• Source: Madygen Formation

The Madygen Formation (Russian: Madygen Svita) is a Middle–Late Triassic (Ladinian–Carnian) geologic formation and lagerstätte in the Batken and Osh Regions of western Kyrgyzstan, with minor outcrops in neighboring Tajikistan and Uzbekistan. The conglomerates, sandstones and mudstones of the 560 m (1,840 ft) thick formation were deposited in terrestrial lacustrine, alluvial, fluvial and deltaic environments.
The formation, extending across the Fergana Valley and Fergana Range, is unique for Central Asia, as it represents one of the few known continental deposits and the Madygen Formation is renowned for the preservation of more than 20,000 fossil insects, making it one of the richest Triassic lagerstätten in the world. Other vertebrate fossils as fish, amphibians, reptiles and synapsids have been recovered from the formation too, as well as minor fossil flora.
The lake sediments of the Lagerstätte provided fossil cartilaginous fishes and their egg capsules and unusual Triassic reptiles like Sharovipteryx and Longisquama. The wide diversity of insect fossils was first discovered in the 1960s and first described by Russian paleontologist Aleksandr Sharov, with a notable example being Gigatitan.




Description



The Madygen Formation is a 560 metres (1,840 ft) thick succession of predominantly siliciclastic rocks accumulated in a tectonically induced basin, covering parts of the Fergana Range and Fergana Valley of Kyrgyzstan with minor outcrops in Tajikistan and Uzbekistan. The Middle-Late Triassic layers rest on top of Paleozoic basement with local Permo-Triassic molasse sediments. They are likewise overlain by latest-Triassic to Early Jurassic sediments, some of which host their own arthropod faunas.
The formation consists of a wide and multicolored variety of siliciclastic rocks: mudstones, sandstones, conglomerates, fanglomerates, and rare coal layers. This diversity of sediment types reflects the a complex set of depositional environments through time and space, including alluvial fans, sandflats, swamps, back-swamp areas, and littoral to profundal lake zones. The fluvio-lacustrine deposits of the Madygen Formation belong to one of only a few occurrences of continental Triassic beds in Central Asia.
Isotope analyses of fish teeth confirm that the lakes and rivers represented by the formation were entirely freshwater and deep inland, about 600 km from the nearest coast. Though fossils can be found throughout the entire formation, the most extensive fossil deposits occur in the northern area, known as Dzaylyaucho (also spelled Dzhayloucho or Dzhailoucho), which is dominated by brown and grey claystones and mudstones. The abundance of burrows and absence of darker sediments in this area indicate that it was a well-oxygenated lacustrine environment, such as a large oxbow lake.
The environment represented by the Madygen Formation was positioned on the Cimmerian microcontinent, a slab of crust that collided with Laurasia during the Cimmerian orogeny in later Mesozoic times. This orogeny led to the disappearance of the Paleo-Tethys Ocean. The Madygen Formation was emplaced at warm temperate latitudes (34° to 40° north) in a rift basin surrounded by old, eroded mountains, the ancestral Tien Shan Mountains. The climate was likely humid and moist year-round, as drying features such as mudcracks and evaporite deposits are absent.




= Petroleum geology

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The formation grades from bottom to top from alluvial to fluvial into a thick succession of lacustrine mudstones, followed by an alluvial package, on top of which lacustrine, fluvial, deltaic and alluvial layers were deposited.
The hydrocarbon potential of samples of the Madygen Formation ranges from poor to excellent. The sediments containing more than 0.5% Total Organic Carbon (TOC) may be regarded as sources of gaseous hydrocarbons rather than of oil. The Hydrogen Index (HI) of outcrop samples reaches 100 and the maximum recorded maturity (Ro) is 0.8.




