7 research outputs found

    Données palynologiques nouvelles concernant l'Ordovicien et le Trias - Lias du Moyen-Atlas (Maroc)

    No full text
    New palynologie data about the Ordovician and the Trias-Lias of the Middle-Atlas (Morocco). Owing to the discovery of sporopollinic associations in the Middle Atlas basement, the Lower Ordovician (Arenigian - Llanvirnian) and Upper Ordovician (Caradocian) are identified in pelitic series of previously assumed Visean age. Moreover, other associations provide informations about the deposit conditions and ages of many sedimentary levels lying below, above, and between Upper Triassic basaltic lava flows.L'étude d'associations sporo-polliniques découvertes dans des formations non datées du Moyen-Atlas a permis : - l'identification de l'Ordovicien inférieur (Arénigien - Llanvirnien) et supérieur (Caradocien) dans des séries pélitiques antérieurement attribuées au Viséen ; - des indications concernant les conditions de dépôt et l'âge de plusieurs niveaux sédimentaires qui encadrent ou séparent les épanchements basaltiques de la période fini-triasique.Baudelot Sabine, Charriere André, Ouarhache Driss, Sabaoui Abdellah. Données palynologiques nouvelles concernant l'Ordovicien et le Trias - Lias du Moyen-Atlas (Maroc). In: Géologie Méditerranéenne. Tome 17, numéro 3-4, 1990. Le paleozoïque du Maroc. I – Cambrien – Dévonien (Paléontologie – Biostratigraphie) pp. 263-277

    Nouvelles datations micropaléontologiques et palynologiques dans le Viséen de la bordure nord occidentale du Causse moyen-atlasique (Maroc)

    No full text
    New micropaleontological and palynological datations in the Visean from the Northwestern margin of the Middle-Atlasic Plateau (Morocco). Visean outcrops located South of Fes (Morocco) yield almost complete biostratigraphical series, with abundant Foraminifera micro-fauna, calcareous Algae microflora and miospores. These microfossils and their illustration are the object of this notice. The different zones of Foraminifera from the Moroccan Visean and Early Serpukho-vian are identified. Upper Visean miospores are discovered. Detailed description of the outcrops is given. The main result concerns the post-Visean age, and not Tournaisian, of the Migoumess Formation.Les affleurements viséens au Sud de Fès (Maroc) livrent une série biostratigraphique à peu près complète qui a fourni d'intéressantes microfaunes de Foraminifères et microflores d'Algues calcaires et de miospores dont l'analyse et l'illustration font l'objet de cet article. Les différentes zones de Foraminifères du Viséen et de la base du Serpoukhovien marocains se retrouvent, ainsi que des miospores du Viséen supérieur. Une analyse détaillée des gisements est donnée ; un résultat notable est la confirmation d'un âge postérieur au Viséen et non tournaisien de la Formation de Migoumess.Ouarhache Driss, Baudelot Sabine, Charriere André, Perret Marie-France, Vachard Daniel. Nouvelles datations micropaléontologiques et palynologiques dans le Viséen de la bordure nord occidentale du Causse moyen-atlasique (Maroc). In: Géologie Méditerranéenne. Tome 18, numéro 1-2, 1991. Le paleozoïque du Maroc. II – Carbonifère – Permien (Paléontologie – Biostratigraphie – Aspects structuraux) pp. 43-59

    New Middle to ?Late Jurassic dinosaur tracksites in the Central High Atlas Mountains, Morocco

    Get PDF
    Besides bones, fossil tracks and trackways are important sources of knowledge about dinosaur palaeobiology. Here, we report three new tracksites from two different synclines in the Imilchil area, Central High Atlas, Morocco. The tracks and trackways are preserved in fluvial deposits in different levels of the Isli Formation (Early Bathonian–?Upper Jurassic), and contain impressions made by sauropods, theropods and ornithopods, as well as tracks that might represent bird-like non-avian theropod dinosaurs. In addition to traditional field measurements, three-dimensional digital models of the track sites were created using photogrammetry. These new tracksites add to the rich faunal ichnoassemblage already recorded from the High Atlas Mountains and North Africa, which is considerably richer than the contemporaneous body fossil record, and also provide new data on dinosaurs–substrate interactions

