Paleobiota of the Yixian Formation

The Yixian Formation (simplified Chinese: 义县组; traditional Chinese: 義縣組; pinyin: Yìxiàn zǔ) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans about 1.6 million years during the early Cretaceous period (Barremian-Aptian stage). It is known for its fossils, listed below.

Ordosemys liaoxiensis and Psittacosaurus preserved together

The Yixian Formation is divided into the following subunits: (ages from Zhong et al., 2021^[1] unless otherwise noted)

• Upper Yixian (124.1 Ma) ("Jingangshan Bed") ("Dawangzhangzi Bed")
• Upper Lava Unit
• Jianshangou Unit (125.46 Ma)
• Lower Lava Unit
• Lujiatun Unit (125.76–125.68 Ma)

Sauropods

Genus	Species	County	Member	Material	Notes	Images
Dongbeititan	D. dongi	Beipiao	Jianshangou Bed	Partial postcrania[2]	A basal titanosauriform	Euhelopus
cf. Euhelopus	cf. E. sp.		Lujiatun Bed	Isolated teeth[3][4]	A basal titanosauriform
Liaoningotitan	L. sinensis			nearly complete skeleton[5]	A basal titanosauriform
Ruixinia	R. zhangi	Beipiao		A partial articulated skeleton[6]	A somphospondylan titanosauriform
Sauropoda spp.			Lujiatun & Jianshangou Beds	Isolated vertebrae and teeth[7][4]	One or more species of sauropods, possibly titanosaurs, have been recovered from the Yixian Formation, though most remain undescribed[3]

Ornithischians

The dinosaurs listed below were compiled in a survey by Xu and Norell in 2006, unless otherwise noted.^[7]

Ankylosaurs

Genus	Species	County	Member	Material	Notes	Images
Liaoningosaurus	L. paradoxus	Yixian	Dawangzhangzi Bed	"Partial skull [and] skeleton."[8]	A small ankylosaur	Liaoningosaurus

Ceratopsians

Genus	Species	County	Member	Material	Notes	Images
Liaoceratops	L. yanzigouensis	Beipiao	Lujiatun Bed	"[Two] nearly complete skulls, juvenile to adult."[9]	A ceratopsian	Liaoceratops Psittacosaurus
Psittacosaurus	P. lujiatunensis	Beipiao	Lujiatun & Jianshangou Beds	Thousands of specimens in the Lujiatun Bed, somewhat less common in the Jianshangou Bed	A ceratopsian

Ornithopods

Genus	Species	County	Member	Material	Notes	Images
Bolong	B. yixianensis		Jianshangou Bed	A nearly complete skeleton.	An iguanodontian ornithopod	Bolong Jeholosaurus Jinzhousaurus
Changmiania[10]	C. liaoningensis		Lujiatun Bed	Two nearly complete skeletons	A basal ornithopod that may have dug burrows
Jeholosaurus	J. shangyuanensis	Beipiao	Lujiatun Bed	"Skull with associated vertebrae and hindlimb, skull with cervical vertebrae."[11]	An ornithopod
Jinzhousaurus	J. yangi	Yixian	Dawangzhangzi Bed	"Nearly complete skull and skeleton."[12]	An ornithopod

Theropods

The dinosaurs listed below were compiled in a survey by Xu and Norell in 2006, unless otherwise noted.^[7]

Avialans

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.

