Srinivasania Sundarbanensis gen. et sp. nov., a New Agglutinated Benthic Foraminifer from the World's Largest Mangrove Ecoregion, the Sundarbans, India

Abstract

We describe Srinivasania sundarbanensis n. gen. et sp. nov., a multichambered textulariid foraminifer from the world's largest mangrove ecosystem, the Sundarbans, India. The new genus has an agglutinated wall structure, planispirally coiled test, and a single high-arched equatorial aperture located at the base of the final chamber with a narrow, agglutinated lip and with morphological similarity to the genera GobbettiaDhillon, 1968, and HaplophragmoidesCushman, 1910. Phylogenetic analyses, using partial small subunit rRNA gene, partial large subunit rRNA gene, and concatenated (LSU+SSU) sequence data clearly show the placement of this new taxon among other textulariid foraminifers, distant from all other genera in a strongly supported clade. In the new genus and species, the test is discoidal, measuring 100 to 350 µm in diameter with six to seven chambers in the final whorl. Elemental characterization (SEM-EDS) of the agglutinated test wall reveals a preference for quartz grains (SiO2) to construct its test. It is a common species and is presently known only from the northern marsh environments of Indian Sundarbans.