The Barun Goyot Formation of Mongolia, is estimated to date back to the Campanian stage, between 84 and 70 million years ago of the Late Cretaceous period.
During the Late Cretaceous period, the land that is now the Barun Goyot Formation had an arid environment with fields of sand dunes and only intermittent streams.
It is slightly younger than the nearby Djadochta Formation, and seems to have been slightly wetter.
This formation is noteworthy for the exquisite preservation of small and fragile dinosaur skeletons, a rare occurrence considering that these fossils are typically broken up and dispersed when found in other rock formations.

 
The region that is preserved in the Barun Goyot Formation was home to the maniraptoran Hulsanpes perlei, the oviraptorids Conchoraptor gracilis and Ajancingenia yanshini, the alvarezsaurids Ceratonykus oculatus, Mononykus and Parvicursor remotus, the pachycephalosaur Tylocephale gilmorei, the ankylosaurs Saichania chulsanensis and Tarchia gigantea, and the ceratopsians Bagaceratops rozhdestvenskyi, Breviceratops kozlowskii, Lamaceratops tereschenkoi and Platyceratops tatarinovi.
The largest dinosaur among them was the titanosaur Quaesitosaurus orientalis.
It was observed that many of the same genera were present at the Barun Goyot and Djadochta Formations, though there was variation at the species level.
Vertebrates present in the Barun Goyot Formation included the primitive birds Gobipteryx minuta and Hollanda luceria and the lizards Estesia mongoliensis, Ovoo gurvel, Proplatynotia longirostrata and Gobiderma pulchrum.
The early mammals that were present in this region during the time of Avimimus were the placental mammals Asioryctes nemegetensis and Barunlestes butleri, the amphibian Gobiates khermeentsavi, the multituberculate mammals Catopsbaatar catopsaloides, Chulsanbaatar vulgaris and Nemegtbaatar gobiensis, and the marsupial mammal Asiatherium reshetovi and Deltatheridium pretrituberculare.
Numerous dinosaur eggshells found in this region support the presence of sauropods and maniraptors.
The Barun Goyot Formation of Mongolia, is estimated to date back to the Campanian stage, between 84 and 70 million years ago of the Late Cretaceous period. During the Late Cretaceous period, the land that is now the Barun Goyot Formation had an arid environment with fields of sand dunes and only intermittent streams. It is slightly younger than the nearby Djadochta Formation, and seems to have been slightly wetter. This formation is noteworthy for the exquisite preservation of small and fragile dinosaur skeletons, a rare occurrence considering that these fossils are typically broken up and dispersed when found in other rock formations.
 
The region that is preserved in the Barun Goyot Formation was home to the maniraptoran Hulsanpes perlei, the oviraptorids Conchoraptor gracilis and Ajancingenia yanshini, the alvarezsaurids Ceratonykus oculatus, Mononykus and Parvicursor remotus, the pachycephalosaur Tylocephale gilmorei, the ankylosaurs Saichania chulsanensis and Tarchia gigantea, and the ceratopsians Bagaceratops rozhdestvenskyi, Breviceratops kozlowskii, Lamaceratops tereschenkoi and Platyceratops tatarinovi. The largest dinosaur among them was the titanosaur Quaesitosaurus orientalis. It was observed that many of the same genera were present at the Barun Goyot and Djadochta Formations, though there was variation at the species level. Vertebrates present in the Barun Goyot Formation included the primitive birds Gobipteryx minuta and Hollanda luceria and the lizards Estesia mongoliensis, Ovoo gurvel, Proplatynotia longirostrata and Gobiderma pulchrum. The early mammals that were present in this region during the time of Avimimus were the placental mammals Asioryctes nemegetensis and Barunlestes butleri, the amphibian Gobiates khermeentsavi, the multituberculate mammals Catopsbaatar catopsaloides, Chulsanbaatar vulgaris and Nemegtbaatar gobiensis, and the marsupial mammal Asiatherium reshetovi and Deltatheridium pretrituberculare. Numerous dinosaur eggshells found in this region support the presence of sauropods and maniraptors.
Avimimus