Jiufotang Formation
The Jiufotang Formation is an Early Cretaceous geological formation in Chaoyang, Liaoning which has yielded fossils of feathered dinosaurs, primitive birds, pterosaurs, and other organisms. It is a member of the Jehol group. The exact age of the Jiufotang has been debated for years, with estimates ranging from the Late Jurassic to the Early Cretaceous. He et al. used argon - isotope radiometry to confirm biostratigraphic age estimates. They confirmed an Early Cretaceous, Aptian age for the Jiufotang Formation, 120.3 +/-0.7 million years ago. Fossils of Microraptor and Jeholornis are from the Jiufotang.
Fossil content
Choristoderans
Fish
Mammals
Several mammal specimens have been found from the Jiufotang, but only one has been formally described and named.| Genus | Species | County | Member | Abundance | Notes |
| Liaoconodon | L. hui | Nearly complete skeleton | A eutriconodont | ||
| Unnamed mammal | Unnamed | Partial remains including a foot and fragments of the skull | A mammal similar to Eomaia and Sinodelphys from the Yixian Formation. Found as stomach contents of Microraptor zhaoianus. |
Ornithischians
Pterosaurs
Saurischians
A large titanosaur is present in the formation.Enantiornithines
Euornithines
Misc theropods
| Genus | Species | County | Member | Material | Notes | Images | - |
Confuciusornis | C. sanctus | A primitive short-tailed bird. Also present in the Yixian Formation | - | ||||
Confuciusornis | C. jianchangensis | Liaoning | - | ||||
Dalianraptor | D. cuhe | Nomen dubium, named from a forged artificially assembled specimen. | - | ||||
Jeholornis | J. prima | A basal avialan, also present in the Yixian Formation | - | ||||
Jeholornis | J. palmapenis | A basal avialan | - | ||||
Kompsornis | K. longicaudatus | "Nearly complete specimen". | A long tailed avialan, related to Jeholornis. | ||||
Microraptor | M. gui | Shangheshou Bed | Extremely common | Could be synonym of Microraptor zhaoianus | - | ||
Microraptor | M. zhaoianus | Shangheshou Bed | "At least partial semiarticulated postcrania and several skulls." Feathered integument is also preserved. | A dromaeosaurid. | - | ||
Omnivoropteryx | O. sinousaorum | An omnivoropterygiform | - | ||||
Sapeornis | S. angustis | "Nearly complete skeleton without skull." | An omnivoropterygiform, a primitive short-tailed bird | - | |||
Sapeornis | S. chaoyangensis | An omnivoropterygiform, a primitive short-tailed bird | - | ||||
Shenshiornis | Shenshiornis primita | An omnivoropterygiform | - | ||||
Similicaudipteryx | S. yixianensis | An oviraptorosaur | - | ||||
Sinotyrannus | S. kazuoensis | A tyrannosauroid | - | ||||
Zhongjianornis | Z. yangi | A primitive short-tailed bird | - | ||||
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