Omma

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Omma
Temporal range: Rhaetian–Recent
Omma stanleyi CCAL3.0.jpg
Omma stanleyi
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Ommatidae
Genus: Omma
Newman, 1839
Type species
Omma stanleyi
Newman, 1839
Synonyms
  • ProcarabusOppenheim, 1888
  • ChalepocarabusHandlirsch, 1906
  • PyrochroophanaHandlirsch, 1906
  • OmmamimaPonomarenko, 1964
  •  ? Cionocups Kirejtshuk, 2020

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. [1] 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. [2] 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. [2]

Contents

Description

According to Li, Huang & Cai, 2021, Omma is distinguished from other ommatid beetles by the following characters: [1]

Head without prominent posterior protuberances. Labrum with dentate anterior margin. Separate mentum absent. Anterior third of gulamentum not depressed. Pronotal disc with rounded lateral edges; dorsal surface without ridges or protuberances. Sternopleural suture absent. Prosternal process short. Punctured explanate elytral epipleura absent. CuA of hind wings forked; wedge cell present. Abdominal ventrites abutting.

Species, temporal and spatial distribution

The following extinct and extant species have been described. [3] [4] [5]

Taxa labelled (?) are considered questionable by Kirejtshuk, 2020

Omma stanleyi Newman, 1839 (type), recent, Australia

Fossil species

Related Research Articles

<span class="mw-page-title-main">Cupedidae</span> Family of beetles

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.

<span class="mw-page-title-main">Jurodidae</span> Family of beetles

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.

<span class="mw-page-title-main">Ommatidae</span> Family of beetles

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.

Brochocoleus is an extinct genus of beetles in the family Ommatidae, known from the Early Jurassic to the Early Late Cretaceous. 9 species are currently recognised, with many species being reassigned to other genera by Kirejtshuk's major systematic revision in 2020.

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.

<i>Tetraphalerus</i> Genus of beetles

Tetraphalerus is a genus of beetles in the family Ommatidae, It is currently known from two extant species native to South America and several fossil species from the Jurassic and Cretaceous of Asia.

<span class="mw-page-title-main">Protocoleoptera</span> Extinct suborder of beetles

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.

<i>Allophalerus</i> Extinct genus of beetles

Allophalerus is an extinct genus of beetle in the family Ommatidae. It is known from nine species formerly included in the genus Tetraphalerus.

<i>Bukhkalius</i> Extinct genus of beetles

Bukhkalius is an extinct genus of beetle belonging to the family Ommatidae, it contains the single species, Bukhkalius lindae. It was described in 2017 initially as a species of the extant genus Tetraphalerus and was placed into a separate monotypic genus in 2020, which was reaffirmed in a 2021 study. It is known from a single specimen from Burmese amber, dating to the Cenomanian stage of the Late Cretaceous. The specimen is around 4.7 mm long and around 1.3 mm wide.

<i>Burmocoleus</i> Extinct genus of beetles

Burmocoleus is an extinct genus of archostematan beetle belonging to the family Ommatidae. It is known from two species, Burmocoleus zhiyuani, which was initially assigned to the genus Brochocoleus. This species was placed into the new genus Burmocoleus by Kirejtshuk, 2020, who also described a new species, Burmocoleus prisnyi. Both species are known from the Cenomanian aged Burmese amber from Myanmar. Similar to Stegocoleus, Brochocoleus and Jarzembowskiops it has flat, wide elytral edges, but can be distinguished from these genera in several characters, and is more similar to other ommatids in the characters of the prothorax.

<i>Cionocups</i> Extinct genus of beetles

Cionocups is an extinct genus of ommatid beetle. It is known from a single species, Cionocups manukyani, found in Cenomanian aged Burmese amber from Myanmar. It was originally considered to be closely related to the genus Cionocoleus, but it is considered a junior synonym of Omma by some subsequent authors.

<i>Clessidromma</i> Extinct genus of beetles

Clessidromma is an extinct genus of ommatid beetle. It currently contains a single species Clessidromma palmeri, known from the Cenomanian aged Burmese amber of Myanmar. Kirejtshuk (2020) synonymised Lepidomma with Clessidromma and included two additional species in the latter: C. tianae, originally the type species of Lepidomma, and C. zengi, a newly described species. Li et al. (2021) disputed the synonymy of Lepidomma with Clessidromma, maintaining Lepidomma as a separate genus, and transferred C. zengi to a new genus, Kirejtomma, in 2021.