Paleontological significance


During the 1960s, Russian paleontologists recovered an unusually rich fossil content in the type strata of the Madygen Formation, including abundant macrophytes, more than 20,000 insect remains and unique small reptiles with well preserved soft tissue. Spirorbis-like polychaete worm tubes, crustaceans (ostracods, kazacharthrans, conchostracans, malacostraca), freshwater Bivalves and gastropods are known from shallow to deeper lake environments. Non-aquatic insects are among the most common fossil remains of the Madygen Formation, with half a thousand or so species having been uncovered from these sediments. This makes the Madygen Formation one of the most prolific insect fossil sites In the world. These include representatives of both extinct and extant orders, including the Ephemeroptera, Odonata, Notoptera, Blattodea, Titanoptera, Ensifera, Caelifera, Rhynchota, Auchenorrhyncha, Stenorrhyncha, Coleoptera, Hymenoptera, Trichoptera and Diptera. Traces of insect larvae are preserved in near-shore lake deposits.
Fish remains mostly represent endemic genera assigned to the actinopterygian families Evenkiidae (Oshia), Palaeoniscidae (Ferganiscus, Sixtelia) and Megaperleidus and Alvinia. The actinopterygian Saurichthys and the dipnoan Asiatoceratodus are cosmopolitan taxa also recorded in the Madygen Formation. Two distinctive elasmobranch egg capsule types, i.e. Palaeoxyris, indicating a small Lissodus- or Lonchidion-like hybodont shark and an indeterminate capsule type, imply the presence of two different elasmobranch species which used the freshwater environments of the Madygen Formation as spawning grounds. Tetrapods (and stem-tetrapods) are known from the mostly larval urodelan (Triassurus), a small procynosuchid cynodont (Madysaurus), a chroniosuchid reptiliomorph (Madygenerpeton), an early drepanosaurid reptile (Kyrgyzsaurus), a gliding archosauromorph (Sharovipteryx) and the enigmatic diapsid Longisquama.




Paleobiota






= Amphibians

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= Reptiles

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Reptiles are the most abundant of the tetrapod paleofauna at Madygen, with three described genera.




= Synapsids

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= Cartilaginous fishes

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Possible xenacanth denticles, egg cases, as well as hybodont fossils have also been reported from the formation. The high amount of juvenile individuals found suggest the freshwater systems at the Madygen Formation served as a spawning grounds and nursery's for these prehistoric elasmobranchs.




= Bony fishes

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The following fish fossils were found in the formation:




= Insects

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The Madygen Formation is renowned for its insect fauna, with an estimated 25,000 specimens, 500 species, 100 families, and 20 orders found in the formation. Under some estimates, it has the most diverse insect assemblage of the entire Permian-Triassic interval. From EDNA (The Fossil Insect Database), Shcherbakov (2008), and the Paleobiology Database, unless cited otherwise:



Odonata (damselflies, dragonflies and kin)

The Odonata and other Odonatoptera of the Madyen Formation are rare (about 100 specimens), with moderate diversity. They were described most extensively by Pritykina (1981).

†Paurophlebiidae (8 species): Cladophlebia (C. brevis, C. parvula), Neritophlebia (N. elegans, N. longa, N. vicina), Nonymophlebia (N. venosa), Paurophlebia (P. angusta, P. lepida)
†Triadophlebiidae (6 species): Triadophlebia (T. distincta, T. honesta, T. madygenica, T. magna, T. minuta, T. modica)
†Zygophlebiidae (4 species): Cyrtophlebia (C. sinuosa), Mixophlebia (M. mixta), Zygophlebia (Z. ramosa), Zygophlebiella (Z. curta)
†Kennedyidae (4 species): Kennedya (K. carpenteri, K. ferganensis, K. gracilis, K. madygensis)
†Voltzialestidae (3 species): Terskeja (T. paula, T. pumilio, T. tenuis)
†Batkeniidae (2 species): Batkenia (B. pusilla), Paratriassoneura (P. primitiva)
†Mitophlebiidae (1 species): Mitophlebia (M. enormis)
†Protomyrmeleontidae (1 species): Ferganagrion (F. kirghiziensis)
†Triadotypidae (1 species): Reisia (R. sogdiana)
†Triassolestidae (1 species): Triassolestodes (T. asiaticus)
†Xamenophlebiidae (1 species): Xamenophlebia (X. ornata)



Blattodea (roaches)

The Blattodea of the Madygen Formation are extremely abundant (a quarter of all insect fossils collected), and some preserve details of the entire body. Roaches in the families †Caloblattinidae and †Spiloblattinidae are particularly common and diverse, though most species remain undescribed. Some species were given a preliminary description by Vishniakova (1998).

