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Rugose Corals (rugose + coral)
Selected AbstractsLife strategies of solitary undissepimented rugose corals from the upper member of the Picos de Europa Formation (Moscovian, Carboniferous, Cantabrian Mountains, NW Spain)LETHAIA, Issue 3 2001SERGIO RODRÍGUEZ Rugose corals belonging to the orders Metriophyllina, Stereolasmatina and Plerophyllina have been identified in the upper member of the Picos de Europa Formation (Moscovian). Corals occur in crinoidal limestones containing common bryozoans. The coral assemblage shows a high diversity. Mode of preservation and spatial distribution of corals demonstrate close relationships with biogenic components such as crinoids, bryozoans, brachiopods and bivalves. The morphology of corals provides valuable data for identifying their life strategies, four of which have been identified: liberosessile with straight growth, liberosessile with curved growth, fixosessile with straight growth and fixosessile with curved growth. Most corals from the Picos de Europa Formation appear to have been fixosessile with straight growth; they attached themselves to bioclasts and subsequently developed radiciform processes (mainly talons) to remain straight. [source] Structural,functional Aspects in the Evolution of Operculate Corals (Rugosa)PALAEONTOLOGY, Issue 4 2002Michael Gudo Among the Rugosa operculae were developed by only a few genera. One is the slipper,shaped Calceola and another is the pyramidal shaped Goniophyllum. On the basis of biological and morphological knowledge of recent corals, the two different bauplans of the soft bodies of Calceola and Goniophyllum have been reconstructed. The soft body (i.e. the polyp) of a rugose coral is thought to have all the basic structures of anthozoan polyps: a barrel,like body shape, a flat oral disc with tentacles, and a mouth from which a pharynx reaches inside the gastric cavity. Furthermore, as in all Anthozoa, Rugosa had internal mesenteries that act as tensile cords; during growth in the diameter further mesenteries were inserted. In contrast to all other Anthozoa, in the Rugosa new single mesenteries were added in four insertion sectors. The bauplans of Calceola and Goniophyllum differ in the pattern of mesentery insertion into these four sectors. Calceola had a serial insertion pattern and Goniophyllum had a symmetrical insertion pattern. They are representatives of the two different bauplans within the Rugosa. The lid corals are examples of convergent evolved genera; Calceola as well as Goniophyllum originated by quite simple modifications of the ancestral type. The peculiar shapes, the operculae and especially the straight hinges between the calyx and the lid(s) result only from mechanical necessity. Under special conditions (such as high sedimentation rates) these modifications of the corallites represent suitable tactics for survival. [source] Stratigraphy of upper Viséan carbonate platform rocks in the Carlow area, southeast IrelandGEOLOGICAL JOURNAL, Issue 1 2005P. Cózar Abstract The stratigraphy of the upper Viséan (Asbian to Brigantian) carbonate succession in southeast Ireland is revised on the basis of seven quarry and two borehole sections. Six lithological units have been distinguished, two units (units 1 and 2) in the upper Asbian Ballyadams Formation, and four units (units 4 to 6) in the Brigantian Clogrenan Formation (both formations are dated precisely using foraminiferans, calcareous algae and rugose corals). The boundary between the Ballyadams and Clogrenan formations is redefined 19,m below the horizon proposed by the Geological Survey of Ireland, and thus, lithological characteristics of both formations are redescribed. The upper part of the Ballyadams Formation is characterized by well-developed large-scale cyclicity, with common subaerial exposure surfaces. Fine- to medium-grained thin-bedded limestones with thin shales occur in the lower part of cycles, passing up into medium-grained pale grey massive limestones in the upper part. The Clogrenan Formation is composed mainly of medium- to coarse-grained thick limestone beds with variable presence of shales; but no large-scale cyclicity. There is a decrease in the number of subaerial exposure surfaces towards the top of the formation and common chert nodules; macrofauna occurs mostly concentrated in bands. The six units recognized in the Carlow area are comparable with other units described for the same time interval (Asbian,Brigantian) from south and southwest Ireland, demonstrating the existence of a stable platform for most parts of southern Ireland, controlled principally by glacioeustatics. Copyright © 2004 John Wiley & Sons, Ltd. [source] Life strategies of solitary undissepimented rugose corals from the upper member of the Picos de Europa Formation (Moscovian, Carboniferous, Cantabrian Mountains, NW Spain)LETHAIA, Issue 3 2001SERGIO RODRÍGUEZ Rugose corals belonging to the orders Metriophyllina, Stereolasmatina and Plerophyllina have been identified in the upper member of the Picos de Europa Formation (Moscovian). Corals occur in crinoidal limestones containing common bryozoans. The coral assemblage shows a high diversity. Mode of preservation and spatial distribution of corals demonstrate close relationships with biogenic components such as crinoids, bryozoans, brachiopods and bivalves. The morphology of corals provides valuable data for identifying their life strategies, four of which have been identified: liberosessile with straight growth, liberosessile with curved growth, fixosessile with straight growth and fixosessile with curved growth. Most corals from the Picos de Europa Formation appear to have been fixosessile with straight growth; they attached themselves to bioclasts and subsequently developed radiciform processes (mainly talons) to remain straight. [source] | ||||||||||