Echinocups is an extinct genus of ommatid beetle. It was created in 2020 to house three species originally assigned to Notocupes, E. denticollis, E. neli and E. ohmkuhnlei The genus name refers to the sharp spikes present on the elytra. All three species are known from the Cenomanian aged Burmese amber of Myanmar. The status of Echinocups as a distinct genus was contested by Li et al. (2023), who considered the genus Echinocups to be a junior synonym of the genus Notocupes.

<i>Paraodontomma</i> Extinct genus of beetles

Paraodontomma is an extinct genus of ommatid beetle, it is known from three species, P. burmiticum described in 2017, P. szwedoi described in 2018. and P. leptocristatum in 2021. All 3 species are known from the Cenomanian aged Burmese amber.

Stegocoleus is an extinct genus of ommatid beetle. Its distinctive morphology includes a distinctive flat rim on the outer edge of the elytra similar to those of Burmocoleus and Jarzembowskiops, but is distinguished from those genera by a distinctive prothorax. It is known from 3 species found in Cenomanian aged Burmese amber.

Liassocupes is an extinct genus of ommatid beetle from the Jurassic period of England. The only species is Liassocupes parvus. It is known from compression fossils found at Flatstones near Charmouth in the Sinemurian aged part of the Charmouth Mudstone Formation, Dorset Other species previously assigned to the genus include Liassocupes (?) maculatus described by Whalley in 1985 from the same locality, but this was subsequently suggested by Ponomarenko to belong to either Omma or Tetraphalerus and was considered to belong to the genus Brochocoleus by Kirejtshuk, 2020. Another species Liassocupes (?) giganteus also described by Whalley 1985 from the same locality, was found to be a member of the genus Mimemala in the extinct family Schizocoleidae.

<i>Miniomma</i> Extinct genus of beetles

Miniomma is an extinct genus of ommatid beetle. It is known from a single species, Miniomma chenkuni, from the Cenomanian aged Burmese amber from Myanmar. The species is the smallest known ommatid, at less than 2 mm long, compared to Omma, which ranges in length from 6 to 26 mm.

<i>Kirejtomma</i> Extinct genus of beetles

Kirejtomma is an extinct genus of ommatid beetle, known from the early Late Cretaceous (Cenomanian) aged Burmese amber of Myanmar. The type and only known species K. zhengi was described in 2020 as a species of Clessidromma, and placed into the new genus in 2021.

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.

<i>Notocupes</i> Extinct genus of beetles

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.

References

  1. 1 2 3 Li, Yan-Da; Huang, Di-Ying; Cai, Chen-Yang (2021-11-30). "New species of Omma Newman from mid-Cretaceous Burmese amber (Coleoptera, Archostemata, Ommatidae)". Deutsche Entomologische Zeitschrift. 68 (2): 341–348. doi: 10.3897/dez.68.74174 . ISSN   1860-1324. S2CID   244783528.
  2. 1 2 Escalona, Hermes E.; Lawrence, John F.; Ślipiński, Adam (2020-01-24). "The extant species of the genus Omma Newman and description of Beutelius gen. nov. (Coleoptera: Archostemata: Ommatidae: Ommatinae)". Zootaxa. 4728 (4): 547–574. doi:10.11646/zootaxa.4728.4.11. ISSN   1175-5334. PMID   32229891. S2CID   212766123.
  3. Ommatidae Species List Archived 2012-10-23 at the Wayback Machine at Joel Hallan’s Biology Catalog. Texas A&M University. Retrieved on 11 May 2012.
  4. Tan, Jingjing; Wang, Yongjie; Ren, Dong; Yang, Xingke (2012). "New fossil species of ommatids (Coleoptera: Archostemata) from the Middle Mesozoic of China illuminating the phylogeny of Ommatidae". BMC Evolutionary Biology. 12: 113. doi: 10.1186/1471-2148-12-113 . PMC   3518168 . PMID   22776212.
  5. Kirejtshuk, Alexander G. (2020-02-17). "Taxonomic Review of Fossil Coleopterous Families (Insecta, Coleoptera). Suborder Archostemata: Superfamilies Coleopseoidea and Cupedoidea". Geosciences. 10 (2): 73. Bibcode:2020Geosc..10...73K. doi: 10.3390/geosciences10020073 . ISSN   2076-3263.
  6. Jarzembowski, Edmund A.; Zheng, Daran; Zhao, Xianye (2021-11-12). "Is the beetle Omma (Insecta: Coleoptera) a living fossil?". Geological Society, London, Special Publications. 521: SP521–2021–56. doi:10.1144/SP521-2021-56. ISSN   0305-8719. S2CID   244091355.