An unusual freshwater diatom with bilobate ends from the Mid-Miocene of East Antarctica: Staurosirella tigris sp. nov. (Fragilariaceae, Bacillariophyta)

• Published in: Phytotaxa
• Main Authors: HARPER, MARGARET A., MORALES, EDUARDO A., VAN DE VIJVER, BART
• Format: Article in Journal/Newspaper
• Language: English
• Published: Magnolia press 2022
• Subjects: Antarctica; Friis Hills; Miocene flora; polar wetlands; Staurosirella; tundra ponds; Algae; East Antarctica; Antarc*; Tundra
• Online Access: https://www.mapress.com/pt/article/view/phytotaxa.541.2.10

A new species of araphid diatoms with bilobate ends is described as Staurosirella tigris sp. nov. It was found in mid-Miocene glacial-lacustrine sediments in the Friis Hills, Antarctica. The new diatom is placed in Staurosirella because it has striae composed of apically-oriented lineolae, separated by long, thin vimines, and it lacks rimoportulae. It can be easily distinguished by its rectangular valve shape with bilobate ends, differing from Staurosirella grunowii, another four-lobed Miocene species, by having a rectangular central portion to its valves instead of being cross-shaped with the four lobes arising from a common central area. Also, the distribution of the new species is different, to date only being found in Antarctica, while S. grunowii is restricted to the Northern Hemisphere.