Genus	Species	County	Member	Material	Notes	Images
Abitusavis[13]	A. lii	Ningcheng		"Nearly complete skeleton."[13]		Changchengornis Confuciusornis sanctus Eogranivora Hongshanornis Liaoningornis Liaoxiornis Shanweiniao Yixianosaurus
Archaeorhynchus	A. spathula		Dawangzhangzi Bed		An early, advanced short-tailed bird (ornithuran)[14]
Changchengornis[15]	C. hengdaoziensis[15]		Jianshangou Bed	"Nearly complete skeleton."[15]	A confuciusornithid
Confuciusornis	C. chuonzhous				Junior synonym of Confuciusornis sanctus[16]
	C. dui[17]		Jianshangou Bed	"[Two] skeletons."[17]
	C. feducciai[18]		Jianshangou Bed
	C. sanctus[17]		Jianshangou and Dawangzhangzi Beds	"Hundreds of complete skeletons."[17]	A primitive short-tailed bird (pygostylian), also present in the Jiufotang Formation
	C. suniae				Junior synonym of Confuciusornis sanctus[16]
Dalingheornis	D. liweii		Dawangzhangzi Bed		An Enantiornithine[19]
Eoenantiornis	E. buhleri		Jianshangou Bed	"Nearly complete skeleton."[20]	An entantiornithine
Eogranivora	E. edentulata		Dawangzhangzi Bed	"nearly complete skeleton with skull"[21]	An ornithuromorph
Iteravis	I. huchzermeyeri				An ornithuromorph
Jinzhouornis	J. yixianensis		Jianshangou Bed		A pygostylian, a junior synonym of Confuciusornis sanctus[22]
	J. zhangjiyingia		Jianshangou Bed		Junior synonym of C. sanctus
Jixiangornis	J. orientalis		Jianshangou Bed		A basal avialan, also present in the Jiufotang Formation[23]
Hongshanornis	H. longicresta		Jianshangou and Dawangzhangzi Beds[24]	4 specimens[24]	An ornithuromorph[25]
Jibeinia	J. luahera				Previously regarded as Yixian, horizon reassigned to the Huajiying Formation by Jin et al., 2008.[26]
Liaoningornis	L. longidigitris		Lujiatun Bed	"Partial skeleton."[27]	An enantiornithine.[28]
Liaoxiornis	L. delicatus		Dawangzhangzi Bed		Considered a nomen dubium because the name is based on remains of a hatchling entantiornithine and cannot be confidently matched with the adult form.[29]
Lingyuanornis	L. parvus		Dawangzhangzi Bed		Junior objective synonym of Liaoxiornis delicatus, a nomen dubium.[29]
Longicrusavis	L. houi		Dawangzhangzi Bed		An ornithuromorph[25]
Longirostravis	L. hani		bed unknown		An enantiornithine
Protopteryx	P. fengningensis				Previously regarded as Yixian, horizon reassigned to the Huajiying Formation by Jin et al., 2008.[26]
Mirusavis	M. parvus			Partial skeleton.[30]	An immature female enantiornithine preserved with medullary bone tissue.[30]
Sapeornis[31]	S. chaoyangensis			Nearly comeplete skeleton.[31]	A subadult omnivoropterygid with preserved feathers.[31]
Shanweiniao	S. cooperorum		Dawangzhangzi Bed		An enantiornithine.[32]
Vescornis	V. hebeiensis				Previously regarded as Yixian, horizon reassigned to the Huajiying Formation by Jin et al., 2008.[26]
Yixianosaurus	Y. longimanus		Dawangzhangzi Bed		An anchiornithid
Zhongornis	Z. haoae		Dawangzhangzi Bed		A primitive avialan with a short but non-pygostylian tail[33]

Compsognathids

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.

Genus	Species	County	Member	Material	Notes	Images
Huadanosaurus[34]	H. sinensis		Dawangzhangzi Bed	A nearly complete specimen missing the feet and end of the tail	A compsognathid	Huadanosaurus Sinocalliopteryx gigas Sinosauropteryx lingyuanensis Sinosauropteryx prima
Huaxiagnathus	H. orientalis	Beipiao	Jianshangou Bed		A compsognathid
Sinocalliopteryx	S. gigas	Beipiao	Jianshangou Bed		A large compsognathid
Sinosauropteryx	S. lingyuanensis[34]		Dawangzhangzi Bed	A nearly complete specimen	A compsognathid
	S. prima	Beipiao & Lingyuan	Jianshangou & Dawangzhangzi Beds	Four nearly complete specimens[35][36]	A compsognathid. The first non-avian dinosaur found with feather impressions.
	S.? sp.	Beipiao	Jianshangou Bed	One specimen (GMV 2124) with partial skull, postcrania, and preserved feathers	An unnamed coelurosaur originally described as a specimen of Sinosauropteryx, later suggested to be a new genus and species,[37] probably a tyrannosauroid.[34]

Dromaeosaurs

Genus	Species	County	Member	Material	Notes	Images
Changyuraptor[38]	C. yangi	Jianchang		A complete articulated specimen with extensive feathering.[38]	A dromaeosaurid	Changyuraptor Graciliraptor Sinornithosaurus millenii Tianyuraptor Zhenyuanlong Zhongjianosaurus
Graciliraptor	G. lujiatunensis	Beipiao	Lujiatun Bed	An incomplete specimen.	A dromaeosaurid
Sinornithosaurus	S. haoiana	Yixian	Dawangzhangzi Bed		Might be a junior synonym of Sinornithosaurus millenii.
	S. millenii	Beipiao	Jianshangou Bed	Three specimens with skulls and postcrania, two with preserved feathers.[39] Feathered integument is also preserved.[39][40]	A dromaeosaurid, the first ever found with feather impressions.
Tianyuraptor	T. ostromi	Lingyuan	Dawangzhangzi Bed		A dromaeosaurid
Zhenyuanlong[41]	Z. suni	Jianchang		One nearly complete skeleton with preserved feathers, including long tail feathers and large wing feathers.	A dromaeosaurid
Zhongjianosaurus[42]	Z. yangi	Lingyuan		A partial skeleton includes an arm, legs, vertebrae, ribs, and most of the tail.[42]	A microraptorian dromaeosaurid with very long legs.[42]
Unnamed dromaeosaurid	Specimen NGMC 91	Lingyuan	Dawangzhangzi Bed	Complete specimen with feather imprints	A juvenile dromaeosaurid that may be a specimen of Sinornithosaurus millenii.[43][44] Informally nicknamed "Dave".

