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See detailBiostratigraphic significance of brachiopods near the Devonian–Carboniferous boundary
Mottequin, Bernard ULg; Brice, Denise; Legrand-Blain, Marie

in Geological Magazine (2014), 151

The biostratigraphic significance of selected uppermost Famennian (Upper Devonian) and lower Tournaisian (Mississippian) brachiopod genera, belonging to the orders Rhynchonellida (e.g. Araratella ... [more ▼]

The biostratigraphic significance of selected uppermost Famennian (Upper Devonian) and lower Tournaisian (Mississippian) brachiopod genera, belonging to the orders Rhynchonellida (e.g. Araratella), Spiriferida (e.g. Sphenospira, Prospira), Spiriferinida (Syringothyris) and Productida (except Chonetidina), is discussed. Owing to the difficulties of identifying productidine and strophalosiidine genera, in contrast to rhynchonellides and spiriferides, the biostratigraphic potential of the former has generally been overlooked. Brachiopods flourished in neritic environments that were unfavourable for conodonts and ammonoids. In the absence of the latter traditional marker fossils, they are potentially important for locating the Devonian–Carboniferous boundary in shallow water depositional settings in conjunction with rugose corals and foraminifers. On a worldwide scale, further work is required to reach a better assessment of the aftermath of the Hangenberg biological Crisis on brachiopods, notably in revising the faunas from the classical areas of the Famennian and Tournaisian stages in Western Europe. [less ▲]

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See detailA new Lower Cretaceous ichthyosaur from Russia reveals skull shape conservatism within Ophthalmosaurinae
Fischer, Valentin ULg; Arkhangelsky, Maxim; Uspensky, Gleb et al

in Geological Magazine (2014), 151(1), 60-70

Ophthalmosaurinae is a recently recognized clade of derived ichthyosaurs (marine reptiles) ranging from the Bajocian (Middle Jurassic) to the late Albian (late Early Cretaceous). Whereas the Middle-Late ... [more ▼]

Ophthalmosaurinae is a recently recognized clade of derived ichthyosaurs (marine reptiles) ranging from the Bajocian (Middle Jurassic) to the late Albian (late Early Cretaceous). Whereas the Middle-Late Jurassic ophthalmosaurine Ophthalmosaurus is often regarded as a hyperspecialized deep diver, very little is known about the anatomy, evolutionary history, and ecology of Cretaceous ophthalmosaurines because of the scarcity of the fossils and the lack of well-preserved skull material. Here, we describe the skull of a new basal ophthalmosaurine ichthyosaur, Leninia stellans gen. et sp. nov., from the lower Aptian of western Russia, and compare the ocular characteristics of ophthalmosaurids. Leninia is recovered as a basal ophthalmosaurine; it possesses unique traits such as star-shaped frontal–parietal sutures as well as features previously thought to be unique to Ophthalmosaurus such as a supratemporal–stapes contact. A large sclerotic aperture – significantly bigger than in platypterygiine ophthalmosaurids and similar to that of the largest-eyed modern animals (giant and colossal squids) – and reduced dentition appear widespread within ophthalmosaurines. This conservatism suggests ophthalmosaurine ophthalmosaurids occupied similar ecological niche(s) throughout their long evolutionary history. [less ▲]

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See detailMary Anning’s legacy to French vertebrate palaeontology
Vincent, Peggy; Taquet, Philippe; Fischer, Valentin ULg et al

in Geological Magazine (2014), 151(1), 7-20

The real nature of marine reptile fossils found in England in between the 1700s to the beginning of the 1900s remained enigmatic, until Mary Anning's incredible fossil discoveries and their subsequent ... [more ▼]

The real nature of marine reptile fossils found in England in between the 1700s to the beginning of the 1900s remained enigmatic, until Mary Anning's incredible fossil discoveries and their subsequent study by eminent English and French scientists. In 1820, Georges Cuvier acquired several ichthyosaur specimens found by Mary Anning, now kept or displayed in the Palaeontology Gallery of the MNHN in Paris. Four years later, Cuvier obtained a plesiosaur specimen from Mary Anning, only the second ever discovered. Cuvier was fascinated by these fossils and their study allowed him to apply his comparative anatomical method and to support his catastrophist theory. We re-examined these important specimens from an historical point of view and herein describe them taxonomically for the first time since Cuvier’s works. The Paris specimens belong to two different ichthyosaur genera (Ichthyosaurus and Leptonectes) and one plesiosaur genus (Plesiosaurus). [less ▲]

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See detailUpper Silurian miospores from the Precordillera Basin, Argentina: biostratigraphic, palaeonvironmental and palaeogeographic implications
Rubinstein, C.V.; Garcia Muro, V.J.; Steemans, Philippe ULg

in Geological Magazine (2013)

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See detailMarine vertebrate remains from the Toarcian-Aalenian succession of southern Beaujolais, Rhône, France
Vincent, Peggy; Martin, Jérémy; Fischer, Valentin ULg et al

in Geological Magazine (2013), 150(5), 822834

A previously undocumented marine vertebrate fauna comprising ichthyosaur, plesiosaur, marine crocodilian and fish remains from the Toarcian-Aalenian succession at Lafarge quarry, southern Beaujolais ... [more ▼]

