Jinju Formation
Introduction The '''Jinju Formation''' () is an Early Cretaceous geologic formation in South Korea. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus. The depositional age of this formation spans from approximately 112.4 ± 1.3 to 106.5 million years ago (early Albian) based on detrital zircon U-Pb dating. It predominantly consists of black shale, with sandstone packets, deposited in a fluvial-lacustrine setting.A diverse spider fauna is known from the formation, including indeterminate mygalomorphs and palpimanoids as well as two species of lagonomegopid belonging to the genera ''Koreamegops'' and ''Jinjumegops''. Other compression fossils known from the formation include a species of the zhangsolvid fly ''Buccinatormyia'', the elaterid beetle ''Koreagrypnus'', and the ichthyodectiform fish ''Jinjuichthys''. This formation has also "attracted global ichnological attention" for the variety of important ichnofossils. Columnar and rod-shaped stromatolites have also been found here.
Fossil content === Flora ===+Plants of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Cupressinocladus''''C.'' sp.The presence of this conifer indicates that mixed-type flora existed in this formation.''Ruffordia''''R''. sp.Schizaeaceae ferns''Cladophlebis''''C''. sp.''Sphenopteris''''S''. sp.''Onychiopsis''''O. elongata''leptosporangiate ferns''Brachyphyllum''''B. japonicum''=== Spiders ===+Spiders of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Korearachne''''K. jinju''likely to be a lycosoid''Koreamegops''''K. samsiki''a lagonomegopid''Jinjumegops''''J. dalingwateri''a lagonomegopidMygalomorphaeindeterminateAraneomorphaeindeterminatePalpimanoideaindeterminate"Cribellate Entelegynae"* "species 1"* "species 2"=== Insects ===Jinju formation consists of a diverse order of insects: Orthoptera, Homoptera, Mantodea, Diptera, Coleoptera, Hymenoptera, Dermaptera, Neuroptera, Blattoidea, Hemiptera, Odonata, Mecoptera, etc. A larvae fossil of aquatic insect has also been discovered.==== Orthoptera ====+'''Orthopterans of the Jinju Formation''''''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Panorpidium''''P. spica''A member of Elcanidae==== Odonata ====+'''Dragonflies of the Jinju Formation''''''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Hemeroscopus''''H. baissicus''==== Hymenoptera ===='''Hymenopterans of the Jinju Formation''''''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Korehelorus'' ''K. jinjuensis'' A parasitic wasp belonging to the family Heloridae''Hanguksyntexis'' ''H. haeretica'' A sawfly belonging to the family Anaxyelidae==== Raphidioptera ====+Snakeflies of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Mesoraphidia''* ''M. koreensis''* ''M. phantasma''A member of Mesoraphidiidae==== Blattodea ====+Cockroaches of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Rhipidioblattina''* ''R. sp. cf. R. radipinguis''* ''R?. sp. cf. R. jilinensis''* ''R. sp.'' A''Mesoblattina''* ''M. sp.'' A* ''M. sp.'' B* ''M. sp.'' C* ''M. sp.'' D''Samaroblatta''''S. sp. cf. S. rhypha''''Blattula''* ''B. sp. cf. B. exetenuata''* ''B. sp.'' A''Mesoblattula''''M. sp. ''IndeterminateA total of 13 indeterminate species==== Coleoptera ====+Beetles of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Coptoclava''''C. sp''Both nymph and adult fossils foundA member of the extinct family Coptoclavidae. Similar to ''C. longipoda'', but assigned to a yet undescribed species since ''C. longipoda'' is usually considered to be a species complex.thumb''Megalithomerus''''M. magolhalmii''A member of Elateridae''Koreagrypnus''''K. jinju''''Cretosaja''''C. jinjuensis''A member of Silphidae''Notocupes''''N. premeris''A member of Archostemata''Asiana''''A. pax''''Brochocoleus''''B. sacheonensis''A member of Ommatidae ''B.'' cf. ''punctatus'' ''Omma''''O.'' sp.''Zygadenia''''Z. cornigera''==== Diptera ====+Flies of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Buccinatormyia''''B. gangnami''A member of the family Zhangsolvidae. Named after Gangnam Style, the famous K-Pop hit song==== Dermaptera ====+Earwigs of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''cf. Pygidicranoideaindeterminate==== Neuroptera ====Lacewings of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Tachinymphes''''T. koraiensis''A member of the family Mesochrysopidae.