Record details

Title
    The Early Ludfordian leintwardinensis graptolite Event and the Gorstian-Ludfordian boundary in Bohemia (Silurian, Czech Republic)
Author
    Loydell, D. K.
    Manda, Š.
    Štorch, Petr
Language
    anglicky
Publication type
    článek v odborném periodiku
Source title - serial
    Palaeontology
Vol./nr.
    Roč. 57, č. 5
Pages
    s. 1003-1043
Year
    2014
Notes
    Projekt: GA205/09/0703, GA ČR3cav_un_auth*0252843
    Rozsah: 41 s. : P
Subject category
    biostratigraphy
    extinction
    Gorstian-Ludfordian boundary
    graptolites
    leintwardinensis Event;
    Silurian
Keyword
    Bohemia
    Boundary
    Czech
    Early
    Gorstian-Ludfordian
    Graptolite
    Leintwardinensis
    Ludfordian
    Republic
    Silurian
Abstract (in english)
   The late Gorstian through early Ludfordian hemipelagic succession of the Prague Synform preserves a rich fossil record dominated by planktic graptoloids associated with pelagic myodocopid ostracods, pelagic and nektobenthic orthocerid cephalopods, epibyssate bivalves, nektonic phyllocarids, rare dendroid graptolites, brachiopods, crinoids, trilobites, sponges and macroalgae. Faunal dynamics have been studied with particular reference to graptolites. The early Ludfordian leintwardinensis graptolite extinction Event manifests itself as a stepwise turnover of a moderate diversity graptolite fauna rather than an abrupt destruction of a flourishing biota. The simultaneous extinction of the spinose saetograptids at the top of S. leintwardinensis Biozone was preceded by a short-term acme of S. clavulus. Cucullograptids vanished from the fossil record in the lower part of the B. tenuis Zone. Limited indigenous speciation gave rise to Pseudomonoclimacis kosoviensis and Ps. cf. dalejensis.
   Egregiograptus - the only novel element, of cryptic origin - made its earliest occurrence in association with the latest cucullograptids. A post-extinction graptolite fauna of moderate diversity, composed for the most part of long ranging taxa, persisted through the tenuis Zone until new rediversification in the N. inexpectatus Zone. Unlike the graptoloids, shelly fauna did not suffer significant extinction in the early Ludfordian. The Gorstian/Ludfordian boundary is placed at the lowest occurrence of Saetograptus leintwardinensis in the Ludfordian GSSP. Elsewhere, the Gorstian/Ludfordian boundary has been placed at the base of the S. linearis Zone which has been considered roughly correlative with the leintwardinensis Zone. Indeed, our morphometric study places the world-wide index species Saetograptus linearis in synonymy with S. leintwardinensis and thus considerably enhances the biostratigraphical utility of the latter index species. Pseudomonoclimacis antiqua sp. nov.
    is described.
Contributor
    AV ČR Brno, Geologický ústav
Contributor code
    AV ČR, GLÚ
Source format
    U
Import date
    23. 10. 2014