Balabansai Formation

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
Stratigraphic range: Bathonian-Callovian ~168–164 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
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	41.3°N 72.1°E / 41.3; 72.1
Approximate paleocoordinates	40.9°N 76.2°E / 40.9; 76.2
Region	Ongtustik Qazaqstan oblysy, Jalal-Abad Region
Country	Kazakhstan  Kyrgyzstan  Uzbekistan
Balabansai Formation (Kyrgyzstan)

Vertebrate paleofauna

Indeterminate Avialae remains located in Ongtustik Qazaqstan Oblysy, Kazakhstan.^[2]

Fish

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

Amphibians of the Balabansai Formation
Genus	Species	Presence	Notes
Ferganobatrachus[6]	F. riabinini		Temnospondyl
Kokartus	K. honorarius		Salamander

Turtles

Turtles of the Balabansai Formation
Genus	Species	Presence	Notes
Toxocheloides	T. narynensis
Xinjiangchelys	X. tianshanensis, X. latimarginalis		Xinjiangchelydae

Lizards

Lizards of the Balabansai Formation
Genus	Species	Presence	Notes
Changetisaurus	C. estesi		Relative of Dorsetisaurus
Lacertilia	Indeterminate

Choristoderes

Choristoderes of the Balabansai Formation
Genus	Species	Presence	Notes
Choristodera	Indeterminate		Similar to Cteniogenys

Crocodyliformes

Crocodyliformes
Genus	Species	Presence	Notes
Sunosuchus	Indeterminate

Dinosaurs

Dinosaurs
Genus	Species	Presence	Material	Notes
Praeornis[2]	P. sharovi[2]	Geographically located in Ongtustik Qazaqstan Oblysy, Kazakhstan.[2]
Alpkarakush[7]	A. kyrgyzicus	Jalal-Abad Oblast, Kyrgyzstan	A partial skeleton including skull bones, partial pectoral and pelvic girdles, dorsal and sacral vertebrae, and most of the hindlimbs	A metriacanthosaurid theropod
Ferganasaurus[8]	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.[9]	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.

Pterosaurs

Mammals
Genus	Species	Presence	Notes
Rhamphorhynchinae indet.[3]	Genus and species indeterminate	Kyrgyzstan

Mammals

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[10]	T. desideratus		A docodont
Amphilestidae	Indeterminate
Amphitheriidae	Indeterminate
Docodonta	Indeterminate
Paurodontidae	Indeterminate
Tegotheriidae	Indeterminate
Tinodontidae	Indeterminate
Triconodontidae	Indeterminate

Invertebrate paleofauna

Molluscs

Genus	Species	Presence	Notes
Proparreysia[11]	"P. thashkumyrica"		A bivalve
Sulcatapex[11]	"S. chatkalica"		A bivalve
Yeniella[11]	"Y. asiatica", "Y. sculpturata"		A bivalve

Flora

Conifers

Genus	Species	Presence	Notes
Podozamites[11]	P. lanceolatus

Ferns

Genus	Species	Presence	Notes
Cladophlebis[11]	C. whitbiensis
Coniopteris[11]	C. furssenkoi, C. hymenophylloides

See also

• List of dinosaur-bearing rock formations