Ornithomimosaurs

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.

Genus	Species	County	Member	Material	Notes	Images
Hexing	H. qingyi	Beipiao	Lujiatun		A primitive ornithomimosaur[45]	Shenzhousaurus
Shenzhousaurus	S. orientalis	Beipiao	Lujiatun Bed	"Articulated skull and incomplete skeleton."[46]	A primitive ornithomimosaur

Oviraptorosaurs

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.

Genus	Species	County	Member	Material	Notes	Images
Caudipteryx	C. dongi	Beipiao	Jianshangou Bed	"[One] partial postcranium with feather imprints."[47]	An oviraptorosaur	Caudipteryx zoui Incisivosaurus Protarchaeopteryx
	C. zoui	Beipiao	Jianshangou Bed	Common, only over a small region
	C. sp.[48]
Incisivosaurus	I. gauthieri	Beipiao	Lujiatun Bed	"[One] skull [and a] partial cervical."[47]	An oviraptorosaur
Ningyuansaurus	N. wangi			Complete skeleton with feather impressions.[49]	An oviraptorosaur
Protarchaeopteryx	P. robusta	Beipiao	Jianshangou Bed	"Nearly complete skull and skeleton, at least [two] individuals."[50]	A possible relative of Incisivosaurus
Similicaudipteryx	S. yixianensis			Two specimens	An oviraptorosaur, also present in the Jiufotang Formation[51]
Xingtianosaurus	X. ganqi	Liaoning	Dakangpu Bed	One nearly complete specimen (IVPP V13390), minus the head	An oviraptorosaur[52]

Therizinosaurs

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.

Genus	Species	County	Member	Material	Notes	Images
Beipiaosaurus	B. inexpectus	Beipiao	Jianshangou Bed	"Incomplete skeleton with integument."[53]	A therizinosaur	Beipiaosaurus Jianchangosaurus
Jianchangosaurus	J. yixianensis	Jianchang		A nearly complete juvenile specimen with feather impressions.[54]	A therizinosaur

Troodontids

Genus	Species	County	Member	Material	Notes	Images
Daliansaurus	D. liaoningensis	Beipiao	Lujiatun Bed	A very complete specimen.[55]	A troodontid	Daliansaurus Jianianhualong Liaoningvenator Mei Sinovenator Sinusonasus
Jianianhualong	J. tengi	Beipiao	Dawangzhangzi Bed	A very complete specimen with feather impressions.[56]	A troodontid
Liaoningvenator	L. curriei	Beipiao		A very complete specimen.	A troodontid
Mei	M. long	Beipiao	Lujiatun Bed		A small troodontid fossilized in a sleeping position
Sinovenator	S. changii	Beipiao	Lujiatun Bed	Three specimens with partial skulls and postcrania.[57][58] Hundreds of additional specimens known but undescribed.	A troodontid
Sinusonasus	S. magnodens	Beipiao	Lujiatun Bed		A troodontid
Undescribed deinonychosaur/possible troodontid			Dawangzhangzi Bed	One specimen with feather imprints	A possible troodontid.[59]
Undescribed troodontid	Specimen CAGS-IG01-004		Lujiatun Bed	Skull and partial skeleton	A troodontid similar to Mei.[60]

Tyrannosaurs and other theropods

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.

Genus	Species	County	Member	Material	Notes	Images
Dilong	D. paradoxus	Beipiao	Lujiatun & Jianshangou Bed	Rare	A tyrannosauroid	Dilong Yutyrannus
Grallator			lower Jianshangou Bed		Footprints belonging to the Grallator form taxon, belonging to a small theropod. Of known Yixian theropods, the footprints most closely match Caudipteryx.[61]
Raptorex	R. kriegsteini				A tyrannosaurid, probably from higher Mongolian strata.
Scansoriopteryx	S. heilmanni				Initially reported from the Dawangzhangzi Bed, probably from the Daohugou Beds instead.[62]
Yutyrannus	Y. huali		Unknown	Three nearly complete skeletons of various ages	A large tyrannosauroid[63]
Unnamed theropod	Not yet described	Yixian	Lujiatun Bed	Partial post-cranial skeleton[64]	A possible carnosaur[65]

Pterosaurs

The pterosaurs listed below were compiled in a survey by Wang and Zhou in 2006, unless otherwise noted.^[66]

