Csehbánya Formation

Csehbánya Formation
Stratigraphic range: Late Santonian,
~85–84 Ma
TypeGeological formation
UnderliesJákó Marl Formation, localized unconformity with Eocene Iharkút Conglomerate present in some areas
OverliesUnconformity with Upper Triassic Main Dolomite Formation and Upper Cretaceous Nagytárkány Bauxite Formation
AreaTransdanubian Mountains
ThicknessVaries, but up to 100–150 m (330–490 ft)
Lithology
PrimarySiltstone, sandstone conglomerate
OtherClaystone
Location
Coordinates47°14′N 17°38′E / 47.24°N 17.64°E / 47.24; 17.64
Approximate paleocoordinates31°00′N 18°36′E / 31.0°N 18.6°E / 31.0; 18.6
RegionEurope
Country Hungary
Type section
Named forCsehbánya, Hungary
Csehbánya Formation is located in Hungary
Csehbánya Formation
Csehbánya Formation (Hungary)
Stratigraphy of the Iharkút locality

The Csehbánya Formation is a geological formation in the Transdanubian Mountains of Veszprém County, Hungary. The formation dates to the Late Santonian (around 85-84 million years ago) of the Late Cretaceous. It represents a floodplain environment as opposed to the swampy lacustrine environment of the simultaneous Ajka Coal Formation, though there is complete overlap in terms of fauna. It underlies the Jákó Marl Formation, and laterally transitions to the Ajka Coal Formation.

Geology

The lithology of the unit is a cyclic variation of conglomerate, sandstone, variegated siltstone, clay and marl layers with some sporadic thin coal seams. It is unconformably overlies the Late Triassic Main Dolomite Formation, which has deposits of the Upper Cretaceous Nagytárkány Bauxite Formation within deep karstic sinkholes in the formation. There is a basal conglomerate of dolomite clasts at the base of the Csehbánya formation. The main exposed portion of the formation is called the Iharkút locality, which is a disused bauxite quarry. At this location due to Paleogene uplift, it is unconformably overlain by the Lutetian Ikharkút Conglomerate. In the upper levels of the formation, there are sandstone lens beds present, which represent channel bodies. These are indicative of an anastomosing fluvial system. The exposure at this locality is between 100–150 m. Most of the fossils are found within the SZ-6 site at the locality, which is interpreted as a lag channel deposit

Invertebrate paleofauna

Amber is known from both the Ajka Coal and Csehbánya Formations, and is commonly referred to as ajkait. However most of the arthropod inclusions in these are undescribed, only being shown in photographs, With only two species of Ceratopogonids (biting midges) in the extant genus Leptoconops and the extinct genus Adelohelea being described. A list of known taxa is given below.

Invertebrates
Genus Species Location Stratigraphic position Abundance Notes Images
Adelohelea A. magyarica Biting midge
Leptoconops L. clava Biting midge, genus currently extant
Coleoptera Indeterminate
Diptera Indeterminate
Hymenoptera Indeterminate
Nematocera Indeterminate

Vertebrate paleofauna

Various fossils from the Csehbánya Formation

Fishes, amphibians, turtles, squamates, crocodilians, dinosaurs, birds and pterosaurs present in Veszprém, Hungary, near the village of Németbánya in the Iharkút locality, an open-pit bauxite mine. Other finds include Abelisauridae indet., Rhabdodontidae indet., Tetanurae indet. Coprolites and eggshells are also known from the locality.

