Bostobe Formation

The Bostobe Formation (Kazakh: Boztóbe svıtasy) is a geological formation in Qaraghandy & Qyzylorda, Kazakhastan whose strata date back to the Late Cretaceous (Santonian to early Campanian stages, approximately 85 Ma).

Bostobe Formation
Stratigraphic range: Santonian-early Campanian ~85 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Underlies	Akzhar Formation
Overlies	Zhirkindek Formation
Thickness	About 45 m (148 ft)
Lithology
Primary	Sandstone
Other	Claystone
Location
Coordinates	45.9°N 64.7°E / 45.9; 64.7
Approximate paleocoordinates	38.7°N 58.0°E / 38.7; 58.0
Region	Qaraghandy & Qyzylorda
Country	Kazakhstan
Type section
Named for	Bostobe River
Bostobe Formation (Kazakhstan)

The sandstones and claystones of the formation were deposited in estuarine, fluvial-lacustrine and fluvial-deltaic environments.

Dinosaur remains are among the fossils that have been recovered from the formation.^[1] The formation is about 45 metres (148 ft) thick and consists primarily of clay with interbeds of sand, representing an estuarine environment.^[2]

Fossil content

Khunnuchelys lophorhothon, a trionychid turtle recovered from the formation, was initially thought to belong to a hadrosaurid dinosaur and classified as cf. Lophorhothon sp.^[3]

Mammals

• Beleutinus orlovi
• Zhalmouzia bazhanovi^[4]
• Parazhelestes sp.^[5]

Ankylosaurs

• Ankylosauridae indet.

Ornithopods

• Aralosaurus tuberiferus
• Arstanosaurus akkurganensis
• Batyrosaurus rozhdestvenskyi

Sauropods

• Opisthocoelicaudiinae Indet.
• Titanosauridae indet.
• Sauropoda indet.

Theropods

• Caenagnathidae indet.
• Troodontidae indet.^[6]
• Therizinosauria indet.^[6]
• Ornithomimidae indet.^[6]
• Tyrannosauroidea indet.

Pterosaurs

• Aralazhdarcho bostobensis^[7]
• Samrukia nessovi

Turtles

• Adocus foveatus
• Anatolemys maximus
• Khunnuchelys lophorhothon^[3]
• Lindholmemys gravis
• Shachemys baibolatica
• Trionyx kansaiensis, T. onomatoplokos, T. riabinini

Other reptiles

• Bishara backa

Amphibians

• Anura indet.
• Eoscapherpeton

Fish

• Gobiates sp.

Flora

• Ulmaceae indet.

See also

• List of dinosaur-bearing rock formations
• List of fossiliferous stratigraphic units in Kazakhstan
• Bissekty Formation
• Madygen Formation
• Karabastau Formation
• Kugitang Svita