Eocene–Oligocene paleoecology and the diatom genus Kisseleviella Sheshukova-Poretskaya from the Victoria Land Basin, Antarctica Matthew P. Olney a, * , Reed P. Scherer a , Steven M. Bohaty b , David M. Harwood c a Department of Geological and Environmental Geosciences, Northern Illinois University, DeKalb, IL 60115, USA b Earth Sciences Department, University of California, Santa Cruz, CA 95064, USA c Department of Geosciences, University of Nebraska-Lincoln, Lincoln, NE 68588-0340, USA Received 1 September 2005; received in revised form 21 September 2005; accepted 21 September 2005 Abstract The Cape Roberts Project (CRP) recovered a composite Eocene to lower Miocene stratigraphic sequence from the Victoria Land Basin, Antarctica, which includes four new species, described herein, of the biostratigraphically useful fossil marine diatom genus Kisseleviella . Specimens of this extinct genus occur predominantly in neritic sediments, which along with the chain-forming nature and morphological similarity to extant benthic genera (e.g. Cymatosira) suggest that Kisseleviella was tychopelagic. The species of Kisseleviella described here appear to be endemic to the Antarctic region with an ecological preference for nearshore environments. The polythermal, subpolar glacial regime invoked for the late Eocene–early Miocene may have acted as a significant driver of speciation events in Antarctic Kisseleviella . Phylogenetic analysis of fossil genera such as Kisseleviella allows the development of a neritic biostratigraphic zonation. New taxa formally proposed are: Kisseleviella tricoronata, Kisseleviella cicatricata , Kissele- viella gaster and Kisseleviella faballiforma . D 2005 Elsevier B.V. All rights reserved. Keywords: marine diatoms; Antarctica; Eocene; Oligocene; Miocene; taxonomy; endemism; paleoecology 1. Introduction Siliceous microfossils (including diatoms, silico- flagellates, ebridians) are particularly useful for both biostratigraphic and paleoenvironmental studies in Ce- nozoic Antarctic shelf sediments, where calcareous microfossils are rare. The presence/absence of siliceous microfossils may indicate ice conditions, for example seasonal sea ice cover or ice shelf/ice sheet expansion. Specific taxa may provide information on a wide range of environmental parameters, such as salinity, water depth, bottom substrate, water column stratification and nutrient conditions. Furthermore, fossil taxa with discrete geographical ranges and continuous stratigraph- ic records may be used to infer evolutionary processes. Taxonomic study of four new species of the extinct marine diatom genus Kisseleviella reveals new evi- dence that helps determine its systematic position. In stratigraphic and paleoenvironmental context, the anal- ysis provides impetus for the development of new hypotheses concerning Antarctic endemism and speci- ation in neritic and littoral environments. Paleoenviron- mental interpretation of the new taxa described herein agrees with previous sedimentological and multi-proxy 0377-8398/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.marmicro.2005.09.003 * Corresponding author. Tel.: +1 815 753 1943; fax: +1 815 753 1945. E-mail addresses: matt@geol.niu.edu (M.P. Olney), reed@niu.edu (R.P. Scherer), sbohaty@es.ucsc.edu (S.M. Bohaty), dharwood1@unl.edu (D.M. Harwood). Marine Micropaleontology 58 (2005) 56 – 72 www.elsevier.com/locate/marmicro