Image: Bayan Shireh Formation Fauna

Description: Diagram featuring all the current known Dinosauria from the Bayan Shireh Formation. The Bayan Shireh (or Baynshire) Formation, is a geological formation located in Mongolia, it was first described and established by Vasiliev et al. in 1959.[1] Dating back to the Cenomanian-Santoninan ages (102 million to 86 million years ago)[2][3][4], it is primarly composed by varicoloured claystones and sandstones with some conglomerates and mudstones[1] and preserves a rich diversity of paleofauna composed by both dinosaur and non-dinosaur vertebrates. There are five indeterminate or unnamed dinosaur genera: an U. Caenagnathid (known from Tsagan Teg)[5], U. Hadrosauroid (known from Baynshire and Khar Teg)[6], U. Therizinosaur (known from Ulribe Khuduk)[7], U. Titanosaur (known from Bor Guvé)[8] and U. Velociraptorine (known from Shine Us Khuduk and Tel Ulan Chaltsai).[9]The Bayan Shireh Formation has been divided into two boundary strata: Lower and Upper; with that faunas being older or younger.[10][11][3] Tsogtbaatar et al. 2019 published a map featuring the fossil locations in Mongolia, the localities at Bayan Shireh represent Early and Late Cretaceous boundary.[12] Following this boundary division and map, the depicted Dinosauria can be established as: Upper Bayan Shireh: Achillobator[13], Alectrosaurus[14], Amtocephale[15], Erketu[16], Erlikosaurus[17], Garudimimus[18][19][20], Gobihadros[12], Graciliceratops[21], Segnosaurus[22], Talarurus[23][24][25], Tsagantegia[26], Unnamed Caenagnathid, U. Hadrosauroid, U. Therizinosaur, U. Titanosaur and U. Velociraptorine. Lower Bayan Shireh: Enigmosaurus[27][17], Segnosaurus (this taxon has been recovered from upper and lower localities) and U. Velociraptorine (the same case of the latter). NOTE: Amtosaurus and Maleevus were excluded from this chart, due to having very sparce remains and being invalid genera.[28] Based on remains, Gobihadros is an immature animal, and being a hadrosaur, it is likely that it grown much larger.[12] >>> As an update of this previous statement, in a recent paper, it has been confirmed that Gobihadros reached larger sizes, evidenced on multiple specimens.[6]
Title: Bayan Shireh Formation Fauna
Credit: Own work
Author: PaleoNeolitic
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License: CC BY-SA 4.0
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