†Caloblattinidae: Sogdoblatta (S. maxima, S. nana, S. porrecta), Thuringoblatta (T. sogdianensis)
†Subioblattidae: Subioblatta (S. madygenica)
Undescribed species of †Blattulidae, †Phyloblattidae, †Poroblattinidae, †Spiloblattinidae, and potentially †Archimylacridae.



†Titanoptera


The †Titanoptera of the Madygen Formation are uncommon (about 200 specimens), with moderate diversity, though still higher than any other geological formation. They were described most extensively by Sharov (1968) and Gorochov (2003). One titanopteran of special note is Gigatitan vulgaris, one of the few insects from the formation known from more than wings. This species was a superficially mantis-like diurnal predator with a wingspan of approximately 40 centimetres (16 in). Like other large titanopterans, it was probably a poor flier which primarily used its wings to produce sounds or flashes of light for courtship of defensive purposes.

†Paratitanidae (11 species): Microtitan (M. zherichini), Paratitan (P. bispeculum, P. intermedius, P. latispeculum, P. libelluloides, P. longispeculum, P. modestus, P. ovalis, P. reductus, P. reliquia, P. venosus)
†Mesotitanidae / †Gigatitanidae (11 species): Gigatitan (G. ovatus, G. similis, G. vulgaris), Mesotitanodes (M. tillyardi), Nanotitan (N. extentus, N. magnificus), Ootitan (O. curtis), Prototitan (P. primitivus, P. sharovi, P. similis), Ultratitan (U. superior)
Note: Béthoux (2007) considers †Titanoptera to simply be a suborder of orthopterans, rather than its own order. Under this system, the diversity of Madygen titanopterans is also reduced to seven species spread out across two genera (Mesotitan and Gigatitan).



Orthoptera (grasshoppers and kin)

The Orthoptera of the Madygen Formation are very common (about 1400 specimens) and very diverse (over 100 species). Most species belong to the suborder Ensifera (kin of crickets, katydids, and grigs), with only a few Caelifera (kin of grasshoppers). None of the families survive to the present, and most are endemic to the Triassic. Madygen orthopterans were described most extensively by Sharov (1968) and Gorochov (1986, 1987, 1994, 2005).

†Haglidae (44 species): Ahagla (A. mira), Archihagla (A. tenuis, A. zeuneri), Cantohagla (C. gracilis), Dinohagla (D. corrugata), Dolichohagla (D. longa), Dulchihagla (D. beybienkoi, D. mistshenkoi), Eumaraga (E. madygenica), Euvoliopus (E. giganteus), Haglomorpha (H. martynovi), Hagloptera (H. intermedia), Lyrohagla (L. decipiens, L. pravdini, L. uvarovi), Macrovoliopus (M. declivis), Maragella (M. reducta), Melovoliopus (M. fasciatus), Microhagla (M. minuta), Modihagla (M. ovalis), Paravoliopus (P. dorsalis), Phonovoliopus (P. musicus), Platyvoliopus (P. maximus), Proisfaroptera (P. martynovi), Protshorkuphlebia (P. kirgizica, P. similis, P. triassica), Sharovohagla (S. plana), Sonohagla (S. chopardi, S. curta, S. saussurei), Stenovoliopus (S. elongatus), Tinnihagla (T. handlirschi, T. zeuneri), Triassaga (T. angusta, T. tshorkuphlebioides), Turkestania (T. deviata), Vocohagla (V. clara, V. tarbinskyi), Voliopellus (V. latus), Voliopus (V. ancestralis), Zamaraga (Z. recticulata), Zavoliopus (Z. densus), Zeunerophlebia (Z. gigas)
†Proparagryllacrididae (16 species): Batkenella (B. megaptera), Brevibatkenella (B. abscisa), Dolichobatkenella (D. perlonga), Eubatkenella (E. devexia), Gryllacrimima (G. elongata, G. madygenioides, G. perfecta, G. simplicis), Kashgarlimahmutia (K. reducta), Madygenia (M. extremalis, M. longissima, M. orientalis, M. ovalis), Oedischimima (O. deficientis), Parafergania (P. sharovi), Platymadygenia (P. grandis)
†Xenopteridae (15 species): Axenopterum (A. venosum), Ferganopterodes (F. reductus), Ferganopterus (F. clarus, F. longus), Ferganotriassia (F. lata), Proxenopterum (P. primitivum), Pseudoferganopsis (P. zini), Pteroferganella (P. crassa, P. minuta, P. sharovi), Pteroferganodes (P. decipiens, P. rieki), Triassoferganella (T. angusta), Triassomanteodes (T. madygenicus), Xenoferganella (X. pini)
†Locustavidae (9 species): Brevilocustavus (B. distinctus, B. microscopicus), Ferganopsis (F. lanceolatus), Locustavus (L. deformatus, L. intermedius, L. madygensis, L. minutus, L. problematicus), Miolocustavus (M. reductus)
†Bintoniellidae (8 species): Oshiella (O. crassa, O. oblonga), Oshiellana (O. primaria), Paroshiella (P. alia), Probintoniella (P. triassica), Proshiella (P. ramivenosa), Provitimia (P. pectinata), Stenoshiella (S. angusta)
†Dzhajloutshellidae (5 species): Adzhajloutshella (A. planis, A. talis), Dzhajloutshella (D. arcanum, D. flexuosa), Triassoxya (T. novozhilovi)
†Tuphellidae (4 species): Neotuphella (N. minor), Tuphella (T. rasnitsyni, T. rohdendorfi, T. sharovi)
†Gryllavidae (3 species): Gryllavus (G. madygenicus), Paragryllavus (P. curvatus), Zaragryllavus (Z. elongatus)
†Mesoedischiidae (3 species): Mesoedischia (M. kirgizia, M. madygenica, M. obliqua)
†Permelcanidae (2 species): Meselcana (M. madygenica, M. permelcanoides)
†Hagloedischiidae (1 species): Hagloedischia (H. primitiva)



