Late Devonian and early Carboniferous Rugosa from Western Pomerania, northern Poland

Abstract

The taxonomic description of the Late Devonian and Early Carboniferous Rugosa from the boundaty area of the Precambrian East European Craton and the Palaeozoic platform of Central Europe is presented. Palaeontological analysis and the stratigraphical distribution of the corals in Western Pomerania enabled recognition of several faunistic events, which reflect evolutionaty trends in rugose corals.The pre-crisis Frasnian coral fauna, dominated by colonial forms, both massive [Disphyllia laxa (GURICH, 1896), Hexagonaria hexagona kowalae WRZOLEK, 1992, ?Frechastraea] and branching [Disphyllum kweihsiense YOH, 1937, Peneckiella ?fascicularis (SOSHKINA, 1952), Thamnophyllum monozonatum (SOSHKINA, 1939), Peneckiella szulczewskii ROZKOWSKA, 1979], developed on the carbonate platform extending along the edge of the East European Craton. The similarity of these faunas to Rugosan faunas from southern Poland is significant.The coral fauna was reduced significantly after the Kellwasser crisis. Colonial corals disappeared altogether and solitary dissepimented forms were markedly reduced. The subsequent Late Famennian radiation caused a significant quantitative and qualitative differentiation of the coral faunas. In addition to the well-known 'Cyathaxonia fauna', warm and shallow-water solitary corals appeared in the latest Famennian. The stratigraphically important taxa of the latest Famennian include: Campophyllum MILNE-EDWARDS & HAIM, 1850, ?Palaeosmilia aquisgranense (FRECH, 1885), Bounophyllum pomeranicum sp. nov. and Guelichiphyllum kowalense ROZKOWSKA, 1969.The latest Famennian regression caused subdivision of the Pomeranian area into at least two sedimentary basins, separated by shallows, with peculiar ecological conditions, and the appearance of numerous endemic taxa. This regressive interval contains, however, numerous levels yielding less restricted faunas, which suggest the intermittent appearance of more open-sea conditions.