Isolated graptolites from the Lituigraptus convolutus Biozone (Silurian, Llandovery) of Dalarna, Sweden

David Loydell, J. Maletz

    Research output: Contribution to journalArticlepeer-review


    Isolated material of 13 graptolite species from the Aeronian (middle Llandovery) Lituigraptus convolutus Biozone is described. A considerable amount of late astogenetic peridermal thickening is revealed in Normalograptus scalaris and Rivagraptus bellulus. As a result, in the former, thecal morphology is modified from climacograptid to pseudoglyptograptid; in both species, the virgella becomes robust. In Metaclimacograptus minimus and Me. sp., it is shown that the dorsal metathecal wall forms the genicular hood, whereas in N. nikolayevi, the infragenicular wall of the succeeding theca forms the distal thecal apertural margin. Pribylograptus argutus exhibits typical pribylograptid thecae along the length of the available rhabdosome fragments. Characters differentiating Campograptus lobiferus from C. harpago include the greater dorso-ventral width and more rapid increase in dorso-ventral width of the former and the greater recurving of distal thecae and presence of thecal spines/processes on all thecae of the latter. Lituigraptus convolutus has rastritiform thecae proximally; thecal apertures throughout the rhabdosome are crescentic and laterally expanded.
    Original languageEnglish
    Pages (from-to)273-296
    Number of pages24
    Issue number2
    Publication statusPublished - Mar 2009


    Dive into the research topics of 'Isolated graptolites from the Lituigraptus convolutus Biozone (Silurian, Llandovery) of Dalarna, Sweden'. Together they form a unique fingerprint.

    Cite this