Microbregma

Bukejs, Andris & Alekseev, Vitalii I., 2015, A second Eocene species of death-watch beetle belonging to the genus Microbregma Seidlitz (Coleoptera: Bostrichoidea) with a checklist of fossil Ptinidae, Zootaxa 3947 (4), pp. 553-562 : 556

Key to species of the genus Microbregma

1. Abdominal ventrite 1 0.63–0.71 times length of ventrite 2. Body length less than 4.5 mm ............................ 2

- Abdominal ventrite 1 about 0.43 length of ventrite 2. Body length ~ 5.1 mm. Baltic amber............. M. waldwico sp. nov.

2. Body length ~ 3.5 mm. Pronotum as wide as base of elytra. Baltic amber........................ M. sucinoemarginatum

- Body length ~ 3.4–4.5 mm. Pronotum narrower than base of elytra. Recent species...................... M. emarginatum