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. New uranium-lead dates reveal the formation is deposited in the Aptian stage of the Early Cretaceous. Fossils of Microraptor and Jeholornis are from the Jiufotang.

Fossil content

Mammaliamorphs

Several mammaliamorph specimens have been found from the Jiufotang, but only a few have been formally described and named.

Genus	Species	County	Member	Material	Notes
Cokotherium	C. jiufotangensis			Partial skeleton	A eutherian
Fossiomanus	F. sinensis			A nearly complete skeleton	A tritylodontid cynodont, likely the youngest known non-mammalian synapsid
Liaoconodon	L. hui			A 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.

Saurischians

Skeletal and dental remains are known, the latter was assigned to an indeterminate titanosauriform.

Non-ornithothoracean theropods

A large theropod tooth representing a distinct taxon from Sinotyrannus is known.

Genus	Species	County	Member	Material	Notes	Images
Chongmingia	C. zhengi			A partial skeleton with preserved soft tissues	A jinguofortisid avialan
Confuciusornis	C. sanctus				A primitive short-tailed avialan. Also present in the Yixian Formation
Confuciusornis	C. jianchangensis	Liaoning
Cratonavis	C. zhui	Jianchang		A complete skeleton with preserved feathers	A jinguofortisid avialan
Dalianraptor	D. cuhe				Nomen dubium, named from a forged artificially assembled specimen.
Jeholornis	J. prima				A jeholornithiform avialan, also present in the Yixian Formation
Jeholornis	J. palmapenis				A jeholornithiform avialan
Kompsornis	K. longicaudatus			"Nearly complete specimen".	A jeholornithiform avialan
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.
Neimengornis	N. rectusmim				A jeholornithiform avialan
Omnivoropteryx	O. sinousaorum				An omnivoropterygiform avialan
Sapeornis	S. angustis			"Nearly complete skeleton without skull."	An omnivoropterygiform, a primitive short-tailed avialan
Sapeornis	S. chaoyangensis				An omnivoropterygiform, a primitive short-tailed avialan
Shenshiornis	Shenshiornis primita				An omnivoropterygiform avialan
Similicaudipteryx	S. yixianensis				An oviraptorosaur
Sinotyrannus	S. kazuoensis				A tyrannosauroid
Wulong	W. bohaiensis	Chaoyang, Liaoning		Complete articulated skeleton.	A dromaeosaurid