Genus	Species	County	Member	Material	Notes	Images
Beipiaopterus	B. chenianus		Jianshangou Bed		A ctenochasmatid	Feilongus Gladocephaloideus Haopterus Moganopterus Ningchengopterus
Boreopterus	B. cuiae		Jianshangou Bed		A boreopterid
Cathayopterus	C. grabaui		Dawangzhangzi Bed		A ctenochasmatid
Dendrorhynchoides[67]	D. curvidentatus				An anurognathid
Elanodactylus[68]	E. prolatus		Jianshangou Bed[69]		A ctenochasmatid
Eopteranodon	E. lii[70]	Beipiao			A tapejarid
	E. yixianensis[71]	Beipiao	Jianshangou Bed		A tapejarid
Eosipterus	E. yangi		Jianshangou Bed		A ctenochasmatid
Gegepterus[72]	G. changae[69]		Jianshangou Bed[69]		A ctenochasmatid
Gladocephaloideus	G. jingangshanensis		Jianshangou Bed		A ctenochasmatid
Haopterus	H. gracilis		Jianshangou Bed		An ornithocheirid
Luchibang[73][74]	L. xingzhe			One partial skull	An istiodactylid
Moganopterus	M. zhuiana		Lujiatun bed?		A ctenochasmatid
Ningchengopterus	N. liuae		Jianshangou or Dawangzhangzi bed		A pterodactyloid[75]
Nurhachius	N. sp.		Jingangshan Member[76]	An incomplete specimen[76]	An istiodactylid
Pterofiltrus	P. qiui		Jianshangou Bed		A ctenochasmatid[69]
Yixianopterus	Y. jingangshanensis				An istiodactyliform
Zhenyuanopterus	Z. longirostris		Jianshangou Bed		A boreopterid.[77] May be adult form of Boreopterus.[78]

Misc. reptiles

Choristoderans

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.

Genus	Species	County	Member	Material	Notes	Images
Hyphalosaurus	H. lingyuanensis		Dawangzhangzi Bed			Hyphalosaurus baitaigouensis Monjurosuchus splendens
	H. baitaigouensis		Jingangshan Bed	Thousands of specimens
Monjurosuchus	M. splendens		Dawangzhangzi Bed
Sinohydrosaurus	S. lingyuanensis		Dawangzhangzi Bed		Junior synonym of Hyphalosaurus lingyuanensis

Lizards

Genus	Species	County	Member	Material	Notes	Images
Dalinghosaurus	D. longidigitus		Jianshangou Bed		A lizard related to shinisaurs	Dalinghosaurus Xianglong
Liushusaurus	L. acanthocaudata[79]		Jianshangou or Dawangzhangzi bed		A lizard related to geckos and skinks
Xianglong	X. zhaoi		Jianshangou Bed		A gliding lizard related to chameleons and dragon lizards
Yabeinosaurus	Y. tenuis		Dawangzhangzi & Jingangshan Beds		A lizard related to geckos and skinks

Turtles

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.

Genus	Species	County	Member	Material	Notes	Images
Manchurochelys	M. liaoxiensis[80]		Jianshangou Bed		Reclassified as Ordosemys liaoxiensis[81]	Ordosemys
	M. manchoukuoensis[16]		Jingangshan Bed
Ordosemys	O. liaoxiensis[81]		Jianshangou Bed

Mammals

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.

The mammals listed below were compiled in a survey by Meng and colleagues in 2006, unless otherwise noted.^[82]

Genus	Species	County	Member	Material	Notes	Images
Acristatherium	A. yanensis[83]	Beipiao	Lujiatun Bed		A eutherian	Eomaia Gobiconodon zofiae Jeholodens Repenomamus robustus Yanoconodon
Akidolestes	A. cifellii	Lingyuan	Dawangzhangzi Bed		A spalacotheriid "symmetrodont"
Ambolestes[84]	A. zhoui	Nincheng	Jianshangou Bed		A eutherian
Chaoyangodens[85]	C. lii	Lingyuan	Dawangzhangzi Bed		A eutriconodont
Eomaia	E. scansoria	Lingyuan	Dawangzhangzi Bed		A tribosphenidan, possibly a eutherian or stem-therian
Gobiconodon	G. zofiae	Beipiao	Lujiatun Bed		A gobiconodont
	G. luoianus[86]		Lujiatun Bed		A gobiconodont; junior synonym of G. zofiae
Jeholodens	J. jenkinsi	Chaoyang	Jianshangou Bed		A eutriconodont
Juchilestes[87]	J. liaoningensis	Beipiao	Lujiatun Bed		An amphidontid
Jueconodon[88]	J. cheni				A eutriconodont
Maotherium	M. sinensis	Chaoyang	Jianshangou Bed		A zhangeotheriid "symmetrodont"
	M. asiaticus[89]	Beipiao	Lujiatun Bed		A zhangeotheriid "symmetrodont"
Meemannodon	M. lujiatunensis	Beipiao	Lujiatun Bed		A gobiconodont
Origolestes	O. lii				A zhangeotheriid "symmetrodont"
Ningchengodon	N. foxi[90]	Ningcheng	Ningcheng Basin	A partial right dentary.	A symmetrodont.
Repenomamus	R. giganticus	Beipiao	Lujiatun Bed		A gobiconodont
	R. robustus	Beipiao	Lujiatun Bed		A large gobiconodont, which ate small dinosaurs
Sinobaatar	S. lingyuanensis	Lingyuan	Jianshangou and Dawangzhangzi Beds		A multituberculate
Sinodelphys	S. szalayi	Lingyuan	Dawangzhangzi Bed		A therian, initially interpreted as a metatherian and later reinterpreted as a eutherian
Yanoconodon[91]	Y. allini[91]	Fengning[91]			A eutricondodont
Zhangheotherium	Z. quinquecuspidens	Chaoyang	Jianshangou Bed		A zhangeotheriid "symmetrodont"

Amphibians

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.

