143 research outputs found
Comparaison des ichnopopulations des Grands Causses (Sud de la France) et du Veillon (Vendée)
From descriptive statistic method concerning length (L), width (W) and L/W, it is suggested that Grallator variabilis samples from Vendée (Le Veillon) and Grands Causses belong to the same ichnospecies. Also, by this way, G. maximus of Hettangian of Vendée could be synonym of G. minusculus from USA Hettangian
Les sites à traces de pas de vertébrés du Trias à l'Hettangien : contenu et interprétation
Footprints are numerous in France where they found from Carboniferous to Quaternary levels. Those of Middle Triassic (Anisian-Ladinian) are especialy interesting because they are tridactyl footprints made probably by first dinosaurs. First skelettons are known from Upper Ladinian / lower Carnian
Estudio del Rhynchosauroides santanderiensis, n. sp., y otras nuevas huellas de pisadas en el Trias de Santander, con notas sobre el ambiente paleográfico
Procedentes del TrÃas del área de Puentenansa (Santander) se describen cuatro tipos de huellas de pisadas de reptiles de pequeño tamaño. Ninguno de los tipos se conocÃa anteriormente, pero sólo se ha dado nombre a uno de ellos (Rhynchosauroides santanderiensis, n.sp.).Se expone también, realizado a partir de datos petrológicos, un esbozo de las condiciones existentes en el área en la época en que vivieron los autores de las pistas. Este esbozo coincide con las conclusiones que pueden deducirse de la existencia y caracterÃsticas de las huellas (zona marginal respecto al conjunto de la cuenca, sometida a inundaciones periódicas)
Signification des aires à empreintes de pas de vertébrés des Grands Causses (Biologie et Physiologie)
Numerous footprints areas has been found, since 1962, in Permian, Triassic and Hettango-Sinemurian. All show precised oriented trackways. So that they were undestood like walking ways but their precise meaning is still enigmatic
Estudio del Rhynchosauroides santanderiensis, n. sp., y otras nuevas huellas de pisadas en el Trias de Santander, con notas sobre el ambiente paleográfico
Procedentes del TrÃas del área de Puentenansa (Santander) se describen cuatro tipos de huellas de pisadas de reptiles de pequeño tamaño. Ninguno de los tipos se conocÃa anteriormente, pero sólo se ha dado nombre a uno de ellos (Rhynchosauroides santanderiensis, n.sp.).Se expone también, realizado a partir de datos petrológicos, un esbozo de las condiciones existentes en el área en la época en que vivieron los autores de las pistas. Este esbozo coincide con las conclusiones que pueden deducirse de la existencia y caracterÃsticas de las huellas (zona marginal respecto al conjunto de la cuenca, sometida a inundaciones periódicas)
The FRALIT teledetection program, using the ERTS-A satellite, for the oceanic littoral of France
There are no author-identified significant results in this report. The French Atlantic Littoral program, utilizing data from the ERTS-1 satellite, is considered. It involves teledetection of the French shoreline along the Atlantic Ocean and English Channel. A description is given of the ERTS-1 orbit and the satellite itself, including the attitude control system, and the data acquisition and transmission equipment. The geographic extent of the area covered by the program is delineated and the subjects studied are enumerated. These include the geomorphology, pedology, hydrology, and vegetation of the maritime marshes; sedimentology, morphology, and hydrology of the intertidal zones; and transport of material in suspension to the mouths of the Seine, the Loire, and the Gironde as a part of the coastal waters study
Mise en œuvre du MDE pour la conception de systèmes embarqués: premiers résultats et perspectives du projet Lambda
National audienceDémarré en juin 2008, Lambda est un projet de recherche collaboratif rassemblant 14 partenaires industriels, PME et académiques. Le projet se focalise sur la modélisation de plateformes d'exécutions dans le contexte de la conception de systèmes embarqués. Il vise des assemblages complexes de composants sur étagère, dans le cadre de cas de test représentatifs des problèmes actuels rencontrés par les intégrateurs système (contrôle de latences réseau, configuration des tâches et ordonnancement). Un premier objectif est de démontrer la faisabilité technique, ainsi que l'intérêt, de la modélisation de plateformes, comme un moyen de valider le déploiement et la configuration des composants du système. Un