A newly discovered, diverse sponge fauna of early Silurian age, is described from Gotland, Sweden. This is the first Silurian sponge assemblage known from Baltica, and the only diverse Llandoverian assemblage known worldwide. The fauna includes 20 genera and 29 species, of which three genera and six species are new. Eighteen species are new to Baltica. The fauna shows strong similarities to later Silurian assemblages in Arctic Canada, but one endemic species comprises ca. 50% of the fauna. The fauna shows that lithistid sponges recovered well from the late Ordovician extinction in some areas,…mehr
A newly discovered, diverse sponge fauna of early Silurian age, is described from Gotland, Sweden. This is the first Silurian sponge assemblage known from Baltica, and the only diverse Llandoverian assemblage known worldwide. The fauna includes 20 genera and 29 species, of which three genera and six species are new. Eighteen species are new to Baltica. The fauna shows strong similarities to later Silurian assemblages in Arctic Canada, but one endemic species comprises ca. 50% of the fauna. The fauna shows that lithistid sponges recovered well from the late Ordovician extinction in some areas, and became widely spread in the early Silurian. In contrast, non-lithistid sponges like, such as hexactinellids, appear to have evolved rapidly during the Late Ordovician - early Silurian interval, and some modern groups probably originated in inshore habitats.Hinweis: Dieser Artikel kann nur an eine deutsche Lieferadresse ausgeliefert werden.
Freek Rhebergen and Joseph Botting are the authors of A New Silurian (Llandovery, Telychian) Sponge Assemblage from Gotland, Sweden, published by Wiley.
Inhaltsangabe
Introduction 1 Institutional abbreviations 3 Geological setting 3 Material, methods, terminology 6 Systematic palaeontology 8 Phylum Porifera Grant, 1836 8 Class Demospongea Sollas, 1875 8 Order Orchocladina Rauff , 1895 8 Family Anthaspidellida Miller, 1889 8 Genus Archaeoscyphia Hinde, 1889 8 Archaeoscyphia minganensis Billings, 1859 8 Archaeoscyphia annulata Rigby, 1973 12 Archaeoscyphia gislei de Freitas, 1989 14 Archaeoscyphia rectilinearis de Freitas, 1989 16 Archaeoscyphia aulocopiformis de Freitas, 1989 18 Archaeoscyphia scalaria de Freitas, 1989 19 Archaeoscyphia attenuata de Freitas, 1989 21 Genus Finksella Rigby & Dixon, 1979 22 Finksella turbinata Rigby & Dixon, 1979 22 Genus Calycocoelia Bassler, 1927 24 Calycocoelia typicalis Bassler, 1927 24 Genus Climacospongia Hinde, 1884 25 Climacospongia undulata de Freitas, 1991 26 Genus Multistella Finks, 1960 28 Multistella leipnitzae nsp 29 Genus Somersetella Rigby & Dixon, 1979 32 Somersetella amplia Rigby & Chatterton, 1989 32 Somersetella digitata Rigby & Dixon, 1979 34 Family Streptosolenidae Johns, 1994 35 Genus Postperissocoelia ngen 35 Postperissocoelia gnisvardensis nsp 36 Family Chiastoclonellidae Rauff , 1895 38 Genus Chiastoclonella Rauff , 1895 39 Chiastoclonella spRauff , 1895 39 Subclass Tetractinomorpha Lévi, 1953 39 Order Streptosclerophorida Dendy, 1924 39 Suborder Eutaxicladina Rauff , 1894 39 Family Hindiidae Rauff , 1893 39 Genus Hindia Duncan, 1879 40 Hindia sphaeroidalis Duncan, 1879 40 Suborder Sphaerocladina Schrammen, 1910 42 Family Astylospongiidae Zittel, 1877 42 Genus Caryoconus Rhebergen & van Kempen, 2002 42 Caryoconus gothlandicus (Schlüter, 1884) 42 Genus Lindstroemispongia ngen 45 Lindstroemispongia cylindrata nsp 47 Order Spirosclerophorida Reid, 1963 48 Suborder Rhizomorina Zittel, 1878a 48 Family Haplistiidae de Laubenfels, 1955 48 Genus Haplistion Young & Young, 1877 48 Haplistion minutum Rigby & Dixon, 1979 50 Haplistion cylindricum Rigby & Dixon, 1979 52 Haplistion toftanum nsp 54 Haplistion spYoung & Young, 1877 57 Genus Warrigalia Rigby & Webby, 1988 59 Warrigalia robusta Rigby & Webby, 1988 59 Rhizomorina indet 62 Subclass Tetractininellida? Marshall, 1876 62 Order Hadromerida? Topsent, 1898 63 Family uncertain 63 Genus Opetionella von Zittel, 1878 63 Opetionella incompta nsp 63 Class Hexactinellida Schmidt, 1870 65 Order Lyssacinosida? von Zittel, 1877 65 Family uncertain 65 Genus Urphaenomenospongia ngen 65 Urphaenomenospongia euplectelloides nsp 66 Lyssacinosida? indet 69 Order and family uncertain 71 Hexactinellid indetA 71 Hexactinellid indetB 71 Spiculite 72 Class Stromatoporoidea Stearn, Webby, Nestor & Stock, 1999 74 Order Labechiida Kühn, 1927 74 Family Stylostromatidae Webby, 1993 74 Genus Pachystylostroma Nestor, 1964 74 Pachystylostroma sp 74 Order Clathrodictyida Bogoyavlenskaya, 1969 76 Family Clathrodictyidae Kühn, 1939 76 Genus Clathrodictyon Nicholson & Murie, 1878 76 Clathrodictyon sp 76 Order Stromatoporida Stearn, 1980 76 Family Syringostromellidae Stearn, 1980 76 Genus Syringostromella Nestor, 1966 76 Syringostromella sp 76 Order Amphiporida Rukhin, 1938 76 Family Amphiporidae Rukhin, 1938 76 Genus Amphipora Schulz, 1883 76 Amphipora sp 76 Palaeobiogeography and community evolution 77 Taphonomy 80 Palaeoecology and palaeoenvironmental interpretation 80 Conclusions 83 Acknowledgements 83 References 83
