The Paoniuquan Formation is a geologic formation of Gansu, China preserving fossils from the late Oligocene, specifically the Tabenbulukian mammal age. Animals found in this formation are considered to be within the Yindirte Fauna.
The Paoniuquan Formation is named after a local spring found towards the southeast of Tiejianggou. It is the basal member of the Danghe area being made up of fine-grained, red mudstones and siltstones with a maximum depth of over 1000m.[1]
Though most units of the Danghe area represent lacustrine facies during the Oligocene, the top and bottom units of the Paoniuquan Formation represent more fluvial environments; both of these environments would have been in "low relief" terrain [2] During the deposition of the formation, there is no indication of the presence of intensive seismic activity in the western area Danghe Nan Shan.[3]
An anthracotheriid known from a m1/2 that was originally referred to Sivameryx. Ihough similar to P. hyopotamoides, the tooth has a lower crown than what is seen in the taxon.
An ochotonid with high-crowned dentition with distinct roots, the size and occlusion pattern of the teeth are identical to was is seen in the species.
D. pusillus
An ochotonid that is smaller in size than D. gobiensis along with larger crowns. The morphology of the teeth are identical to what is seen in the species.
A hyracodontid known from a fragmentary mandible with a high-crowned M1 with features similar to what is seen in Allacerops. The material from the formation is larger than other species documented in Central Asia.
A dipodid known from a m2 similar in morphology to L . huangheensis though with a few features different from the species like the shape in occlusal view.
A dipodid known from various parts of the dentition at the formation with dentition identical to what is seen in the species.
P. spp.
A dipodid known from teeth, most likely from different species. These being specifically similar to P. tangingoli and P. parvulus.
P. parvulus
A dipodid known from cheek teeth at the formation with cheek teeth identical to the species.
P. tangingoli
A dipodid known from cheek teeth along with a lower jaw, though the M3 of the material seen at the formation does have an initial double protoloph. This feature can most likely be attributed to individual variation within the species.
China