The primary fossil-producing outcrop of the Miaogou Formation is the Maortu locality, which was discovered in 1959 by a joint expedition of Chinese and Russian paleontologists.

[4] While the Miaogou Formation has not been absolutely dated, estimates based on charophytan, stratigraphic, and sedimentological studies have proposed a Barremian–Albian age range.

[5] However, a more narrow range (around Aptian-Albian) is implied based on the fossil animals found in the formation, which are inconsistent with Chinese Barremian faunas such as those associated with the Jehol Biota.

[6] Gobisaurus G. domoculus Maortu locality, Chilantai A skull, with undescribed postcranial remains belonging to the same individual[7] An ankylosaurid closely related to Shamosaurus; originally interpreted as from the nearby Ulansuhai Formation[4]

Probactrosaurus P. gobiensis Maortu locality, Chilantai Partial skulls and skeletons[8] A hadrosauroid ornithopod; originally interpreted as from the nearby Dashuigou Formation[4]