded complementary results showing clear morphological discrimination of the two species Thus, S. basilisca is distinguished by a higher depth and length as well as a higher head with a compressed snout compared to S. pavo which has a shortened body, a lower head and a slightl…

GIS-MORPHOMETRIC ANALYSIS OF BADLANDS IN SICILY (ITALY)

2012

Sicily is affected by severe erosion processes, locally causing large volumes of soil loss and high denudation rates. The effects of intense water erosion phenomena are testified by the occurrence of badlands that constitute a common landscape particularly in the central and southern areas of the Island, where slopes are frequently underlain by clay-rich deposits. This paper presents the first results of an investigation carried out in a badlands site located in the head sector of the Imera Meridionale river basin, where geometry of several erosion channels has been characterized. Since length of linear erosion landforms such as rills, ephemeral gullies and permanent gullies, has been prove…

Shape change during the growth of sharpsnout seabream reared under different conditions in a fish farm of the southern Tyrrhenian Sea

2003

Morphometric diversity of the mussel Brachidontes pharaonis in different coastal environments

2010

In the debate on how and why biodiversity evolves spatially and temporally and in an attempt to assess the further effects of anthropogenic activities, the ability of marine invertebrate to express a large spectrum of phenotypical plasticity can have a central role. The ability of a single genotype to produce more than one alternative form of morphology and/or physiological state should be larger in species living in highly changing waters like shallow habitats. Invertebrates, there, usually experience ample changes of temperature and food availability on annual, seasonal, diurnal and hourly bases which are the two main drivers leading the life histories of these organisms. In such circumst…

3D Geometric morphometrics to investigate Cercopithecini evolution

2014

3D Geometric Morphometrics has been used on a preliminary dataset of 163 crania and 148 mandibles of primates. We sampled 27 species from Cercopithecidae and Hominidae, collected in 7 different museums. Our sampling campaign was carried on with the use of a 3D-digitizer Microscribe G2X and the data were processed through the software Morphologika. The preliminary PCA analyses on crania highlight the presence of two different groups, which distinguish some Chlorocebus and Unknown Cercopithecus samples from all the others. Regarding on mandibular shape analyses, we found a light cluster of Cercopithecus samples. The “Sex” variable does not affect the reliability of the analysis, probably beca…

Long-term earthquake potential of active faults by using coastal and off-shore geological and morphological indicators

2017

Seismogenic fault models and active deformation ones coupled with models of both earthquake rate and earthquake probability were recently used in a time-independent modelling. The integration of models allows to estimates the magnitude, location, and likelihood of potentially damaging earthquake ruptures in regions with high natural seismic hazard. Improvements of these models imply the recognition of the spatial geometry of the larger, active faults, deemed to be the source of the most damaging future earthquakes. However, identifying active faults and calculating their geologic slip rates for deriving earthquake rates are not easy tasks in regions inaccessible to direct field studies like…

Neotectonic uplift and tilting of crustal blocks in Northern Sicily

2009

La Sicilia settentrionale è caratterizzata da un’intensa attività sismica che è espressione di deformazioni attive. In questo settore dell’Isola affiora il nucleo della catena neogenica delle Magrebidi occidentali, che è sottoposto ad intenso sollevamento durante il Plio-Pleistocene. Le deformazioni più recenti sono, in gran parte, rappresentate da sistemi di faglie estensionali e trascorrenti. Il tasso di sollevamento non è uniforme, così come suggerisce la differente elevazione dei depositi di questo periodo. Essi affiorano lungo il settore costiero settentrionale e la loro quota decresce complessivamente dall’estremità nord-est a quella nord-ovest della Sicilia. Le deformazioni più recen…