Zygadenia

Zygadenia is an extinct genus of archostematan beetles from the Early Jurassic to Early Cretaceous. It is considered to be a senior synonym of Notocupes by Kirejtshuk, but other researchers suggest to reserve the genus Zygadenia as a form taxon for isolated elytra that probably belong to the genus Notocupes, while retaining Notocupes as a valid genus for complete body fossils.
Eleven species are included in the genus, after Strelnikova and Yan. Kirejtshuk notes that the two Lower Jurassic Australian species Z. westraliensis and Z. martinae possibly merit placement in their own separate genus.

Jurassic species

[Hettangian]-[Toarcian] (201.4 Ma to 174.7 Ma)

Xiaomeigou Formation, ChinaZ. haixiensis Song et al., 2024

[Sinemurian]-[Toarcian] (199.5 Ma to 174.1 Ma)

;Cattamarra Coal Measures, AustraliaZ. martinae

''Z. westraliensis''

[Tithonian] (152.1 Ma To 145.0 Ma)

;Shar Teeg, MongoliaZ. giebeli

''Z. handlirschi''

Cretaceous species

[Berriasian] (145.0 Ma To 139.8 Ma)

;Lulworth Formation, United KingdomZ. angliae

''Z. tuberculata''

[Hauterivian] (132.9 Ma to 129.4 Ma)

;Weald Clay, United KingdomZ. angliae Z. floodpagei

''Z. simpsoni''

[Barremian] (129.4 Ma to 125.0 Ma)

;Sinuiju Formation, North KoreaZ. liui
;Weald Clay, United KingdomZ. angliae Z. floodpagei Z. tuberculata

''Z. simpsoni''

[Aptian] (125.0 to ~113.0 Ma)

;Argun Formation, RussiaZ. sinitzae
;Sinuiju Formation, North KoreaZ. liui
;Yixian Formation, ChinaZ. liui
;Zaza Formation, Buryatia, Russia

''Z. alexrasnitsyni''

[Albian] (113.0 Ma to 100.5 Ma)

;Jinju Formation, South Korea

''Z. cornigera''