Genus	Species	County	Member	Material	Notes	Images
Callobatrachus	C. sanyanensis	Sihetun	Jianshangou Bed		Junior synonym of Liaobatrachus	Liaobatrachus
Laccotriton	L. subsolanus	Paozhanggou	Fengshan Bed		A urodelan
Liaobatrachus	L. grabaui	Sihetun	Jianshangou Bed		A spadefoot toad
	L. zhaoi	Beipiao & Heitizigou	Lujiatun Bed & Jianshangou Bed		A spadefoot toad
Mesophryne	M. beipiaoensis	Beipiao & Heitizigou	Lujiatun Bed & Jianshangou Bed		Junior synonym of Liaobatrachus
Sinerpeton	S. fengshanensis	Paozhanggou	Fengshan Bed		A urodelan

Fish

Genus	Species	County	Member	Abundance	Notes	Images
Hybodontoidea indet.	Family, genus and species indeterminate				An elasmobranch known from a single dorsal fin spine[92]	Lycoptera Mesomyzon Protopsephurus Sinamia
Lycoptera	L. davidi		Jianshangou & Dawangzhangzi Beds	Also present in the Jiufotang Formation & Huajiying Formation	An osteoglossiform
	L. muroii		Jingangshan Bed
	L. sinensis		Jianshangou Bed
Mesomyzon	M. mengae				A lamprey
Peipiaosteus	P. pani		Jianshangou & Dawangzhangzi Bed	Also present in the Jiufotang Formation	A peipiaosteid fish related to sturgeons
Protopsephurus	P. liui		Dawangzhangzi Bed	Also present in the Jiufotang & Huajiying Formations	A paddlefish
Sinamia	S. liaoningensis		Jianshangou Bed		A bowfin
Yanosteus	Y. longidorsalis			Also present in the Huajiying Formation	A peipiaosteid

Invertebrate fauna of the Yixian Formation

The invertebrate species listed below follow a survey by Chen and colleagues published in 2005, unless otherwise noted.^[80]

Arachnids

The arachnid species listed below follow a catalogue compiled by Dunlop, Penney and Jekel in 2010, unless otherwise noted.^[93]

Genus	Species	County	Member	Abundance	Notes	Images
?Araneus	A.? aethus				Orb-weaver spiders
	A.? beipiaoensis
	A.? liaoxiensis
	A.? reheensis
Cretaraneus	C. liaoningensis				A nephiline spider
?Gnaphosa	G.? liaoningensis				A ground spider
Jeholia[94]	J. longchengi				A buthoid scorpion
?Theridion	T.? atalus				A tangle web spider

Beetles (Coleoptera)

Genus	Species	County	Member	Abundance	Notes	Images
Anoixis	A. complanus				A desmatin click beetle[95]
Apoclion	A. antennatus				Desmatin click beetles[95]
	A. clavatus
	A. dolini
Coptoclava	C. longipoda				A beetle[96]
Desmatinus	D. cognatus				A desmatin click beetle[95]
Fortiseode	F. pervalimand				An eodromeine trachypachid beetle[97]
Glaresis	G. orthochilus				A laresid scarab beetle[98]
Hydrophilopsia	H. gracilis				Hydrophiloid water scavenger beetles[99]
	H. hydraenoides
	H. shatrovskiyi
Lasiosyne	L. integera	Huangbanjigou Village, Liaoning Province, northeastern China.[100]			A lasiosynid beetle.[100]
	L. parva	Huangbanjigou Village, Liaoning Province, northeastern China.[100]			A lasiosynid beetle.[100]
Liaoximordella	L. hongi				A mordellid beetle[101]
Mirimordella	M. gracilicruralis				A mordellid beetle[102]
Oxyporus	O. yixianus				An oxyporine rove beetle[103]
Paradesmatus	P. dilatatus				A desmati click beetle[95]
Parageotrupes	P. incanus				A Geotrupine scarab beetle[104]
Sinocupes	S. validus				A beetle[96]
Sinosperchopsis	S. silinae				A hydrophiloid water scavenger beetle[99]
Sinoxytelus	S. breviventer				Oxyteline rove beetles[105]
	S. euglypheus
	S. longisetosus

