Puncticulata versiformis sp. nov. and Cyclotella kathmanduensis sp. nov. (Bacillariophyta), new fossil species from Middle Pleistocene lacustrine sediments, Kathmandu, Nepal Himalaya

Tatsuya Hayashi, Yoshihiro Tanimura, Harutaka Sakai

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

New fossil species, Puncticulata versiformis sp. nov. and Cyclotella kathmanduensis sp. nov., are described from lacustrine sediments in the Kathmandu Basin on the southern slope of the Nepal Himalaya. They were dominant in the Middle Pleistocene. Both LM and SEM observations reveal their unique morphological features. Puncticulata versiformis is characterized by (1) various valve outlines (circular, elliptical, or oval), (2) a tangentially undulate central area, (3) a complex alveolar structure composed of three kinds of costae (thick costae, thin costae, and thin and short costae), (4) well-developed spines (Y-shaped and tapering) located on one side of the valve face/mantle area junction, and (5) a valvocopula with an extremely undulate margin. The species-specific feature of C. kathmanduensis is the presence of two kinds of alveolate zones in a single valve: type-1 zone composed only of normal costae, and type-2 zone composed of both normal costae and recessed costae bearing fultoportulae. Changes in valve ornamentation occur in these two species from initial valves to vegetative valves. In P. versiformis, the arrangement of areolae with internal domed cribra and fultoportulae in the central area changes from radial rows in the initial valve to groups in the vegetative valve. In the initial valve of C. kathmanduensis, the type-1 alveolate zone is generally absent.

Original languageEnglish
Pages (from-to)304-318
Number of pages15
JournalJournal of Phycology
Volume43
Issue number2
DOIs
Publication statusPublished - Apr 1 2007

All Science Journal Classification (ASJC) codes

  • Aquatic Science
  • Plant Science

Fingerprint Dive into the research topics of 'Puncticulata versiformis sp. nov. and Cyclotella kathmanduensis sp. nov. (Bacillariophyta), new fossil species from Middle Pleistocene lacustrine sediments, Kathmandu, Nepal Himalaya'. Together they form a unique fingerprint.

  • Cite this