|
|
|
|
|
| Nemyrovska, T.I.; Wagner, R.H.; Winkler Prins, C.F.; Montañez, I.. |
| Two different tectono-stratigraphic domains are recognised in the Cantabrian Mountains, Asturian-Leonese (Cantabrian Zone) and Palentian (Palentian Zone). The area under investigation belongs to the southern part of the Palentian Domain and attention is focused on the Upper Viséan to lowermost Bashkirian limestones at the village of La Lastra in northern Palencia. A new geological map of the Palentian Zone is accompanied by a more detailed map centred on La Lastra. The Barcaliente Limestone Formation (Serpukhovian to lowermost Bashkirian) occurs in the overturned limb of a recumbent anticline which constitutes the head of a south-verging major thrust unit, the Carrionas Thrust Sheet (Palentian Zone). It shows here a shallowing trend in the Serpukhovian.... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Serpukhovian; Bashkirian; Biostratigraphy; Palaeoecology; 42.65; 38.16. |
| Ano: 2011 |
URL: http://www.repository.naturalis.nl/record/428483 |
| |
|
|
| Wagner, R.H.; Hill, C.R.; El-Khayal, A. A.. |
| Pecopterid fronds bearing typically bilocular synangia, Gemellitheca saudica gen. et sp. nov., are described from the Unayzah plant bed in Saudi Arabia and the Gomaniimbrik Formation of the Hazro inlier in southeastern Turkey. The synangia are attached near the sharply incurved pinnule margin and extend across the whole or almost the whole half-width of the pinnules. Their apices lie near and in some cases over the midrib, and are curved abaxially away from it. The closest comparison is with Dizeugotheca Archangelsky & de la Sota, a Permian pecopterid with transversely placed fructifications which look very similar, but Dizeugotheca is described as having sori with sporangia consistently in groups of four, two of each group being largely overlapped by... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.21. |
| Ano: 1985 |
URL: http://www.repository.naturalis.nl/record/317484 |
| |
|
|
| Wagner, R.H.; Álvarez-Vázquez, C.. |
| An analysis of Alethopteris virginiana Fontaine & White from the lower Dunkard in the Appalachians of North America shows that three different taxa are likely to be represented in the initial illustration. The specific epithet ‘virginiana’ ought to be restricted to a form comparable to Callipteridium costei (Zeiller) Wagner, whereas the two other taxa are referred to pecopterid ferns. A neotype is proposed for Callipteridium virginianum (Fontaine & White) comb. nov. on the basis of topotypes. Zeiller’s illustration of ‘Alethopteris’ costei is reproduced for comparison. On the other hand, a full description and illustration are provided for Alethopteris leonensis Wagner, a species which had been identified previously with Alethopteris virginiana,... |
| Tipo: Article / Letter to the editor |
Palavras-chave: Alethopteris; Callipteridium; Pteridosperm; Stephanian; Carboniferous; 38.22. |
| Ano: 2010 |
URL: http://www.repository.naturalis.nl/record/361974 |
| |
|
|
| Hill, C.R.; Wagner, R.H.; El-Khayal, A. A.. |
| The marattialean fern Qasimia schyfsmae (Lemoigne) gen. et comb. nov. is described from the Late Permian plant bed at Unayzah in central Saudi Arabia. Although no organic matter is preserved, impregnation of the compressions by iron minerals at an early stage of diagenesis has partly mineralised the synangia and spores. The impressions in a fine-grained shale preserve epidermal cell outlines, including those of the stomata. Qasimia resembles Marattia closely in its bivalved synangia and in its monolaesurate spores with a warty or spiny ornament. It differs in the rounded rather than pointed apices of the pinnules and the greater density of veins, particularly in the vegetative pinnules. Unlike Marattia, its synangia characteristically extend across the... |
| Tipo: Article / Letter to the editor |
Palavras-chave: 38.21. |
| Ano: 1985 |
URL: http://www.repository.naturalis.nl/record/317391 |
| |
|
|
|