A previously undocumented marine vertebrate fauna comprising ichthyosaur, plesiosaur, marine crocodilian and fish remains from the Toarcian-Aalenian succession at Lafarge quarry, southern Beaujolais, Rhône, France is described on the basis of both historical collections and new discoveries. The taxonomic composition of the Lafarge quarry marine vertebrate assemblage highlights its cosmopolitan nature and strong relationships with taxa known from elsewhere in Europe. Several groups are recorded for the first time in the Toarcian-Aalenian succession of France, implying new palaeobiogeographic interpretations, and prompting discussion of marine amniote diversity during this interval. [less ▲]

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See detailThe early land plants from the Armorican Massif: sedimentological and palynological considerations on age and environment
Strullu-Derrien, Christine; Ducassou, Céline; Ballèvre, Michel et al

in Geological Magazine (2010), 147(6), 830-843

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See detailMorphometric analysis of proposed evolutionary lineages of Early Devonian land plant spores
Breuer, P.; Stricanne, L.; Steemans, Philippe ULg

in Geological Magazine (2005), 142(3), 241-253

Early Devonian miospore assemblages from 'La Gileppe' (Eastern Belgium) include five varieties of trilete spore belonging to the genus Emphanisporites. These five varieties show a continuous variation of ... [more ▼]

Early Devonian miospore assemblages from 'La Gileppe' (Eastern Belgium) include five varieties of trilete spore belonging to the genus Emphanisporites. These five varieties show a continuous variation of their morphological characteristics. The variation in morphological characteristics can be related to the evolution of morphological features and allows us to define the Emphanisporites micromatus Morphon. A statistical evaluation of this population highlights the interdependence of almost all morphological parameters. This study proves the increase in size of ornamental and structural parameters over several million years. The biometric changes and the progressive replacement of older morphotypes by younger ones indicate that a temporal link exists between these different varieties. Two phylogenetic hypotheses for the E. micromatus Morphon are proposed. This morphological evolution is so far observed only on the Eastern Old Red Sandstone Continent and defines a palaeophytogeographic sinuosus-zavallatus Province. [less ▲]

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See detailThe plant Leclercqia (Lycopsida) in Gondwana: implications for reconstructing Middle Devonian palaeogeography
Meyer-Berthaud, B.; Fairon-Demaret, Muriel ULg; Steemans, Philippe ULg et al

in Geological Magazine (2003), 140(2), 119-130

Abundant and well-preserved material of the ligulate lycopsid genus Leclercqia is reported from a new Middle Devonian locality in northeastern Queensland (Australia). The plants occur in a chert horizon ... [more ▼]

Abundant and well-preserved material of the ligulate lycopsid genus Leclercqia is reported from a new Middle Devonian locality in northeastern Queensland (Australia). The plants occur in a chert horizon in the Storm Hill Sandstone of the Dosey-Craigie Platform. Lithological data and conodont analyses combined with information from in situ spores provide an age for the plant levels ranging from Eifelian, possibly Middle Eifelian, to Early Givetian. Plant taxonomic identification is based on vegetative and fertile stems that display both external morphology and anatomy. This material represents the best documented occurrence of Leclercqia outside Laurussia and possibly the earliest in Gondwana; it provides evidence that colonization of Gondwana by the species L. complexa was contemporaneous to that of Siberia and Kazakhstan. Analysis of the distribution patterns of L. complexa suggests that it was adapted to a wide range of environments, but within certain limits which we hypothesize to be those of a climatic belt. Such considerations support previous studies using other biological data, such as faunas and palynomorphs, for reconstructing Devonian palaeogeography. They favour a close proximity of Laurussia and Gondwana rather than the occurrence of a wide ocean separating the two palaeocontinents in Middle Devonian times. [less ▲]

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See detailVila Maria Formation (Silurian, Parana Basin, Brazil): integrated radiometric and palynological age determinations
Mizusaki, A. M. P.; Melo, J. H. G.; Vignol-Lelarge, M. L. et al

in Geological Magazine (2002), 139(4), 453-463

Fresh shale samples taken from a well-known outcrop section of the Silurian Vila Maria Formation, located on the northeastern margin of the Parana Basin (Tres Barras Farm, Goias State, central-western ... [more ▼]

Fresh shale samples taken from a well-known outcrop section of the Silurian Vila Maria Formation, located on the northeastern margin of the Parana Basin (Tres Barras Farm, Goias State, central-western Brazil), have been analysed for both palynological and radiometric age determinations. The rocks yielded a fairly diverse, age-definitive cryptospore assemblage, and the same samples proved suitable for Rb-Sr analysis, despite Silurian sedimentary rocks being rarely suited to radiometric dating techniques. This study thus introduces an alternative, independent method for estimating the minimum depositional age of the Vila Maria Formation. The Rb-Sr age value has been calculated via an isochron diagram that yields 435.9 +/- 7.8 Ma. Accordingly, the latter value is interpreted as the minimum depositional age of the analysed Vila Maria strata, implying their deposition during Llandovery times. This concurs with the palynological results, which indicate an age no older than Early Silurian and, more particularly, favour an Early to Middle Llandovery (Rhuddanian-Early Aeronian) attribution. [less ▲]

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See detailReview on "Perspective on Biogeochemistry" by E.T. Degens. Springer-Verlag
Dauby, Patrick ULg

in Geological Magazine (1989)

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