Evolutionary trends of Famennian icriodids in the Dinant and Vesdre basins (Conodonts, Belgian upper Devonian)
Dreesen, R.; Houlleberghs, E. (1980). Evolutionary trends of Famennian icriodids in the Dinant and Vesdre basins (Conodonts, Belgian upper Devonian). Ann. Soc. géol. Belg. (1968) 103: 111-141
In: Annales de la Société géologique de Belgique. Vaillant-Carmanne: Liège. ISSN 0037-9395, more
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| Keywords |
Geological time > Phanerozoic > Paleozoic > Palaeozoic > Devonian
Geological time > Phanerozoic > Paleozoic > Palaeozoic > Devonian > Devonian, Upper
Geological time > Phanerozoic > Paleozoic > Palaeozoic > Devonian > Devonian, Upper > Famennian
Conodonta
Belgium [Marine Regions]
Marine/Coastal |
| Authors | | Top |
- Dreesen, R.
- Houlleberghs, E.
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| Abstract |
Two different probably depth- and/or facies-related morphological groups are recognized within the "shallow water" genus Icriodus of the Belgian Famennian: the "Icriodus alternatus group" dominates in the relatively quiet offshore marine sediments of the Lower Famennian ("Groupe des Schistes de la Famenne "), where as the "Icriodus cornutus-costatus group" characterizes the more nearshore, turbulent facies of the Upper-Famennian ("Groupe des Psammites du Condroz"). A probable endemic morphological evolution is suggested for the latter group. A phylomorphogenetical lineage has been observed between I. alternatus BRANSON & MEHL and I. cornutus SANNEMANN at the base of the Famennian. The interspecific morphological relations and the intraspecific morphological variability within the different Icriodus-stock are discussed. Three new morphotypes of I. alternatus, one new subspecies of I. cornutus and two new subsepcies of I. costatus (THOMAS) are described; their stratigraphical range is discussed. |
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