Phylogenetic analysis confirms the taxonomic placement of the marine flagellate Hermesinum adriaticum (Thecofilosea, Cercozoa, Rhizaria)

Abstract

Hermesinum adriaticum is a rare marine and brackish flagellate that is of considerable interest due to its markable and fossilizable siliceous skeleton. Based on this skeleton, Hermesinum was initially considered a microalga of the Dictyochophyceae (Ochrophyta, Stramenopiles). Later on, it was assigned to the Ebriida due to its similarity to Ebria tripartita. The taxonomic assignment of the Ebriida, however, changed several times until it was placed within the Thecofilosea (Cercozoa, Rhizaria), based on genetic data of E. tripartita. We sequenced the 18S marker gene sequence of Hermesinum and confirm the close relationship of Ebria and Hermesinum.

Keywords: Ebria tripartita; Ebriaceae; Ebriida; brackish water; microfossils; silica skeleton.