    Bizarre dermal armour suggests the first African ankylosaur

    Full text link
    Ankylosauria is a diverse clade of armoured dinosaurs whose members were important constituents of many Cretaceous faunas. Phylogenetic analyses imply that the clade diverged from its sister taxon, Stegosauria, during the late Early Jurassic, but the fossil records of both clades are sparse until the Late Jurassic (~150 million years ago). Moreover, Ankylosauria is almost entirely restricted to former Laurasian continents, with only a single valid Gondwanan taxon. Spicomellus afer gen. et sp. nov. appears to represent the earliest-known ankylosaur and the first to be named from Africa, from the Middle Jurassic (Bathonian–Callovian) of Morocco, filling an important gap in dinosaur evolution. The specimen consists of a rib with spiked dermal armour fused to its dorsal surface, an unprecedented morphology among extinct and extant vertebrates. The specimen reveals an unrealized morphological diversity of armoured dinosaurs during their early evolution, and implies the presence of an important but undiscovered Gondwanan fossil record

    Barremian intracontinental rift and Aptian Atlantic transgression in the northern boundary of the Central High Atlas (Morocco)

    No full text
    International audienceThe northern boundary of the Central High Atlas was affected by a transgression during the Aptian that reached the junction zone between the Middle and the High Atlas. In this sector (Naour-Aghbala) which corresponds to the presumed closure zone of this Aptian Atlantic marine trough, the sedimentary record reveals a strong dependence on the regional structural framework. The Barremian continental sedimentation is concentrated in an elongated W-E highly subsiding zone, limited to the south by the polyphase Aghbala-Afourer Fault Zone (AAFZ), which corresponds to the contact between the main Atlasic Belt and its northern boundary (Beni Mellal Atlas). The Aptian deposits preserve similar littoral marine characters from West to East without showing any confined facies, which could evoke the eastern limit of the gulf. On the other hand, towards the North, the Aptian layers rapidly change from marine to lagoonal then to continental facies. The paleogeographic boundary of the Aptian shoreline, oriented E-W, is locally controlled by the North El Ksiba Fault (NKF) in the North. The Aptian Atlantic transgression, closely linked to the narrow Barremian graben, shows a wide northward extension of the marine sedimentary area. The Barremian graben highlighted in the Aghbala-Naour area represents only a segment of a major east-west intracontinental rift that continued eastward with the more recent frontal thrust of the eastern Moroccan High Atlas. This faulted structure was the penetration axis of a double transgression: from the Tethys to the East and from the Atlantic Ocean to the West on the emerged Atlasic domain

    Electronic supplementary material from New Middle to? Late Jurassic dinosaur tracksites in the Central High Atlas Mountains, Morocco

    No full text
    Besides bones, fossil tracks and trackways are important sources of knowledge about dinosaur palaeobiology. Here, we report three new tracksites from two different synclines in the Imilchil area, Central High Atlas, Morocco. The tracks and trackways are preserved in fluvial deposits in different levels of the Isli Formation (Early Bathonian-? Upper Jurassic), and contain impressions made by sauropods, theropods and ornithopods, as well as tracks that might represent bird-like non-avian theropod dinosaurs. In addition to traditional field measurements, three-dimensional digital models of the track sites were created using photogrammetry. These new tracksites add to the rich faunal ichnoassemblage already recorded from the High Atlas Mountains and North Africa, which is considerably richer than the contemporaneous body fossil record, and also provide new data on dinosaurs-substrate interactions

    North Africa's first stegosaur: Implications for Gondwanan thyreophoran dinosaur diversity

    No full text
    Eurypoda, the major radiation of armoured dinosaurs, comprises the ankylosaurs and their sister group, the stegosaurs. As the earliest-branching major clade of ornithischian dinosaurs, the evolutionary history of Eurypoda is significant for understanding both the palaeobiology of bird-hipped dinosaurs and the composition of middle Mesozoic ecosystems. Eurypodans were diverse and abundant throughout the Late Jurassic and Cretaceous in Laurasia; in contrast, their remains are extremely rare in Gondwana. Herein, we describe a new genus and species of stegosaur from the Middle Jurassic of Morocco, Adratiklit boulahfa. Adratiklit is the first eurypodan from north Africa and the oldest definitive stegosaur from anywhere in the world. The genus is more closely related to the European stegosaurs Dacentrurus and Miragaia than it is to the southern African taxa Kentrosaurus and Paranthodon. Statistically significant correlations between the number of dinosaur-bearing formations, dinosaur-bearing collections, and eurypodan occurrences in Gondwana indicates that their fossil record is biased by both geological and anthropogenic factors. Tantalizing but fragmentary remains and trackways suggest that eurypodan diversity in Gondwana may have been as rich as that of Laurasia, and the prospects for future discoveries of new genera across Gondwana are therefore very good.‘The attached document is the authors’ final accepted/submitted version of the journal article. You are advised to consult the publisher’s version if you wish to cite from it
    corecore