Jean Galtier

In the Perdasdefogu Basin (Ogliastra, Sardinia) plants occurring in angular cherts are preserved as siliceous permineralizations. The plant assemblage consists of the genera Sphenophyllum, Arthropitys, Astromyelon, Palaeostachya, Pecopteris, Scolecopteris, Stewartiopteris, Psaronius, Ankyropteris, Anachoropteris; furthermore, probable medullosan wood and ovules, cordaitean stems, leaves and ovules, and Dadoxylon wood have been recorded. Arborescent marratialean ferns are the dominant elements with Pecopteris and Scolecopteris leaves being the most common; the calamiteans are the second in abundance. Generally the chert blocks contain a large number of plant fragments — roots and leaves are being almost equally represented — suggestive of a coal ball-like plant accumulation. More rarely a chert block may consist of a single plant part, for example a piece of wood. The preservation and accumulation of the plants are closely comparable to the silicified plant assemblages described from the Lower Per... RÉSUMÉ Flores silicifiées du Permien basal du Bassin de Perdasdefogu (SE de la Sardaigne) : comparaison et corrélation bio-chronostratigraphique avec les flores du Bassin d'Autun (Massif central, France). Dans le Bassin de Perdasdefogu (Ogliastra, Sardaigne) des cherts anguleux renferment des plantes préservées sous forme de perminéralisations siliceuses. L'assemblage comprend les genres Sphenophyllum, Arthropitys, Palaeostachya, Pecopteris, Scolecopteris, Stewartiopteris, Psaronius, Ankyropteris, Anachoropteris, du bois et des ovules appartenant probablement à des Médullosales, des tiges, feuilles et ovules de type cordaitales et, rarement, du bois de Dadoxylon. Les fougères arborescentes marratiales constituent l'élément dominant avec les feuillages Pecopteris et Scolecopteris comme fossiles les plus communs ; les sphénopsides calamitales sont deuxième en abondance. Généralement un spécimen de chert contient un grand nombre de fragments végétaux (racines et feuilles presque à égalité) suggestif d'une ac...

Galtier, J. and B. Meyer-Berthaud. (UMR Botanique et Bioinformatique, CIRAD, TA40/PS2, 34398 Montpellier, France). The diversification of early arborescent seed ferns. J. Torrey Bot. Soc. 133: 7–19. 2006.—Seed plants of the lowermost Carboniferous time (Tournaisian) display important differences in morphology and habit with at least two size classes. On one side are plants of modest stature with protostelic stems, manoxylic wood and large leaves, interpreted as calamopityan, buteoxylalean and lyginopteridalean seed ferns, and on the other side are arborescent plants, with trunks up to 2 metres in diameter, of which the systematic position remains unclear. We summarize present information on these trees characterized by a thick development of generally dense wood, a broad eustele consisting of a large number of discrete primary xylem strands, short internodes and deciduous medium-sized fronds. New data have been recently obtained on Pitus, the best known member of this group, on Eristophyton, Bili...

Raphogla rubra gen. n., sp. n., oldest representative of the (Tettigoniidea & Gryllidea) is described from the Upper Permian of the Lodève basin (France). Its phylogenetic relationships within the Ensifera are discussed. The new taxon occupies a very basal position, probably as sister group of the whole group (Tettigoniidea & Gryllidea).