Trophi. A–G Morphology of the ramus (“unci”) teeth A teeth absent (S. pectinata) B teeth absent, margin slightly corrugated (S. stylata) C no distinct teeth, only a serrated plate, frontal hook with a spine (arrow; S. vorax) D one to two teeth are sharply pointed and remainder are blunt (S. verrucosa) E teeth distinctly incised, frontal hook with a spine (S. gyrina) F dorsal teeth distinctly incised and ventral comb-like (S. triophthalma) G dorsal teeth comb-like and ventral distinctly incised, frontal hook with a spine (arrow; S. baltica) H–J Shape and breadth (double headed-arrow) of the lateral fulcrum H blade-like, narrow, distal end not oblique (S. tremula) I machete-like, narrow, distal end oblique (dashed arrows; S. oblonga) J axe-shaped to semi-circular, broad to very broad, distal end oblique (dashed arrows; S. longipes) K–L Shape of the hypopharynx K small to medium, robust (S. tremula) L broad to very broad, laterally pointed / dagger-like (S. stylata) M–R Shape of the cauda of the manubrium M of even width (S. baltica) N slightly decreasing distally (S. pectinata) O with a small knob-like thickening distally (S. hutchingsi) P with a large knob-like thickening distally (S. grimpei) Q oar blade shaped at the distal half (S. oblonga) R cauda spatulate or kinked distally (S. glacialis). Drawings modified from: D Stemberger (1979) (sub. S. asymmetrica Koch-Althaus) and Jersabek et al. (2003a) R Friedrich and De Smet (2000).