Coptoclavidae

Coptoclavidae is an extinct family of aquatic beetles in the suborder Adephaga. The Coptoclavidae lived from the Late Triassic to the Early Cretaceous. Coptoclavidae is a member of the adephagan clade Dytiscoidea, which contains living aquatic beetles, including living predatory diving beetles (Dytiscidae). Coptoclavids are thought to have hunted on the water surface, similar to whirligig beetles (Gyrinidiae), with prey likely including small fish and larval amphibians. Suggested reasons for their extinction to include the rise of teleost fish, or competition with Gyrinidae and Dytiscidae, which possess defensive secretions and sucking channels in the mandibles of larvae, which coptoclavids likely lacked. It has been suggested that the genus Timarchopsis and the subfamily Timarchopsinae are only distantly related to other coptoclavids based on cladistic analysis, with Timarchopsis being more closely related to geadephagans like carabids and trachypachids instead. Another study also suggested similarly for Coptoclavisca and possibly other coptoclaviscines. A 2025 study suggested that Coptoclavidae as a whole, as well as most of the major subfamilies, were likely not monophyletic, but represent a number of separate lineages of dytiscoid beetles.

== Taxonomy == †Agrascapha – Huangshanjie Formation, China, Carnian †Amblycephalonius – Posidonia Shale, Germany, Toarcian subfamily †Charonoscaphinae †Charonoscapha – Karabastau Formation, Kazakhstan, Callovian †Charonoscaphidia – Karabastau Formation, Kazakhstan, Callovian †Coptoclavia – Cassange Group, Upper Triassic subfamily †Coptoclavinae †Bolbonectes †Bolbonectes intermedius – Byankino Formation, Russia, Tithonian; Leskovskaya Formation, Russia, Barremian †Bolbonectes occidentalis – Ichetuy Formation, Russia, Oxfordian †Bolbonectus lithographicus – La Pedrera de Rúbies Formation, Spain, Barremian †Coptoclava – Ustkarskaya Formation, Russia, Hauterivian; Dabeigou Formation, China, Hauterivian; Kutinskaya Formation, Russia, Barremian; Dalazi Formation, Laiyang Formation, Jianchang Formation, Shouchang Formation, Jiufotang Formation, Chijinbao Formation, Aptian; Zaza Formation, Gidarinskaya Formation, Mangutskaya Formation, Turga Formation, Russia, Aptian, Jinju Formation, South Korea, Albian †Hoyaclava – Las Hoyas, Spain, Barremian †Megacoptoclava – Las Hoyas, Spain, Barremian subfamily †Coptoclaviscinae †Coptoclavella †Coptoclavella elegans – Mogotuin Formation, Mongolia, Aptian †Coptoclavella inexpecta – La Pedrera de Rúbies Formation, Spain, Barremian †Coptoclavella jurassica – Sharteg, Mongolia, Tithonian †Coptoclavella minor – Takshin Formation, Kalgan Formation Russia, Callovian; Daya Formation, Russia, Hauterivian; Mogotuin Formation, Mongolia, Aptian; Turga Formation, Russia, Aptian †Coptoclavella purbeckensis – Durlston Formation, United Kingdom, Berriasian †Coptoclavella vittata – Gurvan-Eren Formation, Mongolia, Aptian †Coptoclavella striata – Gurvan-Eren Formation, Mongolia, Aptian †Coptoclavisca – Laiyang Formation, China, Aptian; Tsagaantsav Formation, Mongolia, Early Cretaceous †Holcoptera (= Stargelytron ) †Holcoptera alisonae – Charmouth Mudstone Formation, United Kingdom, Sinemurian †Holcoptera altus () (= Stargelytron altus ) – Röt Formation, Germany, Anisian †Holcoptera giebeli – Lilstock Formation, United Kingdom, Rhaetian; Charmouth Mudstone Formation, United Kingdom, Sinemurian †Holcoptera larissae () (= Stargelytron larissae ) – Hassberge Formation, Germany, Carnian †Holcoptera pigmentatus – Lilstock Formation, United Kingdom, Rhaetian; Portland Formation, Connecticut, Hettangian; Mount Toby Formation, Massachusetts, Hettangian †Holcoptera rasnitsyni – Protopivka Formation, Ukraine, Norian †Holcoptera schlotheimi (=Holcoptera confluens ) – Argilliti di Riva di Solto Formation, Italy, Norian; Lilstock Formation, United Kingdom, Rhaetian; Blue Lias, United Kingdom, Hettangian; Portland Formation, Connecticut, Hettangian †Holcoptera solitensis – Cow Branch Formation, North Carolina, Norian †Euroscapha – Huangshanjie Formation, China, Carnian subfamily †Hispanoclavinae †Hispanoclavina – Las Hoyas, Spain, Barremian subfamily †Timarchopsinae †Actea – Solnhofen, Germany, Tithonian †Daohugounectes – Daohugou, China, Callovian †Ditomoptera – Solnhofen, Germany, Tithonian †Exedia – Karabastau Formation, Kazakhstan, Callovian †Ovonectes – Las Hoyas, Spain, Barremian †Protonectes – Hassberge Formation, Germany, Carnian †Pseudohydrophilus – Solnhofen, Germany, Tithonian †Stygeonectes – Cheremkhovskaya Formation, Russia, Toarcian; Udinskaya Formation, Russia, Callovian; Uda Formation, Ichetuy Formation, Russia, Oxfordian; Glushkovo Formation, Russia, Tithonian; Leskovskaya Formation, Bukachacha Formation, Russia, Barremian; Godymboyskaya Formation, Turga Formation, Russia, Aptian †Timarchopsis †Timarchopsis aquaticus – Cheremkhovskaya Formation, Russia, Toarcian; Ichetuy Formation, Russia, Oxfordian †Timarchopsis cyrenaicus – Algeria, Hauterivian †Timarchopsis czekanowskii – Cheremkhovskaya Formation, Russia, Toarcian †Timarchopsis gigas – Karabastau Formation, Kazakhstan, Callovian †Timarchopsis gobiensis – Ulaan-Ereg Formation, Mongolia, Tithonian †Timarchopsis latus – Sagul Formation, Kyrgyzstan, Toarcian †Timarchopsis longus – Sharteg, Mongolia, Tithonian †Timarchopsis mongolicus – Zhargalant Formation, Mongolia, Bathonian †Timarchopsis sainshandensis – Khamarkhoburinskaya Formation, Mongolia, Aalenian †Tuhanectes – Sanjianfang Formation, China, Bathonian