Article · Wikipedia archive · Last revised Jul 28, 2026

Aitym Formation

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

Last revised
Jul 28, 2026
Read time
≈ 2 min
Length
349 w
Citations
17
Source
Aitym Formation
Stratigraphic range: ?Santonian
~
TypeGeological formation
OverliesBissekty Formation
AreaKyzylkum Desert
Thicknessup 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. wardi1 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. sp1 A asioryctithere
Kulbeckia Kulbeckia sp. cf. K. kulbecke1 A possible zalambdalestid
aff. Kulbeckia sp.1
Paranyctoides Paranyctoides sp. cf. P. aralensis1 A possible lipotyphlan
Paranyctoides sp.1
Eoungulatum E. sp. cf. E. kudukensis1 Zhelestid ungulatomorphs
Parazhelestes P. sp. cf. P. robustus1
P. sp. aff. P. minor1
Aspanlestes cf. A. sp.1

Molluscs

Molluscs of the Aitym Formation
Genus Species Location Notes Images
Placenticeras P. kyzylkumense1 A placenticeratid ammonite

Amphibians

Amphibians of the Aitym Formation
Genus Species Location Notes Images
Eoscapherpeton E. asiaticum2 A giant salamander
References

References