TY - JOUR
T1 - Diatom species of the genus Rhizosolenia from Southern Ocean sediments
T2 - Distribution and taxonomic notes
AU - Armand, L. K.
AU - Zielinski, U.
PY - 2001
Y1 - 2001
N2 - The classification of diatom taxa in the genus Rhizosolenia Brightwell in Southern Ocean waters and sediments remains unclear. Our review demonstrates that considerable intertaxa confusion has occurred and continues to occur as a result of misapplied taxonomy. In general, valves of Rhizosolenia taxa within total diatom sediment assemblages are a minor, though common component, with only a few taxa sufficiently abundant for statistical analysis. We have endeavoured to clarify through literature and data set assessment the currently accepted taxon concepts in terms of otaria morphology, this being one of the most useful features available for the discrimination of fossil rhizosolenioids in Southern Ocean sediments. Otaria morphology allows separation of incomplete valves of preserved Rhizosolenia specimens to be determined from descriptions related to the complete cell. The identification of R. styliformis Brightwell, R. antennata f. semispina Sundström, and R. polydactyla Castracane f. polydactyla are addressed here in detail. The presence of Rhizosolenia species A, a taxon with similarities to the otaria-lacking, original descriptions of R. hebetata f. semispina (Hensen) Gran, is described and illustrated. Taxonomic notes, light microscopic representation and distributional data for several other Antarctic Rhizosolenia taxa are provided. The documentation of down-core occurrences of fossil rhizosolenioids in published material is poor. Our core material indicates relative abundance increases for Rhizosolenia species A and R. antennata f. semispina in glacial time sequences, which may constitute a valuable biostratigraphic tool for palaeoenvironmental reconstructions. Comments on winter resting stages are provided.
AB - The classification of diatom taxa in the genus Rhizosolenia Brightwell in Southern Ocean waters and sediments remains unclear. Our review demonstrates that considerable intertaxa confusion has occurred and continues to occur as a result of misapplied taxonomy. In general, valves of Rhizosolenia taxa within total diatom sediment assemblages are a minor, though common component, with only a few taxa sufficiently abundant for statistical analysis. We have endeavoured to clarify through literature and data set assessment the currently accepted taxon concepts in terms of otaria morphology, this being one of the most useful features available for the discrimination of fossil rhizosolenioids in Southern Ocean sediments. Otaria morphology allows separation of incomplete valves of preserved Rhizosolenia specimens to be determined from descriptions related to the complete cell. The identification of R. styliformis Brightwell, R. antennata f. semispina Sundström, and R. polydactyla Castracane f. polydactyla are addressed here in detail. The presence of Rhizosolenia species A, a taxon with similarities to the otaria-lacking, original descriptions of R. hebetata f. semispina (Hensen) Gran, is described and illustrated. Taxonomic notes, light microscopic representation and distributional data for several other Antarctic Rhizosolenia taxa are provided. The documentation of down-core occurrences of fossil rhizosolenioids in published material is poor. Our core material indicates relative abundance increases for Rhizosolenia species A and R. antennata f. semispina in glacial time sequences, which may constitute a valuable biostratigraphic tool for palaeoenvironmental reconstructions. Comments on winter resting stages are provided.
UR - http://www.scopus.com/inward/record.url?scp=0034764426&partnerID=8YFLogxK
U2 - 10.1080/0269249X.2001.9705520
DO - 10.1080/0269249X.2001.9705520
M3 - Article
AN - SCOPUS:0034764426
SN - 0269-249X
VL - 16
SP - 259
EP - 294
JO - Diatom Research
JF - Diatom Research
IS - 2
ER -