Crustaceans

Genus	Species	County	Member	Abundance	Notes	Images
Chenops[106]	C. oblongus				Notostracans
	C. yixianensis
Cricoidoscelosus	C. aethus				Junior synonym of Palaeocambarus[107]
Cypridea	C. (Cypridea) liaoningensis		Jianshangou Bed		Ostracods
	C. (C.) sihetunensis		Jianshangou Bed
	C. (C.) veridica arguta		Jingangshan Bed
	C. (C.) sp.		Jianshangou Bed
	C. (Ulwellia) beipiaoensis	Beipiao	Jianshangou Bed
Damonella	D. formosa		Jianshangou Bed		An ostracod
Darwinula	D. leguminella		Jianshangou Bed		An ostracod
Diestheria	D. jeholensis		Jianshangou Bed		Clam shrimps
	D. yixianensis		Dawangzhangzi Bed
	D.? sp.		Jianshangou Bed
Eosestheria	E. jingangshanensis		Jingangshan Bed		Clam shrimps
	E. lingyuanensis		Dawangzhangzi Bed
	E. aff. middendorfii		Jingangshan Bed
	E. ovata		Jianshangou Bed
	E. sihetunensis		Jianshangou Bed
Eosestheriopsis	E. gujialingensis		Jianshangou Bed		A clam shrimp
Jeholops[106]	J. hongi				A notostracan
Liaoningogriphus	L. quadripartitus		Jianshangou and Dawangzhangzi beds		A shrimp
Lycopterocypris	L. infantilis		Jianshangou Bed		An ostracod
Mantelliana	M. sp.		Jianshangou Bed		An ostracod
"Mongolarachne"	"M." chaoyangensis		Dawangzhangzi Beds		Junior synonym of Palaeocambarus[108]
Mongolianella	M. cf. palmosa		Jianshangou Bed		An ostracod
Palaeocambarus	P. licenti				A crayfish[109]
Rhinocyrpis	R. jurassica		Jianshangou Bed		An ostracod
Timiriasevia	T. jianshangouensis		Jianshangou Bed		An ostracod
?Yanjiestheria	Y.? beipiaoensis	Beipiao	Jianshangou Bed		A clam shrimp
Yanshania	Y. dabeigouensis		Jianshangou Bed		An ostracod

Dragonflies (Odonata)

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.

The dragonfly species listed below follow a review compiled by Zhang, Ren and Panf in 2008, unless otherwise noted.^[110]

Genus	Species	County	Member	Abundance	Notes	Images
Abrohemeroscopus	A. mengi				A dragonfly	Sinaeschnidia sp.
Aeschnidium	A. heishankowense				Reclassified as Sinaeschnidia heishankowense[111]
	A. sp.
Archaeogomphus	A. labius			Nymphs[111]	Reclassified as Yixiangomphus labius,[112] which is a junior synonym of Sinaeschnidia cancellosa[111]
Bellabrunetia	B. catherinae				A dragonfly
Chrysogomphus	C. beipiaoensis				A dragonfly
Dissurus	D. liaoyuanensis[112]			Poorly preserved nymph[111]	Reclassified as Sinaeschnidia cf. cancellosa[111]
Dracontaeschnidium	D. orientale				A dragonfly
Hebeiaeschnidia	H. fengningensis				A dragonfly
Huaxiagomphus	H. taushanensis				A dragonfly[112]
Liogomphus	L. yixianensis				A dragonfly
Mesocordulia	M. boreala				A corduliid dragonfly[101]
Palaeogomphus	P. labius				A dragonfly, reclassified as of Yixiangomphus labius,[112] which is a junior synonym of Sinaeschnidia cancellosa[111]
Parapetala	P. liaoningensis				A dragonfly
	P. yixianensis		Jianshangou Unit[113]
Protoliupanshania	P. wangi		Jianshangou Unit[113]		A liupanshaniid dragonfly
Pseudocymatophlebia	P. bisecta	Ningcheng County[114]		A well-preserved specimen.[114]	An aktassiid dragonfly
Pseudoliupanshania	P. magnanicellula		Jianshangou Unit[113]
Pseudosamarura	P. largina[96]			One specimen, nymph[111]	Reclassified as Sinaeschnidia cf. cancellosa[111]
Rudiaeschna	R. limnobia				An aeshnid dragonfly[101]
Sinaeschnidia	S. heishankowense		Jianshangou & Dawangzhangzi Beds	Adults and nymphs[111]
	S. cancellosa[111]				Junior synonym of S. heishankowense[115]
	S. sp.			Indeterminate nymph specimens[111]	Some nymph specimens have been given their own genera and species though probably belong so S. heishankowense but too poorly preserved to be certain[111]
Sinogomphus	S. taoshanensis				A dragonfly
Sinojagoria	S. imperfecta				A dragonfly
Sopholibellula	S. amoena				Dragonflies
	S. eleganti
Stylaeschnidium	S. rarum				A dragonfly
Telmaeshna	T. paradoxica	Beipiao			A dragonfly
Turanophlebia	T. liaoningensis	Beipiao[116]	Jianshangou Unit[116]		A tarsophlebiid dragonfly.
Yixiangomphus	Y. labius			Nymphs[111]	Junior synonym of Sinaeschnidia cancellosa[111]

Flies (Diptera)

