| Qingtoushan Formation | |
| Type: | Geological formation |
| Age: | Middle Permian, |
| Period: | Roadian |
| Otherlithology: | Mudstone |
| Namedby: | Liu et al |
| Region: | Gansu |
| Country: |  China |
| Underlies: | Sunan Formation |
| Overlies: | Yaogou Formation |
| Thickness: | Over 300 metres |
| Extent: | Qilian Mountains |
| Year Ts: | 2012 |
The Qingtoushan Formation is a Middle Permian-age geologic formation in the Qilian Mountains of Gansu, China. It is known for its diverse tetrapod fauna known as the Dashankou fauna, which likely dates to the Roadian, and includes some of the oldest known therapsids.[1] This formation was previously erroneously named as the Xidagou Formation, a name which applies to otherwise Triassic strata in the northern Qillian Mountains. The formation is over 300 metres thick, and primarily consists of purple-red coarse sandstones, with minor purple mudstone.[2]
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images | |
|---|---|---|---|---|---|---|---|
| Biseridens[3] | B. qilianicus | A well-preserved skull | An anomodont | ||||
| Sinophoneus[4] | S. yumenensis | A single skull (GMV 1601) | An anteosaurid dinocephalian | ||||
| Stenocybus | S. acidentatus | A skull (IGCAGS V 361) and fragmentary jaw bones | Jr. synonym of Sinophoneus yumenensis | ||||
| Raranimus | R. dashankouensis | Dashankou locality | A partial skull | A basal therapsid. |
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images | |
|---|---|---|---|---|---|---|---|
| Belebey | B. zhengi | A bolosaurid parareptile | |||||
| Gansurhinus | G. qingtoushanensis | A captorhinid |
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images | |
|---|---|---|---|---|---|---|---|
| Phratochronis | P. qilianensis | A Chroniosuchid | |||||
| Ingentidens | I. corridoricus | A Chroniosuchid |