# Gaogou Formation

The Gaogou Formation is a fossiliferous geological formation located in the Xixia Basin of China. The formation dates back to the Late Cretaceous (Cenomanian-Coniacian) and fossilized eggs of dinosaurs and turtles are commonly reported from the formation. Dinosaur taxa are also reported from the unit.

## Paleobiota of the Gaogou Formation

| Color key Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon | Notes Uncertain or tentative taxa are in small text; crossed out taxa are discredited. |

### Dinosaurs

| Genus | Species | Location | Stratigraphic Position | Material | Notes | Images |
| Baotianmansaurus | B. henanensis | Neixiang | | "Partial vertebrae and scapula." | A titanosauriform. | |
| Beibeilong | B. sinensis | Heimaogou | | "Embryonic skeleton with associated partial nest." | A large caenagnathid. | |

### Eggs

| Genus | Species | Location | Material | Notes |
| Dendroolithus | D. xichuanensis | Xichuan | "Eggshell fragments and collapsed eggs." | Dendroolithid eggs laid by ornithopods, sauropod or theropods. |
| Dendroolithus | Indeterminate | Xixia | "Intact eggs and egg clutches." | Dendroolithid eggs laid by ornithopods, sauropod or theropods. |
| Dictyoolithus | D. neixiangensis | Xixia | Not specified. | Dictyoolithid eggs. |
| Faveoloolithus | Indeterminate | Nanxiang | "Single egg." | Faveoloolithid egg. |
| Macroelongatoolithus | M. xixiaensis | Heimaogou | "Partial nest of 6-8 eggs, and eggshell fragments." | Elongatoolithid eggs laid by Beibeilong. |
| Macroelongatoolithus | M. xixiaensis | Neixiang, Xixia | "Isolated eggs and complete egg clutches." | Elongatoolithid eggs laid by caenagnathids. |
| Neixiangoolithus | N. yani | Neixiang | "Multiple egg clutches." | Testudoolithid eggs laid by a turtle. |
| Paraspheroolithus | P. cf. irenensis | Xixia | "Complete egg clutches." | Spheroolithid eggs. |
| Placoolithus | P. tumiaolingensis | Yunxian | "Several eggs and egg clutches." | Dendroolithid eggs laid by ornithopods, sauropod or theropods. |
| Prismatoolithus | P. gebiensis | Neixiang, Xixia | "Several egg clutches." | Prismatoolithid eggs laid by troodontids. |
| Youngoolithus | Y. xiaguanensis | Xixia | "Clutch with 4 eggs." | Youngoolithid eggs. |

### Flora

| Genus | Species | Location | Stratigraphic Position | Material | Notes | Images |
| Araucariaceae indet. | Indeterminate | Xixia | | "Amber pieces." | A conifer. | |
| Plantae indet. | Indeterminate | Not specified. | Upper Member | "Rhizoliths." | Root traces. | |

### Invertebrates

| Genus | Species | Location | Stratigraphic Position | Material | Notes |
| Beaconites | B. antarcticus | Not specified. | Upper Member | "Horizontal-overtical, straight to slightly curved, single, lined, meniscate burrows." | Invertebrate traces. |
| Beaconites | B. capronus | Not specified. | Upper Member | "Horizontal to vertical, straight to slightly curved, lined, unbranched burrows." | Invertebrate traces. |
| Beaconites | B. coronus | Not specified. | Upper Member | "Mostly horizontal to vertical, meniscate burrows." | Invertebrate traces. |
| Gastruichnus | G. xixiaensis | Not specified. | Upper Member | "Large, high dipping, slightly curved and unbranched burrow." | Traces made by molluscs. |
| Palaeophycus | P. heberti | Not specified. | Upper Member | "Straight to curved, horizontal to vertical, unbranched and lined burrows." | Invertebrate traces. |
| Palaeophycus | P. megas | Not specified. | Upper Member | "Curved, horizontal to vertical, unbranched and lined burrows." | Invertebrate traces. |
| Skolithos | S. linearis | Not specified. | | "Cylindrical burrows." | Invertebrate traces. |
| Skolithos | S. magnus | Not specified. | | "Cylindrical to subcylindrical, vertical and slightly curved burrows." | Invertebrate traces. |

### Turtles

| Genus | Species | Location | Stratigraphic Position | Material | Notes | Images |
| Yuchelys | Y. nanyangensis | Neixiang | | "Partial skeleton with carapace." | A nanhsiungchelyid. | |