Fish

Fish
Genus Species Location Stratigraphic position Abundance Notes Images
Atractosteus Indeterminate Iharkút locality "Jaw fragments, teeth, scales, vertebrae" Gar, genus extant
Coelodus Indeterminate Possible dentary/premaxilla, vomers, prearticulars, teeth and possible scales Pycnodontiform
Vidalamiinae Indeterminate "Two vertebrae"
Amiidae Indeterminate A left anterior ceratohyal and a vertebra
Elopiformes Indeterminate 13 vertebrae
Ellimmichthyiformes Indeterminate At least two distinct taxa represented by four and one vertebrae Clupeimorph
cf. Salmoniformes Indeterminate two vertebrae
Acanthomorpha Indeterminate Three vertebrae and 18 fin spines
Teleostei Indeterminate Teeth, vertebrae and cycloid scales
Actinopterygii Indeterminate 9 distinct teeth morphotypes and some teeth bearing elements

Amphibians

Amphibians
Genus Species Location Stratigraphic position Abundance Notes Images
Albanerpeton Indeterminate Iharkút locality Skull and jaw elements Albanerpetontid
Bakonybatrachus B. fedori Iharkút locality Pelvic elements Discoglossid frog
Hungarobatrachus H. szukacsi Iharkút locality Pelvic elements Advanced frog
Palaeobatrachidae Indeterminate Iharkút locality Postcranial remains
Pelobatidae Indeterminate Iharkút locality Postcranial remains

Squamates

Squamates
Genus Species Location Stratigraphic position Abundance Notes Images
Bicuspidon B. aff. hatzegiensis Fragmentary mandibles, maxillae Polyglyphanodontid
Chromatogenys C. tiliquoides Partial right mandible Scincomorph
Distortodon D. rhomboideus Dentaries, maxilla Polyglyphanodontid
Pannoniasaurus P. inexpectatus Partial skeleton Mosasaur, also known from Ajka Coal Formation
Pelsochamops P. infrequens Fragmentary dentary, dentary fragments Chamopsiid
Scincomorpha Indeterminate Fragmentary dentaries At least 3 distinct taxa, 4 mentioned in paper, but unsure if this counts Chromatogenys

Crocodyliformes

Crocodyliformes of the Csehbánya Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Iharkutosuchus I. makadii "Complete and partial skulls, mandibles, various cranial elements, teeth" Hylaeochampsid
Doratodon D. carcharidens "Teeth, Jaw fragment"
?Theriosuchus Indeterminate "Teeth, cranial elements"
?Allodaposuchus Indeterminate "Teeth, jaw fragments, cranial elements"

Turtles

Turtles of the Csehbánya Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Foxemys F. trabanti "Complete and partial skulls, mandibles, vertebrae, pectoral and pelvic girdle elements, limb bones, plastron and carapax fragments"
Kallokibotion Indeterminate Shell fragments
Dortokidae Indeterminate Shell fragments

Pterosaurs

Pterosaurs of the Csehbánya Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Bakonydraco B. galaczi Veszprém "Premaxilla, complete mandible, 56 mandibular symphyses" Tapejarid
Azdarchidae Indeterminate "Cervical vertebrae, pelvic girdle elements, limb bones"
Pterodactyloidea Indeterminate "3 mandibular symphyses"

Non-avian dinosaurs

Dinosaurs of the Csehbánya Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Ajkaceratops A. kozmai Fused premaxillae and rostral bones, with fragments of the maxillae, four predentaries. Referred teeth. Bagaceratopsid ceratopsian
Hungarosaurus H. tormai Veszprém Several partial skeletons Struthiosaurine nodosaur
Pneumatoraptor P. fodori Veszprém Single left scapulocoracoid Paravian
Mochlodon M. vorosi Partial skull and postcrania Rhabdodontid
Struthiosaurus Indeterminate Humerus and partial hip, and pelvic armor elements. Struthiosaurine nodosaur
Paraves Indeterminate "Teeth, caudals, limb bones"
Abelisauridae Indeterminate Femur and pedal ungual phalanx
Tetanurae Indeterminate More than 50 teeth
Sauropoda Indeterminate Single tooth

Birds

Birds of the Csehbánya Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Bauxitornis B. mindszentyae Single left metatarsus An avisaurid enantiornithine
Enantornithine Indeterminate Limb bones

See also


This page was last updated at 2023-09-18 02:16 UTC. Update now. View original page.

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