[5] In 2008, a team of Canadian, American, and Mongolian paleontologists headed by Phil Currie reported in 2006 an extensive bonebed of Avimimus sp.

The team also suggests that the individuals were found together because they were gregarious in life, providing possible indications that Avimimus formed age-segregated groups for either lekking or flocking purposes.

The adults showed a greater degree of skeletal fusion in the tarsometatarsus and tibiotarsus, and also more prominent muscle scars.

[1] The foramen magnum, the hole allowing the spinal cord to connect with the brain, was proportionally large in Avimimus.

Unlike oviraptorids and caenagnathids, the back vertebrae lack openings for air sacs, suggesting that Avimimus is more primitive than these animals.

Avimimus was originally suggested to be a very close relative of birds, given its unique suite of bird-like features not known in other dinosaurs at the time.

Most modern scientists find that Avimimus in fact belongs to a diverse group of bird-like dinosaurs more primitive than Archaeopteryx, the oviraptorosaurs.

Rinchenia Citipati Chirostenotes Elmisaurus Hagryphus Ingenia Heyuannia Conchoraptor Khaan The Barun Goyot Formation of Mongolia, is estimated to date back to the Campanian stage, between 84 and 70 million years ago[15] of the Late Cretaceous period.

[16] 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.

[17] 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.

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.

[18] 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.