Beetles are insects that form the order Coleoptera, in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 described species, is the largest of all orders, constituting almost 40% of described insects and 25% of all known animal species; new species are discovered frequently, with estimates suggesting that there are between 0.9 and 2.1 million total species. However, the number of beetle species is challenged by the number of species in dipterans (flies) and hymenopterans (wasps).
Spercheus is a genus of aquatic beetles which are placed in a family of their own, Spercheidae within the Hydrophiloidea. About 20 species are known from around the world except the Nearctic with the majority being from the Oriental and Afrotropical Realms.
The telephone-pole beetle is a beetle native to the eastern United States and the only known living representative of the otherwise extinct family Micromalthidae. Larvae of the beetle live in decaying wood and can be pests to wooden structures, lending them their common name, the 'telephone-pole beetle.'
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.
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.
Corylophidae is a family of minute hooded beetles, sometimes called minute fungus beetles, in the superfamily Coccinelloidea. There are about 18 genera and at least 120 described species in Corylophidae. They feed on microfungi such as molds, and are often found associated with bark, as well as in leaf litter and other decaying vegetation. In older literature, the family name was often given as Orthoperidae.
Adinolepis is a genus of beetles in the family Cupedidae containing four species, all endemic to Australia. A fifth species, Adinolepis scalena, was transferred to Ascioplaga in 2009.
Priacma is a genus of beetles in the family Cupedidae. It contains a single extant species, Priacma serrata native to western North America and one fossil species, P. megapuncta from the Cenomanian aged Burmese amber. Species previously assigned to the genus from the Yixian Formation of China have been subsequently placed in the separate genus Apriacma.
Rhipsideigma is a genus of beetles in the family Cupedidae. It contains five species, four of which are endemic to Madagascar, the other being endemic to the northern coast of Tanzania. They vary in length from 13 mm to 20 mm, and are up to 6 mm wide.
Tenomerga is a genus of beetles in the family Cupedidae. This genus has about 17 extant species, which are native to the eastern Palearctic, Nearctic and Oriental regions.
Paracupes is a genus of beetles in the family Cupedidae, the reticulated beetles.
Crowsoniella is a genus of beetles in the order Archostemata. It contains only a single species, Crowsoniella relicta, and is the only member of the monotypic family Crowsoniellidae. It is known only from three male specimens collected in 1973 in the Lepini mountains of central Italy by Roberto Pace. In a degraded pasture, the beetles were found among the roots of a large hawthorn tree, in deep calcareous soil. No other specimens have been found since.
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.
Prionoceridae is a small family of beetles, in the suborder Polyphaga. They form a group within the cleroid beetles and were formerly treated as a subfamily (Prionocerinae) within the family Melyridae. Very little is known of their life history but most species are pollen feeders as adults and occur in large numbers during spring or the host flowering season. Larvae are predatory or feed on decomposing wood.
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.
The Protocoleoptera are a paraphyletic group of extinct beetles, containing the earliest and most primitive lineages of beetles. They represented the dominant group of beetles during the Permian, but were largely replaced by modern beetle groups during the following Triassic. Protocoleopterans typically possess prognathous (horizontal) heads, distinctive elytra with regular window punctures, culticles with tubercles or scales, as well as a primitive pattern of ventral sclerites, similar to the modern archostematan families Ommatidae and Cupedidae. They are thought to have been xylophagous and wood boring.
Magnocoleus is an extinct genus of beetles from the Early Cretaceous of China, between 130.0 and 125.45 Mya. The genus contains a single species, Magnocoleus huangjiapuensis, and is the only member of the family Magnocoleidae in the suborder Archostemata. Magnocoleus was first described by Chinese palaeoentomologist Hong Youchong in 1998, based on fossils of isolated elytra from the Qingshila Formation in Huangjiapu, near the Nantianmen village of Zhangjiakou in Hebei. Recent phylogenetic analyses have suggested that Magnocoleus is closely related to or placed within either Cupedidae or Ommatidae.
Gyrininae is a subfamily of ground and water beetles in the family Gyrinidae. There are at least 740 described extant species in Gyrininae.
2017 in paleoentomology is a list of new fossil insect taxa that were described during the year 2017, as well as other significant discoveries and events related to paleoentomology that were scheduled to occur during the year.
Burmese amber is fossil resin dating to the early Late Cretaceous Cenomanian age recovered from deposits in the Hukawng Valley of northern Myanmar. It is known for being one of the most diverse Cretaceous age amber paleobiotas, containing rich arthropod fossils, along with uncommon vertebrate fossils and even rare marine inclusions. A mostly complete list of all taxa described up to the end of 2023 can be found in Ross (2024).
