The Balabansai Formation (sometimes transcribed Balabansay,[1] also known as Balabansai Svita) is a geological formation in Kazakhstan, Kyrgyzstan and Uzbekistan whose strata date back to the Bathonian and Callovian stages of the Middle Jurassic. Dinosaur remains are among the fossils that have been recovered from the formation.[2] The lithology primarily consists of variegated sandstones, siltstones, claystones, and rare gravels and marls.[3] Many taxa have been found in the formation, including amphibians[4] and mammals[5]
Balabansai Formation | |
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Stratigraphic range: Bathonian-Callovian ~ | |
Type | Geological formation |
Underlies | Hodzhiabad Formation[1] Cretaceous red beds |
Overlies | Igrysai Svita[1] |
Thickness | Up to 250 m (820 ft) |
Lithology | |
Primary | Sandstone, siltstone, claystone |
Other | Gravel, marl |
Location | |
Coordinates | 41°18′N 72°06′E / 41.3°N 72.1°E |
Approximate paleocoordinates | 40°54′N 76°12′E / 40.9°N 76.2°E |
Region | Ongtustik Qazaqstan oblysy, Jalal-Abad Region |
Country | Kazakhstan Kyrgyzstan Uzbekistan |
Balabansai Formation (Kyrgyzstan) |
Indeterminate Avialae remains located in Ongtustik Qazaqstan Oblysy, Kazakhstan.[2]
Fish of the Balabansai Formation | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Ferganamia | F. verzilini | A bowfin | ||
Ferganoceratodus | F. jurassicus | A lungfish | ||
Palaeobates | P. verzilini | An elasmobranch | ||
Polyacrodus | P. balabansaiensis, P. prodigialis | A hybodont |
Amphibians of the Balabansai Formation | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Ferganobatrachus[6] | F. riabinini | Temnospondyl | ||
Kokartus | K. honorarius | Salamander |
Turtles of the Balabansai Formation | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Toxocheloides | T. narynensis | |||
Xinjiangchelys | X. tianshanensis, X. latimarginalis | Xinjiangchelydae |
Lizards of the Balabansai Formation | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Changetisaurus | C. estesi | Relative of Dorsetisaurus | ||
Lacertilia | Indeterminate |
Choristoderes of the Balabansai Formation | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Choristodera | Indeterminate | Similar to Cteniogenys |
Crocodyliformes | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Sunosuchus | Indeterminate |
Dinosaurs | |||||
---|---|---|---|---|---|
Genus | Species | Presence | Material | Notes | |
P. sharovi[2] |
Geographically located in Ongtustik Qazaqstan Oblysy, Kazakhstan.[2] | ||||
Ferganasaurus[7] | F. verzilini | Located within Kyrgyzstan | Basal Sauropod | ||
Ferganocephale[3] | F. adenticulatum | Located within Kyrgyzstan | Dubious taxon, Neornithischia indet. | ||
Neosauropoda indet.[3] | Family, genus and species indeterminate | Kyrgyzstan | A heavily worn tooth, the apex of a tooth crown, a left metatarsal I, and a right manual phalanx | ||
Tetanurae indet.[3] | Family, genus and species indeterminate | Kyrgyzstan | Dozens of teeth | ||
Stegosauria indet.[8] | Family, genus and species indeterminate | Kyrgyzstan | Four posterior dorsal vertebrae | May be as old as Adratiklit. Remains not diagnostic, given nomen nudum "Ferganastegos" by Roman Ulansky. |
Mammals | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Rhamphorhynchinae indet.[3] | Genus and species indeterminate | Kyrgyzstan |
Mammals | ||||
---|---|---|---|---|
Genus | Species | Presence | Notes | |
Ferganodon | F. cf. naryensis | A eutriconodont | ||
Paritatodon | Indeterminate | A docodont or a shuotheriid | ||
Simpsonodon | Indeterminate | A docodont, multiple species present | ||
Tashkumyrodon[9] | T. desideratus | A docodont | ||
Amphilestidae | Indeterminate | |||
Amphitheriidae | Indeterminate | |||
Docodonta | Indeterminate | |||
Paurodontidae | Indeterminate | |||
Tegotheriidae | Indeterminate | |||
Tinodontidae | Indeterminate | |||
Triconodontidae | Indeterminate |
Genus | Species | Presence | Notes |
---|---|---|---|
Proparreysia[10] | "P. thashkumyrica" | A bivalve | |
Sulcatapex[10] | "S. chatkalica" | A bivalve | |
Yeniella[10] | "Y. asiatica", "Y. sculpturata" | A bivalve |
Genus | Species | Presence | Notes |
---|---|---|---|
Podozamites[10] | P. lanceolatus |
Genus | Species | Presence | Notes |
---|---|---|---|
Cladophlebis[10] | C. whitbiensis | ||
Coniopteris[10] | C. furssenkoi, C. hymenophylloides |