Batylykh Formation

The Batylykh Formation is a geological formation in Yakutia, Russia. It is of an uncertain Early Cretaceous age, probably dating between the Berriasian and the Barremian. It is the oldest unit of the 1500 m thick Sangar Series within the Vilyuy syneclise. The mudstones, sandstones and shales of the formation were deposited in a fluvial to lacustrine environment.

Fossil content
The formation is best known for the Teete locality, which has revealed remains of numerous vertebrates, including dinosaurs and mammals.

Fossils recovered from the formation include:
 * Mammaliaformes
 * Cryoharamiya
 * cf. Sineleutherus sp.
 * Docodonta indet.
 * Gobiconodon 
 * Sangarotherium
 * Xenocretosuchus
 * Khorotherium
 * Tritylodontidae 
 * Reptiles
 * Khurendukhosaurus
 * Ankylosauria indet.
 * Coelurosauria indet.
 * Lacertilia indet.
 * Macronaria indet.
 * Mesochelydia indet.
 * Stegosauria indet.
 * Theropoda indet.
 * Amphibians
 * Kulgeriherpeton ultimus
 * Anura indet.
 * Caudata indet.
 * Fish
 * Chondrostei indet.
 * Palaeoniscidae indet.
 * Insects
 * Crenoptychoptera gronskayae
 * Zhiganka comitans
 * Bivalves
 * Bivalvia indet.
 * Gastropods
 * Gastropoda indet.
 * Flora
 * Podocarpus multesima
 * Selaginella velata
 * Stereisporites compactus
 * S. congregatus
 * Tripartina variabilis
 * Ginkgocycadophytus sp.
 * Klukisporites sp.
 * Leiotriletes sp.
 * Ophyoglossum sp.
 * Piceapollenites sp.
 * Picea sp.
 * Pinus sp.
 * Selaginella sp.
 * Stereisporites sp.
 * Pinaceae indet.