Fragilariopsis tigris sp. nov., a New Late Pliocene Antarctic Continental Shelf Diatom with Biostratigraphic Promise

Authors

Christina R. Riesselman, Eastern Geology and Paleoclimate Science Center, U.S. Geological SurveyFollow

Date of this Version

2012

Citation

Micropaleontology (2012) 58(4): 367-376.

Comments

U.S. Government work.

Abstract

Anew species within the genus Fragilariopsis, F. tigris, is described and illustrated using light microscopy and scanning electron microscopy. This species is restricted to a single 8-meter-thick diatom unit within the 585-meter-long section of alternating diatomites and diamictites recovered in the upper portion of the ANtarctic geological DRILLing (ANDRILL) McMurdo Ice Shelf Project (MIS) AND-1B marine sediment core. This new taxon from a diverse, well-preserved diatom assemblage is inferred to be the youngest member of the well-documented, biostratigraphically useful F. praeinterfrigidaria – F. interfrigidaria – F. weaveri lineage and may represent a near-shore corollary to the open-ocean species F. weaveri. Based on available chronostratigraphic data from AND-1B, F. tigris appears to be restricted to the earliest late Pliocene (first occurrence datum ~3.2 Ma) and is extinct before 3.0 Ma.