Phasmatodea (stick insects and kin)

The Phasmatodea of the Madygen Formation are somewhat common (about 350 specimens) and somewhat low in diversity. All of the families were endemic to the Triassic. They were described most extensively by Sharov (1968) and Gorochov (1994).

†Prochresmodidae (8 species): Prochresmoda (P. longipoda, P. media, P. minuta, P. parva), Triassophasma (T. brevipoda, T. intermedium, T. minutissimum, T. pusillum)
†Aeroplanidae (2 species): Sharovoplana (S. affinis, S. parallelica)
†Xiphopteridae? (2 species): Xiphopterum (X. curvatum, X. sharovi)



Grylloblattodea (ice-crawlers and kin) and other basal polyneopterans

The Grylloblattodea and other basal polyneopterans of the Madygen Formation (sometimes described as Eoblattida or Protorthoptera, among other names) are very common (about 1500 specimens) and diverse (over 50 species). They were described most extensively by Storozhenko (1998).

†Megakhosaridae (11 species): Madygenocephalus (M. micropteron), Megablattogryllus (M. austerus, M. magister, M. pinguis), Megakhosarodes (M. obtusus, M. paulovenosus), Mesoblattogryllus (M. abruptus, M. intermedius), Metakhosara (M. sharovi), Protoblattogryllus (P. asiaticus, P. variabilis)
†Mesorthopteridae (11 species): Belmophenopterum (B. rasnitsyni), Austroidelia (A. asiatica), Locustoblattina (L. marginata, L. segmentata), Mesoidelia (M. faceta, M. rasnitsyni, M. semota), Parastenaropodites (P. fluxa, P. longiuscula, P. nervosa), Sharovites (S. alexanderi)
†Blattogryllidae (9 species): Anoblattogryllus (A. fundatus), Baharellinus (B. dimidiatus, B. pectinatus), Baharellus (B. madygensis), Costatoviblatta (C. aenigmatosa, C. conjuncta, C. longipennis, C. similis), Dorniella (D. primitiva)
†Gorochoviidae (8 species): Gorochovia (G. anomala, G. bifurca, G. fecunda, G. individua, G. minuta), Gorochoviella (G. conjuncta), Pseudoliomopterites (P. lucidus, P. obscurus)
†Ideliidae (7 species): Anaidelia (A. extrema), Ideliopsina (I. nana, I. ornata, I. ruginosa, I. stupenda), Madygenidelia (M. conjuncta), Pseudoshurabia (P. pallidula)
†Geinitziidae (5 species): Geinitziella (G. rasnitsyni), Shurabia (S. anomala, S. ferganensis, S. minutissima, S. tanga)
†Madygenophlebiidae (4 species): Madygenophlebia (M. bella, M. nana, M. primitiva), Micromadygenophlebia (M. obscura)
†Sylvabestiidae (2 species): Aiban (A. kichineis), Sharovala (S. triassica)
†Necrophasmatidae (1 species): Ferganamadygenia (F. plicata)
†Daldubidae (1 species): Batkentak (B. intactus)
†Sylvaphlebiidae (1 species): Batkenopterum (B. kirgizicum)



