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.[2]

Protocoleoptera
Temporal range: Asselian–Anisian
(A, B) Moravocoleus permianus (Tshekardocoleidae) (C,D) Permocupes sojanensis (Permocupedidae) (E) Tshekardocoleidae, Sylvacoleus richteri (F) Taldycupedidae, Taldycupes reticulatus
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Suborder: Protocoleoptera
Tillyard, 1924[1]
Families

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Nomenclature

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Protocoleoptera was originally proposed by Robert John Tillyard in 1924 for the extinct genus Protocoleus, assigned to the family Protocoleidae. Protocoleus is now considered a member of the extinct order Protelytroptera (a stem-group of the modern Dermaptera, the earwigs), which would make Protocoleoptera in this sense a synonym of the order.[3] Roy Crowson later reused the name "Protocoleoptera" to refer to Early Permian beetles such as the Tshekardocoleidae, while establishing the Archecoleoptera for Late Permian beetles.[4] Because Protocoleoptera in its original sense is a synonym of Protelytroptera, Cai et al. (2022) proposed a replacement name, Alphacoleoptera Engel, Cai & Tihelka, 2022.[5] Some authors reject the use of Protocoleoptera and Archecoleoptera and include their members within a broad concept of the suborder Archostemata instead.[3][6]

Taxonomy

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The taxonomic naming scheme of early beetles currently has no consensus, with several separate classification schemes proposed for higher level-clades within the stem-group.[5][7] It is generally agreed that Tshekardocoleidae is the earliest diverging group among the major families.[2][7]

References

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  1. ^ Tillyard, R.J. (1924). "Upper Permian Coleoptera and a new order from the Belmont Beds, New South Wales". Proceedings of the Linnean Society of New South Wales. 49: 429–435.
  2. ^ a b Zhao, Xianye; Yu, Yilun; Clapham, Matthew E; Yan, Evgeny; Chen, Jun; Jarzembowski, Edmund A; Zhao, Xiangdong; Wang, Bo (2021-11-08). Perry, George H; Fikacek, Martin (eds.). "Early evolution of beetles regulated by the end-Permian deforestation". eLife. 10: e72692. doi:10.7554/eLife.72692. ISSN 2050-084X. PMC 8585485. PMID 34747694.
  3. ^ a b Alexander G. Kirejtshuk; Markus Poschmann; Jakub Prokop; Romain Garrouste; André Nel (2014). "Evolution of the elytral venation and structural adaptations in the oldest Palaeozoic beetles (Insecta: Coleoptera: Tshekardocoleidae)". Journal of Systematic Palaeontology. 12 (5): 575–600. Bibcode:2014JSPal..12..575K. doi:10.1080/14772019.2013.821530. S2CID 85163674.
  4. ^ Crowson, R.A. (1981). "Chapter 20: Evolutionary History of Beetles". The Biology of the Coleoptera (PDF). London: Academic Press. pp. 658–688.
  5. ^ a b Cai, C.; Tihelka, E.; Giacomelli, M.; Lawrence, J.F.; Ślipiński, A.; Kundrata, R.; Yamamoto, S.; Thayer, M.K.; Newton, A.F.; Leschen, R.A.B.; Gimmel, M.L.; Lü, L.; Engel, M.S.; Bouchard, P.; Huang, D.; Pisani, D.; Donoghue, P.C.J. (2022). "Integrated phylogenomics and fossil data illuminate the evolution of beetles". Royal Society Open Science. 9 (3): 211771. Bibcode:2022RSOS....911771C. doi:10.1098/rsos.211771. PMC 8941382. PMID 35345430.
  6. ^ 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.
  7. ^ a b Boudinot, Brendon Elias; Yan, Evgeny Viktorovich; Prokop, Jakub; Luo, Xiao-Zhu; Beutel, Rolf Georg (2022-07-28). "Permian parallelisms: Reanalysis of †Tshekardocoleidae sheds light on the earliest evolution of the Coleoptera". Systematic Entomology. 48: 69–96. doi:10.1111/syen.12562. ISSN 0307-6970. S2CID 251171914.