Type and only species: Vesperalia perplexa Valiukevičius, 2004; Lithuania, Stoniškiai−1 borehole, depth 1211–1217 m; Upper Silurian, Pridoli, Rietavas Beds, Jûra Formation.

Diagnosis.—Vesperaliid acanthodian with high−crowned scales having pores around the neck and a crown plate with a sculpture of four to six linear or slightly wavy ridges, of which two converging ones may form lowly raised medial area; ridges extend the entire crown length or fade out mid−length, reemerging on the posterior edge of the crown behind a smooth area. Scales grew superpositionally or both superpositionally and areally. The stranggewebe with unusually large oriented lacunae and odontocytic mesodentine (only in narrow outer layers of growth zones) form both posterior and anterior parts of the crown; the crown has a system of widened and multiply branched ascending dentinal canals plus radial canals at the base/crown junction.