Record details

    The latest Ordovician Hirnantia Fauna (Brachiopoda) in time and space
Statement of responsibility
    Jia-Yu Rong, Xu Chen, David A.T. Harper
    Chen, Xu
    Harper, David A. T.
    Rong, Jia-Yu
Source title - serial
    Vol. 95, no. 3
    p. 231-249
    12 obr., 4 s. bibl.
    Zkr. název ser.: Lethaia
Subject group
    pražská pánev
    stratigrafická hranice
    zóny biostratigrafické
Geographical name
    Argentina-San Juan
    Čína jihozápadní
    Velká Británie
Abstract (in english)
   The diachronous temporal and spatial distribution of the Hirnantia brachiopod fauna and the complicated pattern of terminal Ordovician events are documented through biostratigraphical analysis of the Ordovician-Silurian boundary strata in S China, Sibumasu, Xizang and elsewhere. The duration of these events (longer than the half Myr derived fro isotopic excursions) indicates that they were not abrupt and instantaneous. The presence of some core taxa of the Hirnantia fauna in the upper P. pacificus Biozone (known from their earliest occurrence in China) signals the start of increased water ventilation due to the invasion of cool water across the Yangtze Basin. Low- and higher-diversity Hirnantia faunas related to onshore, shallow-water and to offshore, deeper-water environments, respectively, developed first in the basal and upper N. extraordinarius-N. ojsuensis Biozone. Disappearance of most of the fauna in the early N.
   persculptus Biozone suggests that the glacial maximum started to decline. The presence of the Hirnantia fauna in the upper N. persculptus to the loer P. acuminatus biozones indicates the continuation of cool water environments in some places. The diachronous disappearance of deteriorating environments (earlier in later Hirnantian and finally in the early Rhuddanian) is associated with geographical heterogeneity. Occurrences of atrypids, pentamerids and spiriferids along with key elements of the Hirnantia fauna in N Guizhou provide a link between the Late Ordovician radiation and Early Silurian recovery of these major brachiopod groups
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    2. 10. 2007
Import date
    8. 8. 2012