second objectif vise à réconcilier les standards appropriés (SysML, MARTE, AADL, IP-XACT) avec les standards de facto (déjà implémentés dans des outils d'analyse ou de simulation largement répandus). Un an et demi après son démarrage, Lambda fourni déjà des résultats visibles. Une utilisation intensive de SysML/MARTE dans des expérimentations de modélisation a permis d'identifier des bonnes pratiques, ainsi qu'un sous-ensemble de MARTE applicable dans un contexte d'ingénierie système. Les problématiques clés liées au déploiement massif du MDE dans l'industrie (MCO des ateliers de modélisation, passage à l'échelle) ont commencé à être adressées. Des actions concrètes d'alignement des standards (SysML, MARTE, AADL) et la convergence entre standards et outils commerciaux conduit à un panorama plus clair dans ce domaine. L'article décrit le contexte technique ainsi que les problématiques adressées par le projet Lambda. Après avoir présenté les objectifs du projet et le partenariat, il détaille les travaux en cours et présente une vue d'ensemble des premiers résultats. En conclusion, l'article évoque le travail restant dans le projet, ainsi que les perspectives pour les partenaires impliqués
Stat-tracks and mediotypes: powerful tools for modern ichnology based on 3D models.
Vertebrate tracks are subject to a wide distribution of morphological types. A single trackmaker may be associated with a range of tracks reflecting individual pedal anatomy and behavioural kinematics mediated through substrate properties which may vary both in space and time. Accordingly, the same trackmaker can leave substantially different morphotypes something which must be considered in creating ichnotaxa. In modern practice this is often captured by the collection of a series of 3D track models. We introduce two concepts to help integrate these 3D models into ichnological analysis procedures. The mediotype is based on the idea of using statistically-generated three-dimensional track models (median or mean) of the type specimens to create a composite track to support formal recognition of a ichno type. A representative track (mean and/or median) is created from a set of individual reference tracks or from multiple examples from one or more trackways. In contrast, stat-tracks refer to other digitally generated tracks which may explore variance. For example, they are useful in: understanding the preservation variability of a given track sample; identifying characteristics or unusual track features; or simply as a quantitative comparison tool. Both concepts assist in making ichnotaxonomical interpretations and we argue that they should become part of the standard procedure when instituting new ichnotaxa. As three-dimensional models start to become a standard in publications on vertebrate ichnology, the mediotype and stat-track concepts have the potential to help guiding a revolution in the study of vertebrate ichnology and ichnotaxonomy
Bird-Like Anatomy, Posture, and Behavior Revealed by an Early Jurassic Theropod Dinosaur Resting Trace
BACKGROUND: Fossil tracks made by non-avian theropod dinosaurs commonly reflect the habitual bipedal stance retained in living birds. Only rarely-captured behaviors, such as crouching, might create impressions made by the hands. Such tracks provide valuable information concerning the often poorly understood functional morphology of the early theropod forelimb. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a well-preserved theropod trackway in a Lower Jurassic ( approximately 198 million-year-old) lacustrine beach sandstone in the Whitmore Point Member of the Moenave Formation in southwestern Utah. The trackway consists of prints of typical morphology, intermittent tail drags and, unusually, traces made by the animal resting on the substrate in a posture very similar to modern birds. The resting trace includes symmetrical pes impressions and well-defined impressions made by both hands, the tail, and the ischial callosity. CONCLUSIONS/SIGNIFICANCE: The manus impressions corroborate that early theropods, like later birds, held their palms facing medially, in contrast to manus prints previously attributed to theropods that have forward-pointing digits. Both the symmetrical resting posture and the medially-facing palms therefore evolved by the Early Jurassic, much earlier in the theropod lineage than previously recognized, and may characterize all theropods
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