†Miomoptera

The †Miomoptera of the Madygen Formation are somewhat common (about 500 specimens), most or all of which belong to a single valid species.

†Permosialidae (1 species): Permosialis (P. triassica)



Plecoptera (stoneflies)

The Plecoptera of the Madygen Formation are rare (about 80 specimens) and somewhat low in diversity. They were described most extensively by Sinitchenkova (1987).

†Perlariopseidae (14 species): Cristonemoura (C. binerva, C. porrecta), Dicronemoura (D. acaulis, D. declinata, D. dira), Fritaniopsis (F. brevicaulis, F. dependens, F. remota), Ramonemoura (R. constricta), Triassonemoura (T. ficteramosa), Tritaniella (T. mera, T. pectinata, T. perlonga, T. synneura)
†Siberioperlidae (1 species): Siberioperla (S. ovalis)



Embioptera (webspinners)

The Embioptera of the Madygen Formation are rare and very low in diversity. Some Madygen mesorthopterids show similarities to alexarasniids, which may suggest that †Mesorthopteridae is ancestral to the embiopteran lineage.

†Alexarasniidae: Nestorembesia (N. novojilovi, N. shcherbakovi)
†Rasnalexiidae: Rasnalexia (R. rasnitsyni)



Hemiptera (true bugs)

The Hemiptera of the Madygen Formation are extremely abundant (a quarter of all insect fossils collected) and very diverse, though most remain undescribed. By far the most common are small cicadomorphs (kin of treehoppers, leafhoppers, and cicadas), though large butterfly-like cicadas also occur. Fulguroidea (planthoppers) and Stenorrhyncha (aphids, whiteflies, jumping plant lice) are present but uncommon. The only heteropteran in the formation is an extremely rare basal Nepomorpha similar to Ochteroidea (toad bugs and velvety shore bugs).

†Maguvopseidae: Asiocula (A. lima), Cuanoma (C. protracta), Falcarta (F. bella), Fasolinka (F. beckermigdisovae), Krendelia (K. ansata), Maguviopsis (M. kotchnevi), Nevicia (N. imitans), Nonescyta (N. mala), Phyllotexta (P. latens), Sacvoyagea (S. ventrosa), Sitechka (S. perforata)
†Palaeontinidae: Papiliontina (P. dracomima, P. machaon, P. spectans)
†Mesojabloniidae: Fulgobole (F. evansi), Mesojablonia (M. kukalovae), Scytachile (S. emeljanovi)
†Dunstaniidae: Dunstaniodes (D. elongatus), Siksteliana (S. popovi)
†Curvicubitidae: Beaconiella (B. cincta, B. pulchra)
†Creaphididae: Creaphis (C. theodora)
†Ipsviciidae: Strivicia (S. davidi)
†Naibiidae: Coccavus (C. supercubitus)
†Paraknightiidae: Triknightia (T. mira)
†Progonocimicidae: Pelorisca (P. connectens)
†Saaloscytinidae: Tingiopsis (T. reticulata)
†Serpentivenidae: Serpentivena (S.tigrina)
Undescribed species of †Chiliocyclidae, †Dysmorphoptilidae, †Hylicellidae, †Mesogereonidae, †Pincombeidae, †Protopsyllidiidae, †Scytinopteridae, †Stenoviciidae, †Surijocixiidae, and possibly Ochteroidea.



Neuroptera (lacewings and kin)

The Neuroptera of the Madygen Formation are uncommon (around 200 specimens) but diverse in form. Only a few species have been formally described.

