The Cupedidae are a small family of beetles, notable for the square pattern of "windows" on their elytra, which give the family their common name of reticulated beetles.
Micromalthidae is an ancient family of small beetles belonging to the suborder Archostemata. The only known living representative is the telephone-pole beetle, Micromalthus debilis. A few extinct species have been described, the oldest being the Late Permian Archaeomalthus synoriacos. It is one of the oldest families of beetles still existing today.
The Archostemata are the smallest suborder of beetles, consisting of 50 living species in five families and over 200 described fossil species. They are an ancient lineage with a number of primitive characteristics. Antennae may be thread-shaped (filiform) or like a string of beads (moniliform). This suborder also contains the only beetles where both sexes are paedogenic, Micromalthus debilis. Modern archostematan beetles are considered rare, but were more diverse during the Mesozoic.
The Trachypachidae are a family of beetles that generally resemble small ground beetles, but that are distinguished by the large coxae of their rearmost legs. There are only six known extant species in the family, with four species of Trachypachus found in northern Eurasia and northern North America, and two species of Systolosoma in Chile and Argentina. They were much more diverse in the past, with dozens of described species from the Mesozoic.
Myxophaga is the second-smallest suborder of the Coleoptera after Archostemata, consisting of roughly 65 species of small to minute beetles in four families. The members of this suborder are aquatic and semiaquatic, and feed on algae.
Jurodidae is a family of beetles that was originally described for the extinct genus Jurodes, known from the Middle-Late Jurassic of Asia. In 1996, a living species, Sikhotealinia zhiltzovae was discovered in the Sikhote-Alin mountains in southeastern Siberia, and assigned to this family. Their placement is uncertain, but are usually considered archostematans. In one study, Sikhotealinia and Jurodes were considered a sister group to all other archostematan beetles. However, other authors have considered their placement within beetles as a whole uncertain, due to their mix characteristics of typical Archostemata, as well as Polyphaga and Adephaga.
Scirtoidea is a superfamily of beetles. It is traditionally considered to consist of four families: Clambidae, Decliniidae, Eucinetidae and Scirtidae. However, genetic studies have suggested that Clambidae and Eucinetidae belong to a separate superfamily Clamboidea, which also includes Derodontidae. Scirtoidea and Clamboidea are the two earliest diverging lineages of living polyphagans.
Catiniidae is a small extinct family of beetles known from the Early Triassic to the Early Cretaceous. The family is usually classified as a member of the suborder Archostemata, but beetles in this family had smooth elytra unlike members of the modern-day families Cupedidae and Ommatidae which have elytra with window punctures.
The Ommatidae are a family of beetles in the suborder Archostemata. The Ommatidae are considered the extant beetle family that has most ancestral characteristics. There are only seven extant species, confined to Australia and South America. However, the geographical distribution was much wider during the Mesozoic spanning across Eurasia and Australia, suggesting that they were widespread on Pangea. So far, over 26 extinct genera containing over 170 species of these beetles have been described. Three extant genera have been assigned to this family: Omma,Tetraphalerus and Beutelius. The family is considered to be a subfamily of Cupedidae by some authors, but have been found to be more closely related to Micromalthidae in molecular phylogenies. A close relationship with Micromalthidae is supported by several morphological characters, including those of the mandibles and male genitalia. Due to their rarity, their ecology is obscure, it is likely that their larvae feed on deadwood.
Sphindidae is a family of beetles, in the suborder Polyphaga. They are called slime mold beetles due to their exclusive feeding on slime molds during adult and larval stages, other aspects of their life history are obscure. Palaeontological discoveries since 2015 have added to the geologic history of Sphindidae, including the discovery of Libanopsis, placed in the extinct subfamily Libanopsinae.
Zygadenia is an extinct genus of archostematan beetles from the Jurassic to Cretaceous. It is considered to be a senior synonym of Notocupes by Kirejtshuk (2020), 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.
