APPENDIX 1.

Key to extinct Lamprosomatinae (modified from Bukejs and Nadein, 2015)

(1) Vertex with longitudinal median groove; frons with groove at inner and upper margins of eye; compound eyes with inner margin slightly emarginated; prohypomera concave on whole surface; legs strongly flattened 2

- Vertex without longitudinal median groove; frons without groove at inner and upper margins of eye; eyes entire, not notched; prohypomera concave in posterior one-third; legs slightly flattened 3

(2) Tarsal claws appendiculate with denticle basally; pronotal lateral margins with bordering; epipleura with strong projection in basal one-third; larger, body length 4.1 mm
Damzenius anitae

- Tarsal claws simple; pronotal lateral margins without bordering; epipleura with weak projection in basal one-third; smaller, body length 3.2 mm... Succinoomorphus warchalowskii

(3) Legs shorter, tibiae more widened apically; eyes large; elytral punctures smaller, punctures distinctly arranged in rows inter-mixed by fine and obscure punctures between them, punctural rows regular Archelamprosomius balticus

- Legs longer, tibiae not widened apically; eyes small; elytral punctures larger and subuniform, punctural rows confused Archelamprosomius kirejtshuki