†Archeosmylidae: Madygoneura (M. elongata), Osmylotriasia (O. superba), Triasella (T. ovata)
Berothidae (beaded lacewings): Ferganoberotha (F. miniutissima)
†Permithonidae: Relictovia (R. pristina)
Undescribed species of †Osmylopsychopidae, Osmylidae (lance lacewings), and "Polystoechotidae" (giant lacewings).



Coleoptera (beetles)

The Coleoptera of the Madygen Formation are extremely abundant (a quarter of all insect fossils collected) and diverse (over 70 named species and many more undescribed). By far the most abundant beetles are archostematans, particularly †Schizophoridae and cupedid-grade beetles (†Triadocupedidae, Ommatidae). They were described most extensively by Ponomarkenko (1966, 1969, 1977).

†Schizophoridae (17 species): Catabrycus (C. hoplites), Hadeocoleus (H. catachtonius, H. gigas, H. pelopius), Lethocoleus (L. sternalis), Pesus (P. prognathus), Praesagus (P. capitatus), Salebroferus (S. asper, S. confragosus), Schizophorinus (S. punctatus), Schizophoroides (S. glaber, S. rugosus, S. tuberculatus), Thnesidius (T. ovatus, T. xyphophorus), Triassocoleus (T. sulcatus, T. tortulosus)
†Triadocupedidae / †Triadocupedinae (16 species): Asimma (A. rara), Cupesia (C. monilicornia, C. sepulta, C. serricornia), Kirghizocupes (K. cellulosus), Platycupes (P. dolichocerus, P. major, P. pusillus, P. reticulatus, P. sogdianus), Procupes (P. mandibularis), Pterocupes (P. antennatus, P. leptocerus), Triadocupes (T. ellipticus, T. ferghanensis, T. latus)
Ommatidae / Ommatinae (reticulated beetles, 12 species): Lithocupes (L. gigas, L. incertus, L. punctatus), Notocupes? (N. laticella, N. rostratus, N. tenuis), Notocupoides? (N. capitatus, N. fasciatus, N. triassicus), Rhabdocupes? (R. baculatus, R. longus, R. minor)
†Ademosynidae (7 species): Ademosyne (A. bacca, A. elliptica, A. kirghizica), Cephalosyne (C. capitata), Dolichosyne (D. confragosa, D. rostrata, D. sulcata)
†Triaplidae (7 species): Avocatinus (A. elongatus), Catinoides (C. rotundatus), Macrocatinius (M. brachycephalus), Triaplus (T. laticoxa, T. macroplatus), Triassocatinius (T. brachynotus, T. glabratus)
†Obrieniidae (5 species): Guillermia (G. lecticula), Madygenorhynchus (M. multifidus), Obrienia (O. illaetabilis, O. ingurgata, O. kuscheli)
†Peltosynidae (4 species): Gnathopeltos (G. dixis), Ofthalmopeltos (O. synkritos), Peltosyne (P. triassica, P. varyvrosa)
†Asiocoleidae / †Tricoleidae (3 species): Sogdelytron (S. latum), Tricoleodus (T. acutus, T. longus)
Cupedidae sensu stricto / Cupedinae (reticulated beetles, 2 species): Mesocupoides (M. indistinctus, M. proporeius)
Trachypachidae (false ground beetles, 1 species): Sogdodromus (S. altus)



Hymenoptera (wasps and kin)

The Hymenoptera of the Madygen Formation are rare (about 60 specimens), but with moderate diversity. All the species belong to the sawfly family Xyelidae, which still survives to the present. They were described most extensively by Rasnitsyn (1964, 1969).