Genus	Species	County	Member	Abundance	Notes	Images
Alleremonomus	A. xingi		Jianshangou Bed		A brachyceran fly
Atalosciophila	A. yanensis				A mycetophilid gnat[117]
Chironomaptera	C. gregaria				A phantom midge
Gigantoberis	G. liaoningensis				A soldier fly[118]
Lichnoplecia	L. kovalevi				A protopleciid fly[119]
Palaepangonius	P. eupterus				A horse-fly[101]
Protapiocera	P. megista				An asiloid fly[101]
Protempis	P. minuta				A brachyceran fly[101]
Protonemestrius	P. jurassicus				A tangle-veined fly[101]

Wasps (Hymenoptera)

Genus	Species	County	Member	Abundance	Notes	Images
Abropelecinus	A. annulatus	Beipiao			An iscopinine pelecinid[120]
Angaridyela	A. robusta		Jianshangou Bed		A sawfly
Azygopelecinus	A. clavatus	Beipiao			An iscopinine pelecinid[120]
Chengdeserphus	C. petidatus				A proctotrupid wasp[101]
Cretevania	C. exquisita	Beipiao			Hatchet wasps[121]
	C. pristine		Jianshangou bed
	C. vesca
Hoplitolyda	H. duolunica				The largest known sawfly ever[122]
Liaotoma	L. linearis				A xyelotomid woodwasp[101]
Manlaya	M. flexuosus				An aulacid woodwasp[101]
Procretevania	P. exquisita				Reclassified as Cretevania spp.[123]
	P. pristine
	P. vesca
Rudisiricius	R. belli				Praesiricid sawflies[124]
	R. celsus
	R. crassinodus
Scolichneumon	S. rectivenius				An ichneumonoid wasp[101]
Sinopelecinus	S. viriosus				A pelecinid[120]
Tanychora	T. exquisita		Jianshangou Bed		An ichneumon wasp

Other insects

Genus	Species	County	Member	Abundance	Notes	Images
Abrigramma	A. calophleba				A kalligrammatid lacewing[125]
Alloraphidia	A. bliquivenatica[96]				Snakeflies
	A. longistigmasa		Jianshangou Bed
Archeraphidia	A. shangyuanensis				A snakefly[96]
Baissopterus	B. liaoningensis				A snakefly[96]
Caenoephemera	C. shangyuanensis		Jianshangou Bed		A mayfly[96]
Caloraphidia	C. glossophylla				A snakefly[101]
Choromyrmeleon	C. othneius				An antlion[101]
Circulaboilus	C. aureus				A grig[126]
Cretophasmomima	C. melanogramma				A stick insect[127]	Cretophasmomima, a stick insect
?Ephemeropsis	?E. trisetalis		Jianshangou and Jingangshan beds		A mayfly. Chinese specimens probably represent species of Epicharmeropsis[128]
Epicharmeropsis	E. hexavenulosus[128]	Pingquan			Mayflies
	E. quadrivenulosus[128]	Beipiao	Jianshangou Bed
Hagiphasma	H. paradoxa		Jianshangou Bed		A stick insect
Ilerdocossus	I. beipiaoensis				Palaeontinid hemipterans[129][130]
	I. exiguus
	I. exquisitus
	I. fengningensis
	I. hui
	I. pingquanensis
Ithigramma	I. multinervia				Kalligrammatid lacewings[125]
Kalligramma	K. liaoningensis		Jianshangou Bed
Karatavoblatta	K. formosa				A cockroach[96]
Liaoaphidia	L. fornicata				A snakefly[96]
Liaonemobius	L. tanae				A sword-tail cricket[101]
Longicellochrysa	L. yixiana				A mesochrysopid lacewing[131]
Mesascalaphus	M. yangi				An owlfly[101]
Mesolygaeus	M. laiyangensis				A water bug[96]
Metabittacus	M. colosseus		Jianshangou Bed		A scorpionfly[132]
Miracossus	M. gongi				Palaeontinid hemipterans[129]
	M. ingentius
Nipponoblatta	N. acerba		Jianshangou Bed		A cockroach
Oloberotha	O. sinica				A beaded lacewing[101]
Oregramma	O. aureolosa				Kalligrammatid lacewings[125]
	O. illecebrosa
Pseudopulex	P. magnus				Stem-fleas[133][134]
	P. tanlan
Renphasma	R. sinica				A stick insect[135]
Saurophthirus	S. exquisitus				Stem-fleas[136]
	S. laevigatus
Sinochresmoda	S. magnicornia				A chresmodid water-skiing insect[137]
Sinosharaperla	S. zhaoi	Beipiao			A stonefly[138]
Sinoviparosiphum	S. lini				An aphid[101]
Sophogramma	S. lii		Jianshangou Bed		Kalligrammatid lacewings[139][125]
	S. pingquanica
Tetraphelerus	T. laetus				A moth[96]
Tyrannopsylla	T. beipiaoensis				A stem-flea[140]
Varicapitatus	V. sinuolatus	"Huangbanjigou, Chaomidian Village, Beipiao City."[141]			A hemipteran
Unnamed Vitimotauliidae	Unnamed				A caddisfly pupa, likely belonging to the Vitimotauliidae[142]

