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| 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 |
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| 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 |
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