Omma is a genus of beetles in the family Ommatidae. Omma is an example of a living fossil. The oldest species known, O. liassicum, lived during the final stage of the Triassic (Rhaetian), over 200 million years ago, though the placement of this species in Omma has been questioned. Numerous other fossil species are known from the Jurassic and Cretaceous of Europe and Asia. The only living species is Omma stanleyi, which is endemic to Australia. Three other extant species endemic to Australia that were formerly part of this genus were moved to the separate genus Beutelius in 2020.Omma stanleyi is strongly associated with wood, being found under Eucalyptus bark and exhibiting thanatosis when disturbed. Its larval stage and many other life details are unknown due to its rarity. Males are typically 14–20 mm in length, while females are 14.4-27.5 mm. Omma stanleyi occurs throughout eastern Australia from Victoria to Central Queensland.
Permocupedidae is a family of Protocoleopteran stem group beetles. They first appeared during the Early Permian, and were one of the dominant groups of beetles during the Middle Permian. They became rare in the Late Permian, with only one species known from the Triassic, Frankencupes ultimus from the Middle Triassic (Anisian) Röt Formation of Germany. They are thought to have been xylophagous, which is presumed to be the ancestral ecology of beetles.
Ademosynidae is an extinct family of beetles, known from the Late Triassic to Early Cretaceous. There are at least six genera and 11 species in Ademosynidae. Members of the family were small oval beetles, with a length generally smaller than 1 cm. Characteristics of the family include a pronotum without anterior angles and a rounded anterior margin, and elytra with 9–12 punctate striae. The systematic position of the family within the order Coleoptera is currently uncertain: they can be considered early examples of the suborder Polyphaga, or unusual examples of Archostemata.
Tshekardocoleidae is an extinct family of stem group beetles, known from the Permian. They represent some of the earliest known beetles. They first appeared during the Cisuralian, before becoming extinct at the beginning of the Guadalupian. A claimed Jurassic record is doubtful. Like other primitive beetles, they are thought to have been xylophagous. The oldest known beetle, Coleopsis, was originally assigned to this family, but is now assigned to its own family Coleopsidae.
Taldycupedidae is an extinct family of beetles primarily known from the Permian period.
Coleopterida is a superorder of insects consisting of the orders Coleoptera and Strepsiptera. It is established as the sister group of Neuropterida based on phylogenetic analysis of DNA sequence data. The grouping is also supported by morphological data. The Coleopterida are estimated to have first appeared during the Carboniferous period, but the earliest confirmed fossils of the group date to the Permian. The Carboniferous insect species Stephanastus polinae has been interpreted by some authors as the sister group of Coleoptera and Strepsiptera, but this interpretation has been disputed and it has been alternatively suggested to be a member of the extinct order Protelytroptera.
Lepidomma is an extinct genus of ommatid beetle. The genus was first described in 2019 for the species L. tianae. Lepidomma was synonymised with Clessidromma by Kirejtshuk, 2020. This synonymy was disputed by Li et al. (2021), who maintained Lepidomma as a separate genus from Clessidromma. Three additional species of Lepidomma were described in 2020 and 2022. All four species are known from the Cenomanian aged Burmese amber of Myanmar.
Notocupes is an extinct genus of medium-sized archostematan beetles from the Mesozoic Era of Eurasia, including over 50 described species. Historically, the genus was classified as a member of the family Ommatidae, but the presence of characters such as the horizontal mandibular cutting edge, separated procoxae and overlapping abdominal sternites indicate that the genus may have a closer affinity with the family Cupedidae. Notocupes is considered to be a junior synonym of Zygadenia by Kirejtshuk (2020), 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. Most species of Notocupes were described from compression fossils. An additional three species were described from Cenomanian-aged Burmese amber, which were treated as a separate genus, Echinocups, by Kirejtshuk (2020), but Li et al. (2023) consider Echinocups to be a junior synonym of Notocupes. Notocupes has a flattened body, which may suggest that it occupied narrow habitats, such as living under bark. Some species had serrated/spined margins of the carapace, which may have served as a defense against predators, or served as camouflage to resemble bark.
