Cymbella yangtzensis Li & Metzeltin, 2013

Gong, Zhijun, Li, Yanling, Metzeltin, Ditmar & Lange-Bertalot, Horst, 2013, New species of Cymbella and Placoneis (Bacillariophyta) from late Pleistocene Fossil, China, Phytotaxa 150 (1), pp. 29-40 : 32-33

Cymbella yangtzensis Li & Metzeltin sp. nov.

Plate 3 , Figures 14–19; holotype specimens is represented in plate 3, figure 14.

Description: Valves dorsiventral, subelliptical-lanceolate, dorsal margin distinctly convex, ventral margin moderately convex to straight. Ends narrowly protracted rostrate and rounded. Length 24.5–33.0 µm; breadth 7.1–8.3 µm, maximal length/breadth ratio about 4.2. Axial area moderately wide, linear, broadening gradually towards the valve center. A central area is absent. Raphe slightly ventrally displaced, terminal fissures dorsally deflected. Striae radiate throughout. Inconspicuous stigmata 5–6 close to the ventral striae in the middle of the central area. Striae in the middle 9–12 in 10 µm (dorsal and ventral side), becoming up to 16 in 10 µm towards the ends.

Holotype: JH 91010-3, Museum of Nanjing Institute of Geography and Limnology, CAS, Nanjing, China

Type locality: Jianghan Palin , Hubei Provice. 30 o 11 ’ 18”N, 112 o 35 ’ 33”E .

Etymology: The Latin name yangtzensis refers to the Yangtze River.

Differential diagnosis: Distinguished from larger sized specimens of the C. affinis Kützing (1844: 80) complex by a “clumsy” shape of all valves, position and number of stigmata, and lacking a central area.

PLATE 3 , Figures 14–19: Cymbella yangtzensis Li & Metzeltin sp. nov. Light microscopy images showing the range of variation

within the type population. Scale bar represents 10 µm.

Figures

PLATE 3, Figures 9–13: Cymbella shii Li sp. nov. Light microscopy images showing the range of variation within the type population. Scale bar represents 10 µm.