Molluscs

Genus	Species	County	Member	Abundance	Notes	Images
Amplovalvata	A. sp.		Jianshangou Bed		A gastropod
Arguniella	A. lingyuanensis		Jianshangou Bed		A bivalve, also present in the Jiufotang and Fuxin Formations
	A. yanshanensis		Jianshangou Bed		A bivalve, also present in the Jiufotang Formation
Bithynia	B. haizhouensis		Jingangshan Bed		A gastropod
Corbicula	C. anderssoni		Jianshangou Bed		Reclassified as Sphaerium anderssoni
	C. jeholense				Reclassified as Sphaerium jeholense
Gyraulus	G. sp.		Jianshangou Bed		A ramshorn snail
Probaicalia	P. vitimensis		Jianshangou Bed		A gastropod
Ptychastylus	P. harpaeformis		Jianshangou Bed		Gastropods
	P. cf. phillipi		Jianshangou Bed
Sphaerium	S. anderssoni		Jianshangou Bed		A fingernail clam, also present in the Jiufotang Formation
	S. jeholense				Junior synonym of S. anderssoni
	S. selenginense				Junior synonym of S. anderssoni
?Viviparus	V.? cf. matsumotoi		Jingangshan Bed		A snail

Flora of the Yixian Formation

Conifers

The coniferous trees and shrubs listed below were compiled in a survey by Wang and colleagues in 2006, unless otherwise noted.^[143]

Genus	Species	County	Member	Abundance	Notes	Images
Brachyphyllum					A cypress-like conifer
Cephalotaxopsis					A yew
Cunninghamia					A cypress
Elatides					A cypress
Elatocladus	E. leptophyllus				Conifers of uncertain classification
	E. manchurica[16]
Liaoningocladus	L. boii		Jingangshan Bed		A conifer of uncertain classification
Pagiophyllum					A cypress-like conifer
Pityocladus					A pine
Pityolepis	P. sp.[16]				A pine
Pityophyllum	P. cf. lindstroemi[16]				A pine
Pityostrobus					A pine
Podozamites	P. lanceolatus[16]				A conifer of uncertain classification
Schizolepis	S. jeholensis[16]
?Sequoia	S.? jeholensis[16]
Taxus					A yew
Torreya					A yew
Yanliaoia	Y. sinensis[16]

Ferns

Genus	Species	County	Member	Abundance	Notes	Images
Cladophlebis	C. spp.[16]
Coniopteris	C. sp.[16]
Onychiopsis	O. elongata[16]				Junior synonym of O. psilotoides
	O. psilotoides[16]
?Ruffordia	R.? sp.[16]

Flowering plants

Genus	Species	County	Member	Abundance	Notes	Images
Archaefructus	A. eoflora		Jianshangou Bed		A primitive, aquatic angiosperm	Archaefructus
	A. liaoningensis		Jianshangou Bed
	A. sinensisis		Dawangzhangzi Bed
Callianthus	C. dilae[144]	Liaoning			A plant with true flowers
?Davallia	D.? niehhutzuensis[16]
Erenia	E. stenoptera[144]	Liaoning			Actually a specimen of Callianthus
Leefructus	L. mirus[145]				A eudicot
Liaoxia	L. chenii[16]
?Potamogeton	P.? jeholensis[16]
Ranunculus	R. jeholensis[16]				Junior synonym of Potamogeton jeholensis
Sinocarpus	S. decussatus				A primitive eudicot

Ginkgos

Genus	Species	County	Member	Abundance	Notes	Images
Baiera	B. cf. gracilis[16]
	B. orientalis[16]
Czekanowskia	C. rigida[16]
Ginkgo	G. apodes[146]
Ginkgoites	G. sibiricus[16]
Leptostrobus	L. sp.[16]
?Nageiopsis	N.? sp.[16]
Phoenicopsis	P. cf. augustifolia[16]
Solenites	S. sp.[16]
Sphenobaiera	S. longifola[16]

Other plants

Genus	Species	County	Member	Abundance	Notes	Images
Archaeamphora	A. longicervia				Originally described as pitcher plant, later study confirmed that it is likely to be an insect galls on Liaoningocladus.	Archaeamphora
Chaoyangia	C. liangii[147]				A gnetale gymnosperm
Chaoyangicarpus	C. liangii[16]				Junior synonym of Chaoyangia liangii
Ephedra	E. sp.				A gymnosperm
Equisetum	E. sp.				A horsetail
Eragrosites	E. changii[147]				A grass-like gnetale gymnosperm
Siphonospermum	S. simplex[148]	Beipiao	Jianshangou Bed		A gnetale gymnosperm
Tyrmia	T. sp.[16]				A bennettite