Early Paleocene-Late Eocene diatoms from the Blake Nose Western North Atlantic Ocean
Jakub Witkowski
<p> The Blake Nose area (western North Atlantic; approximately 350 km east of Florida, USA) represents the longest currently available single-locality record of diatom evolution, spanning approximately 30 million years of the early Cenozoic Era. </p> <p> This study provides a detailed taxonomic account of the diatom assemblages found in the lower Paleocene through upper Eocene deep-sea sediments recovered by Ocean Drilling Program Leg 171B from the Blake Nose. The main study sites are Holes 1050A, 1050C and 1051A. For comparative purposes, materials from other deep-sea holes and onshore sites are included as well. </p> <p> A total of 137 taxa representing 60 genera are examined using scanning electron and/or light microscopy. Two new combinations are performed (<i>Psammodiscus praenitidus</i> (Fenner) J. Witkowski, n. comb. and <i>Sheshukovia castellifera</i> (Grunow) J. Witkowski, n. comb.), and ten species are proposed as new (<i>Brightwellia plana</i> J. Witkowski, n. sp.; <i>Detonia wadeae</i> J. Witkowski, n. sp.; <i>Distephanosira gleichiae</i> J. Witkowski, n. sp.; <i>Euodiella beatae</i> J. Witkowski, n. sp.; <i>Hemiaulus curvatuloides</i> J. Witkowski, n. sp.; <i>Hemiaulus imperator</i> J. Witkowski, n. sp.; <i>Hemiaulus jordani</i> J. Witkowski, n. sp.; <i>Hemiaulus oreshkinae</i> J. Witkowski, n. sp.; <i>Medlinia? subtriangularis</i> J. Witkowski & P.A. Sims, n. sp.; and <i>Triceratium harwoodii</i> J. Witkowski, n. sp.). </p> <p> Emphasis in this study in on stratigraphic and geographic distribution of the diatom taxa encountered in the Blake Nose cores, and on documenting their morphological variability. </p> <p> The overall aim of this work is to provide a reference for future biostratigraphic and paleoceanographic studies involving early Paleogene marine diatoms. </p>
