Key to species of the genus Piesocorynus in Dominican and Mexican amber.

1. Elytron with tubercles on third interval 2
  - Elytron without tubercles on third interval 4
2. Elytron with one tubercle at base of second and third intervals --- P. unibullus sp. nov.  
  - Elytron with two or three tubercles on third interval 3
3. Elytron with two tubercles on third interval: one at base and one in middle P. bibullus sp. nov.
  - Elytron with three tubercles: one at base of second and third intervals, one in middle and one before apex of third interval P. tribullus sp. nov.
4. Antennae long, extending beyond humeri 5
  - Antennae short, not reaching, or reaching humeri 6
5. Elytra short. Pronotum elongate with sides evenly rounded P. brevitectus sp. nov.
  - Elytra elongate. Pronotum short with sides angular in middle P. hamus sp. nov.
6. Pronotum elongate. Elytra 1.4 times as long as pronotum P. elongatus sp. nov


  - Pronotum short. Elytra 1.6-2.0 times as long as pronotum 7
7. Elytra approximately equal in length and width P. parategus sp. nov.
  - Elytra considerably longer than wide (1.3-1.4 times) 8
8. Body size large (4.8 mm). Punctures in striae of elytra large. Pronotum slightly longer than wide. P. villosus sp. nov.
  - Body size smaller (2.5 mm). Punctures in striae of elytra fine. Pronotum transverse P. parvocorpus sp. nov.