Aitym Formation

Aitym Formation
Stratigraphic range: ?Santonian ~86–83  Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Overlies	Bissekty Formation
Area	Kyzylkum Desert
Thickness	up to
Location
Aitym Formation (Uzbekistan)

The Aitym Formation is a geological formation in Uzbekistan which possibly dates to the Santonian stage of the Late Cretaceous period. ^[1]

The formation has not been precisely dated. However, certain fossils suggest the formation was deposited during the Santonian stage of the Late Cretaceous period. ^[1]

Fossil content

A diverse fauna has been unearthed from the Aitym Formation including oysters, ammonites and many marine vertebrates, including an abundant assemblage of chondrichthyans (cartilaginous fish), a rarer assemblage of osteichthyans (bony fish), and rather infrequent finds of plesiosaurs, and sea turtles. Terrestrial vertebrate remains are extremely rare in the formation. A few bones of salamanders, lizards, crocodiles, possibly terrestrial turtle remains, dinosaurs (including birds), and mammals have been found in the formation. ^[1]

Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon		Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Mammals

Mammals of the Aitym Formation
Genus	Species	Location	Notes	Images
Uzbekbaatar	U. wardi [1]		A cimolodontan multituberculate
Shalbaatar	cf. S. sp. [1]		A spalacotheriid symmetrodont
Deltatherus	cf. D. sp. [1]		A deltatheroidan; reclassified later as Sulestes , as the two genera have been synonymized
Daulestes	aff. D. sp [1]		A asioryctithere
Kulbeckia	Kulbeckia sp. cf. K. kulbecke [1]		A possible zalambdalestid
	aff. Kulbeckia sp. [1]
Paranyctoides	Paranyctoides sp. cf. P. aralensis [1]		A possible lipotyphlan
	Paranyctoides sp. [1]
Eoungulatum	E. sp. cf. E. kudukensis [1]		Zhelestid ungulatomorphs
Parazhelestes	P. sp. cf. P. robustus [1]
	P. sp. aff. P. minor [1]
Aspanlestes	cf. A. sp. [1]

Molluscs

Molluscs of the Aitym Formation
Genus	Species	Location	Notes	Images
Placenticeras	P. kyzylkumense [1]		A placenticeratid ammonite

Amphibians

Amphibians of the Aitym Formation
Genus	Species	Location	Notes	Images
Eoscapherpeton	E. asiaticum [2]		A giant salamander

References

1. Averianov, A (2003). "Mammals from the Upper Cretaceous Aitym Formation, Kyzylkum Desert, Uzbekistan". Cretaceous Research. 24 (2): 171–191. Bibcode:2003CrRes..24..171A. doi:10.1016/S0195-6671(03)00037-5.
2. Skutschas, Pavel P.; Saburov, Pavel G.; Boitsova, Elizaveta A.; Kolchanov, Veniamin V. (2019). "Ontogenetic changes in long-bone histology of the cryptobranchid Eoscapherpeton asiaticum (Amphibia: Caudata) from the Late Cretaceous of Uzbekistan". Comptes Rendus Palevol. 18 (3): 306–316. Bibcode:2019CRPal..18..306S. doi:10.1016/j.crpv.2019.02.002.