1,721,020 research outputs found
Corrélation des formations continentales permo-triasiques de part et d’autre du Sphénochasme ligure : bassins de Toulon-Cuers (Provence) et de la Nurra (Sardaigne). Conséquences paléogéographiques
No full textRonchi Ausonio, Durand Marc. Corrélation des formations continentales permo-triasiques de part et d’autre du Sphénochasme ligure : bassins de Toulon-Cuers (Provence) et de la Nurra (Sardaigne). Conséquences paléogéographiques. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 198-199
Terrestrial biota from the Lower Permian of the central Southern Alps (Orobic and Collio Basins) : a key for environmental considerations
No full textRonchi Ausonio, Santi Giuseppe. Terrestrial biota from the Lower Permian of the central Southern Alps (Orobic and Collio Basins) : a key for environmental considerations. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. pp. 200-201
Cordaites Unger 1850
No full textCordaites sp. (Fig. 9E) This radial section shows the excellent preservation of the lamina with vertical mesophyll plates separated by lacunae and palisade-like tissue in a leaf similar to the previous one.Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 62, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Cordaites lingulatus
No full textCordaites cf. lingulatus Grand’Eury, 1877 (Fig. 9F) This leaf, found associated with the stem of Figure 9A, has a thin lamina (0.4 mm), a smooth surface and very closely spaced veins (less than 0.4 mm interval, i.e. about 25 per cm). Rectangular sclerotic strands extend above and below veins; the mesophyll is differentiated into palisade and more or less spongy tissues. Despite similarities with the species C. lingulatus Grand’Eury as illustrated by Renault (1879) this leaf may represent variability of other species like Cordaites principalis Germar, as illustrated by Harms & Leisman (1961).Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 62, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Cordaites tenuistriatus
No full textCordaites tenuistriatus Grand’Eury, 1877 (Fig. 9C) In this leaf the lamina is thin and of variable thickness: 0.2 mm between veins to 0.4 mm at the level of veins due to the presence of triangular hypodermal sclerotic strands above and below the bundle sheath. This results in a typical superficial ribbing characteristic of the species C. tenuistriatus as illustrated by Renault (1879) from the Pennsylvanian of Grand-Croix. The interval between veins is less than 0.6 mm, i.e. about 17 veins per cm.Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 62, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Sphenophyllum
No full textSphenophyllum sp. (Fig. 5G) We only found two specimens of these small stems, partly decorticated but showing well-developed secondary xylem. There is no diagnostic feature allowing a specific identification. This genus extends up to the Early Permian where it has been found preserved as compressions at Autun (Igornay). FERNS Ferns, particularly marratialean tree ferns, are the most common element of the flora.Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 56, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Pecopteris
No full textPecopteris sp. (Fig. 8A) A transverse section of a vegetative pinnule, similar to those shown on Figure 7E, shows the fleshy texture of the lamina (300-400 µm thick) with palisade and spongy parenchyma; the pinnule margins are flexed downwards and prominent hairs are borne on the lower epidermis. Such pinnules are smaller but very similar in organization to the vegetative pinnules attributed to Scolecopteris oliveri from Autun by Scott & Holden (1933); they may belong to the same plant as the associated fertile pinnules described hereafter.Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 57, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Parataxospermum Z.M.Li 1993
No full textcf. Parataxospermum (Fig. 9I) Dispersed cardiocarpalean ovules of this type are the most common, occurring in about 1/10 of specimens. They are up to 1 mm long and 6 × 5 mm wide. They are characterized by a prominent sclerotesta up to 1 mm thick composed of large thick-walled cells 50 to 200 µm in diameter gradually decreasing in size in the outermost sclerotesta and near the base of the ovule. Detailed description of these ovules will be presented in another paper but it is worth mentioning that they are most similar with ovules from Carboniferous-Permian coal balls from Shanxi Province in China described by Li (1993).Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on pages 62-63, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Cordaites crassus Renault 1879
No full textCordaites cf. crassus Renault, 1879 (Fig. 9B [CC]; 9D) In contrast, this leaf found associated with the previous one, shows a very thick (up to 1 mm) lamina and a superficial surface smooth. Sclerotic strands do not extend to the bundle sheath and intermediate strands occur between veins as illustrated by Renault (1879) for specimens from Grand-Croix and by Harms & Leisman (1961) from American Pennsylvanian coal balls. The interval between veins is about 0.7 mm, i.e. about 14 veins per cm.Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 62, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
Cycadinocarpus augustodunensis Renault 1896
No full textCycadinocarpus augustodunensis (Brongniart) Renault, 1896 (Fig. 9H) Groups of dispersed ovules of this type are found in a few specimens. They are up to 9 mm long, 6-8 mm wide in the major plane and 3-5 mm wide in the minor plane of symmetry. They conform to the description of the species Cycadinocarpus augustodunensis (Brongniart) Renault (1896) from Autun. This ovule was previously described as Cordaicarpus augustodunensis by Brongniart (1881). The generic change, from Cordaicarpus to Cycadinocarpus, proposed by Renault (1896) was supported by Bertrand (1908). This ovule is mostly characterized by the irregular sclerotesta varying greatly in thickness and appearing trabeculate in tangential sections (Brongniart 1881: pl. III, fig. 14). Original type material of this species, kept in the Muséum national d’Histoire naturelle, Paris (MNHN), has been re-investigated by one of the authors (JG) and the non-artefactual nature of this irregular slerotesta was confirmed as well as the specific identification of the Sardinian ovules to the species of Autun.Published as part of Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), pp. 43-69 in Geodiversitas 33 (1) on page 62, DOI: 10.5252/g2011n1a4, http://zenodo.org/record/459694
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