Open AccessEarly Llandovery monograptids from Bornholm and the southern Urals: taxonomy and evolution
Author(s) -
T. N. Koren,
Merete Bjerreskov
Publication year - 1998
Publication title -
bulletin of the geological society of denmark
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.674
H-Index - 28
eISSN - 2245-7070
pISSN - 0011-6297
DOI - 10.37570/bgsd-1998-44-01
Subject(s) - biozone , taxonomy (biology) , paleontology , geology , ecological succession , genus , biostratigraphy , biology , zoology , botany
The most complete Lower Llandovery succession of mudrocks yielding graptoliteswithin the ascensus, acuminatus and vesiculosus Biozones was studied in theBillegrav-1 core, South Bornholm. Special attention is given to the taxonomyand stratigraphical ranges of monograptids found in the vesiculosus Biozone inthe core and nearby exposures in Øle Å. Monograptids of the ascensus-acuminatusand vesiculosus Biozones were also discovered in condensed carbonaceous shalesequences of the Sakmara Formation in the southern Urals. Monograptids fromBornholm and the southern Urals are described, and referred to 5 genera and 17species (4 new and 4 in open nomenclature). The new genus Huttagraptus (typespecies H< praestrachani) is erected. Based on the present taxonomical studiesthe main morphological trends, phylogenetical relationships and diversity dynamics of the earliest monograptids are discussed.