Podrobnosti záznamu

    New Silurian murchisoniid gastropods from Alaska and a review of the genus Coelocaulus
    Blodgett, R.
    Frýda, Jiří
    Rohr, D.
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Short Notes on Alaska Geology
    Roč. 120, č. October
Výraz tezauru
    Gastropoda, evolution, Paleozoic
Klíčové slovo
Abstrakt (anglicky)
   Coelocaulus karlae n. sp. and Medfracaulus cooki n. gen., n. sp. are described from the Silurian of west-central and southeastern Alaska respectively. Coelocaulus is redefined to limit the content to selenizone-bearing murchisoniids with a deep, straight-walled umbilicus and without a columellar flange. The presence of a deep umbilicus in high-spired shells cannot be used alone as a diagnostic character of Coelocaulus, as on this basis many other non-murchisoniid species (mainly based on steinkerns) have erroneously been attributed to the genus. Establishment and recognition of these unusually large, deeply umbilicate murchisoniid shells is important for the Silurian biostratigraphy of Alaskan terranes. Both genera are abundant and are characteristic of Upper Silurian strata of west-central Alaska. Similar morphotypes are unknown from rocks located undoubtedly on the North American continent (Laurentia) during the Late Silurian.
    Česká geologická služba
Kód přispěvatele
    ČGS (RIV)
Zdrojový formát
Datum importu
    15. 10. 2014