==== Termites ====Termites of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Sclerotermes''''S. samsiki''Known only from an isolated wing, uncertain placement=== Crustaceans ======= Isopoda ====+Isopods of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Archaeoniscus''''A. coreaensis''A freshwater occurrence of the genus ''Archaeoniscus''==== Ostracoda ====+Ostracods of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Scabriculocypris''''S. cf. yanbianensis''Jeongcheon''Cypridea''* ''C. jinjuria''* ''C. khandae''* ''C. samesi''''C. jinjuria'' in Gwanghyeon''Mongolocypris''''M. kohi''''Lycopterocypris''''L. cf. celsa''Jeongcheon''Candona''''C. sp.''''Djungarica''''D. sp. ''Jeongcheon==== Spinicaudata ====+Clam shrimps of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Yanjiestheria''* ''Y. kyongsangensis''* ''Y. chekiangensis''* ''Y. cf. wannanensis''* ''Y. jinjuensis''* ''Y. sp. ''=== Vertebrates ======= Actinopterygii ====+Fishes of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Wakinoichthys''''W. aokii''An osteoglossiformthumb''Jinjuichthys''''J. cheongi''An ichthyodectiformthumbAlbuliformesindeterminate''Sinamia''''S. sp. ''An amiiform''Lepidotes''''L. sp. ''Largest fish found in this formation, reaching  in total length.LepisosteiformesindeterminateElopiformesindeterminateA small fish, reaching  in total length.==== Archosauria ====+Reptiles of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''Crocodyliformes indet.Goryeonga right mandibleTitanosauriformes indet.Sacheona toothInitially suggested to be of Asian Brachiosaurid by Lim, Martin and Baek (2001), but Barrett et al. (2002) and Choi & Lee (2017) considers it to be indeterminate titanosauriform.Pterodactyloidea indet.GoryeongteethWhile suggested to be of Boreopterid origin by Choi & Lee (2017), Yun (2021) and Yun (2024) considers them to be Anhanguerian instead on the basis of the morphological disparity from Boreopteridae and the results of two-dimensional geometric morphometric analyses.=== Mollusks ======= Bivalvia ====+Bivalves of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Plicatounio''''P. naktongensis''''Nagdongia''''N. soni''The genus ''Nagdongia'' is considered to be synonymous with ''Nakamuranaia'' by some.''Trigonioides''''T. jaehoi''==== Gastropoda ====+Gastropods of the Jinju Formation'''Genus''''''Species''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Brontiopsis''''B. kobayashi''dominant gastropod of the formation''Thiara''''T. sp''''Viviparus''=== Ichnofossils ===+Ichnofossils of the Jinju Formation'''Ichnogenus''''''Ichnospecies''''''Region''''''Member''''''Material''''''Notes''''''Image'''''Grallator''Theropod track; similar to the ichnospecies ''G. yangi''''Corpulentapus''Theropod track''Asianopodus''Theropod track''Dromaeosauriformipes''''D. rarus''Didactyl tracks made by either juvenile dromaeosaur or very small species of trackmaker, represents the smallest non-avian dinosaur tracks known. ''Dromaeosauripus''''D. jinjuensis''NamhaeDidactyl tracks made by a  tall dromaeosaur.''Ignotornis''''I. seoungjoseoi''Bird Track''Jindongornipes''''J''. isp.Bird Track''Koreasaltipes''''K. jinjuensis''JinjuTraces left by a hopping mammal''Neosauroides''''N. innovatus''The largest reported lizard trackway in South Korea.cf. ''Chelichnus''SacheonTurtle trackway. ''Ranipes''indeterminateOldest known frog trackway. Made by a species that hopped in short distances. ''Crocodylopodus''First report of this ichogenus from Asia.''Batrachopus''''B. grandis''Track made by a  long bipedal crocodylomorph; the pterosaur trackway ichnospecies ''Haenamichnus gainensis'' from the Haman Formation is now assigned to this species as ''B.'' cf. ''grandis''. Paleontologist James I. Kirkland expresses doubts on the ichnogenus assignment.''Minisauripus''''M''. isp.One of the smallest known theropod tracks. Currently the oldest record of this ichnogenus from South Korea.''Pteraichnus''*''P. gracilis''*"''P. seopoensis''"Pterosaur trackway. ''P. seopoensis'' is currently a naked name, since it was only described in a master's thesis.''Lockeia''''L. gigantus''Resting bivalve trace fossils''Diplichnites''''D''. isp.Arthropod tracks''Coclichnus''''C.'' isp.Trace by Annelida tracemakers''Radialimbricatus''''R. bitoensis''Potential tracemakers include arthropods, cnidarians or annelids''Protovirgularia''''P. dichotoma''First nonmarine occurrence of this ichnotaxon; possibly made by larvae of dragonfly''Fictovichnus''indeterminateProbable insect cocoon or pupation chamber; the earliest record of an insect pupation structure probably associated with a burrow
See also * :ko:경상 분지 (Gyeongsang Basin)* * List of dinosaur- bearing rock formations** List of stratigraphic units with indeterminate dinosaur fossils
References === Bibliography ===* *