Suchonellina

Internal mould of left valve of Suchonellina parallela, from Kukhtinov et al. (2008).

Belongs within: Cypridocopina.

Suchonellina is a genus of freshwater ostracods known from the Upper Permian. Valves are an elongate oval in shape with the posterior end sharply produced ventrally (Benson et al. 1961).

Characters (from Benson et al. 1961): Length 0.5 to 0.7 mm, height 0.25 to 0.3 mm. Elongate oval, anterior end blunt, posterior end sharply produced below; left valve larger than right valve, overlapping it on ventral and posterior margins; dorsal margin straight or slightly convex; ventral margin straight or slightly concave; valves very strongly inflated, with greatest convexity closer to posterior than anterior edge; in dorsal view rear edge blunter than front edge. Muscle imprint in front half of valves, from interior appearing as small rounded convexity, from centre of which radiate little ridges and depressions; hinge a cylindrical groove on right valve and bar on left valve; hinge edge of right valve only loosely overlapping left valve.

<==Suchonellina Spizharsky 1937 BB61
    |--*S. inornata (M’Coy & Jones 1850) [=Cythere (Cytherella) inornata] BB61
    |--S. anjigensis TT05
    |--S. compacta TT05
    |--S. cultella TT05
    |--S. daedala TT05
    |--S. futschiki TT05
    |--S. parallela TT05
    |--S. spizharskii TT05
    |--S. trapezoida TT05
    |--S. undulata TT05
    `--S. yanichevski BB61

*Type species of generic name indicated

REFERENCES

[BB61] Benson, R. H., J. M. Berdan, W. A. van den Bold, T. Hanai, I. Hessland, H. V. Howe, R. V. Kesling, S. A. Levinson, R. A. Reyment, R. C. Moore, H. W. Scott, R. H. Shaver, I. G. Sohn, L. E. Stover, F. M. Swain & P. C. Sylvester-Bradley. 1961. Systematic descriptions. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt Q. Arthropoda 3: Crustacea: Ostracoda pp. Q99–Q421. Geological Society of America and University of Kansas Press.

[TT05] Tverdokhlebov, V. P., G. I. Tverdokhlebova, A. V. Minikh, M. V. Surkov & M. J. Benton. 2005. Upper Permian vertebrates and their sedimentological context in the South Urals, Russia. Earth-Science Reviews 69: 27–77.

Last updated: 28 September 2020.