Xyelidae (xyelid sawflies, 36 species): Asioxyela (A. parvula, A. paurura, A. smilodon), Chubakka (C. madygensis), Dinoxyela (D. armata), Euryxyela (E. euryptera, E. lata), Ferganoxyela (F. destructa, F. sogdiana), Leioxyela (L. antiqua, L. grandis, L. kirgizica, L. mitis, L. mollis), Lithoxyela (L. fenestralis), Madygella (M. analoga, M. aristovi, M. bashkuevi, M. kurochkini, M. levivenosa), Madygenius (M. extraradius, M. primitivus), Oryctoxyela (O. anomala, O. triassica), Microxyela (M. minuta), Samarkandykia (S. ryzhkovae, S. shmakovi), Triassoxyela (T. foviolata, T. grandipennis, T. orycta, T. sharovi), Xiphoxyela (X. procrusta, X. striata), Xyelinus (X. angustiradius, X. major, X. scherbachov)



Mecoptera (scorpionflies)

The Mecoptera of the Madygen Formation are very common (about 1600 specimens) and fairly diverse (over 40 species). They were described most extensively by Ponomarenko & Rasnitsyn (1974), and Novokshonov (1997, 2001).

†Permochoristidae (15 species): Agetopanorpa (A. consueta, A. deceptoria, A. triassica), Liassochorista (L. molesta, L. utilis), Mecolusor (M. confusicus), Mesageta (M. gigantea, M. ignava, M. insana, M. pertrita, M. rieki), Mesochorista (M. injuriosa), Prochoristella (P. ignara, P. longa, P. vicina)
†Parachoristidae (13 species): Choristopanorpa (C. opinata, C. ridibunda, C. temperata), Kirgizichorista (K. larvata), Panorpaenigma (P. aemulum), Parachorista (P. arguta, P. asiatica, P. comica, P. immota, P. multivena, P. religiosa, P. sana), Triassochorista (T. kirgizica)
†Thaumatomeropidae (6 species): Blattomerope (B. polyneura), Pronotiothauma (P. neuropteroides), Thaumatomerope (T. madygenica, T. minuta, T. oligoneura, T. sogdiana)
†Mesopsychidae (5 species): Mesopsyche (M. gentica, M. justa, M. ordinata, M. shcherbakovi, M. tortiva)
incertae sedis (2 species): †Mecaenigma (M. suspectum, M. viduum)
†Pseudopolycentropodidae (1 species): Pseudopolycentropus (P. madygenicus)



Trichoptera (caddisflies)

The Trichoptera of the Madygen Formation are rare (fewer than 60 specimens) and low in diversity.

†Cladochoristidae: Cladochorista (C. curta), Cladochoristella (C. sola)
†Prorhyacophilidae: Prorhyacophila (P. batkenica, P. furcata, P. rara,)
†Necrotauliidae: Paranecrotaulius (P. proximus)
Philopotamidae? Prophilopotamus (P. asiaticus) (dubious)



Diptera (flies)

The Diptera of the Madygen Formation are rare and somewhat low in diversity. They were described most extensively by Shcherbakov et al. (1995). Some purported Madygen dipterans wings may belong to four-winged insects instead.

†Psychotipidae (2 species): Psychotipa (P. depicta, P. predicta)
†Protorhyphidae (2 species): Vymrhyphus (V. triassicus, V. tuomikoskii)
†Gnomuscidae? (2 species): Gnomusca (G. molecula, G. renyxa)
Chaoboridae (phantom midges, 1 species): Triassomyia (T. shcherbakovi)
†Hennigmatidae? (1 species): Anemeca (A. liya)
†Kuperwoodidae (1 species): Kuperwoodia (K. benefica)
Limoniidae (limoniid crane flies, 1 species): Mabelysia (M. charlesi)
†Nadipteridae (1 species): Nadiptera (N. pulchella)
†Vladipteridae (1 species): Dilemmala (D. specula)



Other insects

Psocoptera (book lice) are represented by a single undescribed species from the family †Psocidiidae. Dermaptera (earwigs) are also very rare and undescribed, represented by the family †Protodiplateidae. The extinct order †Glosselytrodea is only slightly more diverse, with rare fossils from the families †Jurinidae and †Polycytellidae. The only fossil Ephemeroptera (mayfly) reported from the formation is a Mesobaetis-like fragment, and its referral to a mayfly has been doubted.




= Other invertebrates

=
Apart from insects, the most common invertebrates found in the Madygen Formation are Almatium gusevi and Jeanrogerium sornayi, tadpole shrimp-like aquatic crustaceans in the order Kazacharthra. Undescribed ostracod and decapod fossils have also been found, though conchostracans are practically absent. The Madygen Formation is one of the only Triassic sites to preserve statoblasts of freshwater bryozoans (Phylactolaemata). Freshwater bivalves, gastropods, microconchid shells, and worm burrows are also found in the lakebed sediments.




