41 research outputs found

    A Jurassic (Bathonian-Callovian) Daghanirhynchia brachiopod fauna from Jordan

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    A Jurassic (Bathonian-Callovian) brachiopod fauna from Jordan consists of seven rhynchonellid species all belonging to the genus Daghanirhynchia of which two are new: Daghanirhynchia rawyaensis and D. jordanica. Emended diagnoses are given for Daghanirhynchia daghaniensis and D. macfadyeni. Additional taxa described include Daghanirhynchia angulocostata, D. susanae and D. triangulata. Threedimensional reconstructions illustrate the internal morphology of the articulated shells for the first time in this genus. The material studied herein was collected from Wadi Zarqa in northwestern Jordan, almost due north of the Dead Sea, and to the east of the Rift Valley. Most species seem to be geographically restricted within the Jurassic Ethiopian Province, however specimens from Somalia and Ethiopia are larger in size than in other parts of the Province and shell size increases in stratigraphically younger specimens. The occurrence of Daghanirhynchia in India is the only appearance of the genus outside the Ethiopian Province

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    A new genus of terebratulid brachiopod from the Siegenian of the Rheinisches Schiefergebirge

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    A new genus Crassirensselaeria (Terebratulida, Rhenorensselaeriidae) from the Siegenian (middle Lower Devonian) of the Rheinisches Schiefergebirge (= Rhenish Slate Mountains, Germany) with the type−species Crassirensselaeria crassicosta is erected. Exceptionally well−preserved material of this taxon has recently been obtained from a temporary outcrop at an ICE (= InterCityExpress) railway construction site close to Aegidienberg near Bonn. As representatives of Crassirensselaeria have hitherto been included into the terebratulid genus Rhenorensselaeria; they are compared with the two Lower Devonian species of that genus from the Rheinisches Schiefergebirge: Rhenorensselaeria strigiceps and Rh. demerathia. Crassirensselaeria is chiefly distinguished from these by more globular shells, the presence of very strong plications, long and strong dental plates, different ventral muscle field, and thickened cardinalia. Representatives of the new genus are excellent index fossils for the Siegenian of the Rheinisches Schiefergebirge, even in deposits of restricted−marine and probably brackish environments. New material of articulated specimens in life position shows that both rhenorensselaeriid genera lived in clusters with the longitudinal axes of the shells oriented steep or perpendicular to the seafloor. The new genus is abundant in the Rheinisches Schiefergebirge (Germany) and the northern Ardennes (Belgium), it also occurs in the Hrubý Jeseník Mountains (Czech Republic). Its occurrence in Cornwall (Great Britain), however, is still questionable

    ASTRAELENIA SAOMAMEDENSIS N. SP. - A NEW GIGANTIC RHYNCHONELLID SPECIES AND ITS PALAEOBIOGEOGRAPHICAL IMPLICATIONS FOR THE PORTALEGRE SYNCLINE (CENTRAL PORTUGAL)

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    A new species of Astraelenia is described from ?Siegenian to Emsian strata of the Portalegre Syncline (Central Portugal). Astraelenia saomamedensis n. sp. differs in a smaller number of costae, a rather inconspicuous fold and sulcus, and larger and elongate shells from other species of Astraelenia. Astraelenia occurs today in northern Africa, Central and Western Europe; the new species shows Gondwanan origin according to faunal elements found in the stratigraphic vicinity. The migration of Astraelenia is described considering Lower Devonian regional transgression and regression events. The new species is found in monospecific clusters and an attempt for understanding its palaeoecology is presented.

    A new species of Ivdelinia Andronov, 1961 from the Moroccan givetian and its palaeoecological and palaeobiogeographical implications

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    The collection and study of benthic fauna from Middle Devonian carbonate buildups of the Maïder Basin in the eastern Anti-Atlas of Morocco permitted the taxonomic revision of previously described brachiopods from this area. Rhynchonellids dominate the brachiopod fauna. In this work, however, the focus is put on the description of a new gypidulid species, Ivdelinia pulchra, which belongs to the family Gypidulidae (subfamily Ivdelininae), found among the brachiopods from the Aferdou el Mrakib reef mound. It represents the youngest Ivdelinia species so far described and is compared with other ivdelinids. Ivdelinia pulchra occurs as densely packed communities which lived in a carbonate predominant environment during the earlier stage of reef mound growth, suggesting a more or less allochthonous state of these communities. However, this taxon does not properly belong to the reef guild. In addition we discuss the palaeoec-ology of the new species
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