= Flora

=
The plant fossils of the Madygen Formation were reviewed in detail by Dobruskina (1995). Among the oldest known root nodules have been found in the Madygen Formation, though the exact nature of the plant-microbe interaction responsible remains unknown.



Non-vascular plants




Ferns, horsetails, and lycopods

Ferns are rare and poorly-preserved, though certain horsetails (Neocalamites) and lycopods (Ferganadendron, Mesenteriophyllum, Isoetites) are more common.



Pteridosperms ("seed ferns")

Pteridosperms are abundant and diverse, making up more than half of all the plant fossils recovered from the formation.



Other gymnosperms

Though subordinate to pteridosperms in terms of abundance, other gymnosperms are still quite diverse, and some of them (Glossophyllum, Podozamites, Taeniopteris) are far from uncommon.




= Insect fauna correlations

=
Progonocimicidae found in the formation are also recorded in the Carnian Los Rastros Formation of Argentina, the Norian Blackstone and Mount Crosby Formations of Australia, and the Norian to Rhaetian Tologoi Formation of Kazakhstan. Permochoristidae are also known from the Carnian Potrerillos and Cacheuta Formations of Argentina, Huangshanjie Formation of China, the Norian Blackstone and Mount Crosby Formations of Australia; the Norian to Rhaetian Tologoi Formation of Kazakhstan, the Sinemurian Dzhil Formation of Kyrgyzstan and the Toarcian Posidonia Shale of Germany.
Orthophlebia had a relatively broad distribution in the Late Triassic as it is also found in the Sinemurian Badaowan Formation of China and Dzhil Formation of Kyrgyzstan, the Pliensbachian Makarova Formation of Russia and Sulyukta Formation of Tajikistan; the Toarcian Whitby Mudstone Formation of England, Posidonia Shale of Germany, and Cheremkhovo Formation of Russia, and the Early Jurassic Kushmurun Formation of Kazakhstan.
Haglidae were also recorded in the Koldzat and Tologoi Formations of Kazakhstan, in the Carnian Cacheutá Formation of Argentina, the Carnian to Norian Molteno Formation of South Africa and Lesotho, and the Norian Mount Crosby Formation of Australia.




See also






References






= Further reading

=
Gorochov, A.V (2005), "Review of Triassic Orthoptera with Descriptions of New and Little Known Taxa: Part 2", Paleontological Journal, 39 (3): 272–279
Novokshonov, V.G (1997), "New Triassic Scorpionflies (Insecta, Mecoptera)", Paleontological Journal, 31: 628–635
Shcherbakov, D.E.; Lukashevich, E.D.; Blagoderov, V.A. (1995), "Triassic Diptera and initial radiation of the order", International Journal of Dipterological Research, 6: 75–115
Storozhenko, S.Y (1993), "Reviziya semeystva Megakhosaridae (Grylloblattida) In A. G. Ponomarenko (ed.)", Mezozoyskie Nasekomye I Ostrakody Azii: 100–112
Arnoldi, L.V.; Zherikhin, V.V.; Nikritin, L.M.; Ponomarenko, A.G. (1977), "Mezozoiskie zhestkokryiye", Akademiya Nauk SSSR, Trudy Paleontologicheskogo Instituta, 161: 1–204
Ponomarenko, A.G (1969), "Istoricheskoe Razvitie Zhestkokrylykh-Arkhostemat [Historical Development of the Archostomate Beetles]", Trudy Akademiya Nauk SSSR, 125: 1–240
Sharov, A.G (1968), "Filogeniya ortopteroidnykh nasekomykh", Trudy Paleontologicheskogo Instituta Akademii Nauk SSSR, 118: 1–216
Becker-Migdisova, E.E (1953), "Dva predstavitelya poluzhestkokrylykh nasekomykh iz urochishcha Madygen", Doklady Akademii Nauk SSSR, 90: 461–464

Kata Kunci Pencarian:

• Madygen Formation
• Carnian
• Lagerstätte
• Cupedidae
• Madysaurus
• Triassurus
• Gigatitan
• Sharovipteryx
• Longisquama
• Ademosynidae