The Tiaojishan Formation is a geological formation in Hebei

Hebei

' is a province of the People's Republic of China in the North China region. Its one-character abbreviation is "" , named after Ji Province, a Han Dynasty province that included what is now southern Hebei...

 and Liaoning

Liaoning

' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...

, People's Republic of China

People's Republic of China

China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...

, dating to the middle-late Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 period (Bathonian

Bathonian

In the geologic timescale the Bathonian is an age or stage of the Middle Jurassic. It lasted from approximately 167.7 Ma to around 164.7 Ma...

-Oxfordian stage). It is known for its fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 plant

Plant

Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...

s, and is made up mainly of pyroclastic rock

Pyroclastic rock

Pyroclastic rocks or pyroclastics are clastic rocks composed solely or primarily of volcanic materials. Where the volcanic material has been transported and reworked through mechanical action, such as by wind or water, these rocks are termed volcaniclastic...

 interspersed with basic volcanic and sedimentary rock

Sedimentary rock

Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....

s. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation

Haifanggou Formation

The Haifanggou Formation is a fossil-bearing rock deposit located in northeastern China, near Daohugou village of Ningcheng County. The rocks consists of coarse conglomerates, sandstone, mudstone and thin coal layers. The formation dates from the Middle Jurassic.-Arthropods:-Flora:...

 (also known as the Jiulongshan Formation) as the single "Lanqui Formation."

Age

Using Argon–argon dating, Wang and colleagues in 2005 dated part of the Tiaojishan Formation to about 160 million years ago, the beginning of the Oxfordian stage, the first stage of the Upper Jurassic epoch. In 2006, a study by Liu and colleagues used U-Pb zircon dating to conclude that the Tiaojishan Formation correlates with the Daohugou Beds

Daohugou Beds

The Daohugou Beds are a series of fossil-bearing rock deposits located in northeastern China, with the type locality around Daohugou village of Ningcheng County south of Chifeng, Inner Mongolia, but extending into southwest Liaoning. The rocks are grey, finely bedded, lacustrine, sandy mudstones...

, and the complete chronological range of this shared biota dates to between 168 and 164/152 Ma ago. A subsequent study, published in 2008, refined the age range of the formation further, finding that the lower boundary of the Tiaojishan was formed 165 Ma ago, and the upper boundary somewhere between 156-153 Ma ago.

Palaeoecology

Based on the plant life present in the Tiaojishan Formation, Wang Yongdong and colleagues determined that the climate in Liaoning during the mid Jurassic would have been subtropical

Subtropics

The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...

 to temperate, warm and humid

Humidity

Humidity is a term for the amount of water vapor in the air, and can refer to any one of several measurements of humidity. Formally, humid air is not "moist air" but a mixture of water vapor and other constituents of air, and humidity is defined in terms of the water content of this mixture,...

.

Vertebrates

Vertebrate Vertebrate Vertebrates are animals that are members of the subphylum Vertebrata . Vertebrates are the largest group of chordates, with currently about 58,000 species described. Vertebrates include the jawless fishes, bony fishes, sharks and rays, amphibians, reptiles, mammals, and birds... s of the Tiaojishan Formation
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Anchiornis Anchiornis Anchiornis is a genus of small, feathered, deinonychosaurian dinosaur. The genus Anchiornis contains the type species Anchiornis huxleyi, named in honor of Thomas Henry Huxley, an early proponent of biological evolution, and the first to propose a close evolutionary relationship between birds and...	A. huxleyi	Liaoning Liaoning ' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...		Several specimens	An archaeopterygid Archaeopterygidae The Archaeopterygidae is a group of maniraptoran dinosaurs that lived during the late Jurassic and period.-Taxonomy:The order Archaeopterygiformes was coined by Max Fürbringer in 1888 to contain the single family Archaeopterygidae and genus Archaeopteryx...  or basal Deinonychosaur.
Archaeoistiodactylus Archaeoistiodactylus Archaeoistiodactylus is a extinct genus of istiodactylid pterosaur from the Middle Jurassic of China. It is known from an incomplete skeleton with a partial skull and lower jaw recovered from rocks of the Tiaojishan Formation in western Liaoning, China. It was first named by Lü Junchang and Fucha...	A. linglongtaensis	Liaoning			An Istiodactylid Istiodactylidae Istiodactylidae is a small family of pterosaurs. This family was named in 2001 after the type genus Istiodactylus was discovered not to be a member of the genus Ornithodesmus....  pterosaur
Changchengopterus Changchengopterus Changchengopterus is a genus of non-pterodactyloid pterosaur from China . The fossil specimen of the type and only species, Changchengopterus pani, was found in the Tiaojishan Formation and described by Lü in 2009...	C. pani	Hebei Hebei ' is a province of the People's Republic of China in the North China region. Its one-character abbreviation is "" , named after Ji Province, a Han Dynasty province that included what is now southern Hebei...			A rhamphorhynchoid Rhamphorhynchoidea The Rhamphorhynchoidea forms one of the two suborders of pterosaurs and represent an evolutionary grade of primitive members of this group of flying reptiles. This suborder is paraphyletic in relation to the Pterodactyloidea, which arose from within the Rhamphorhynchoidea, not from a more distant...  pterosaur Pterosaur Pterosaurs were flying reptiles of the clade or order Pterosauria. They existed from the late Triassic to the end of the Cretaceous Period . Pterosaurs are the earliest vertebrates known to have evolved powered flight...
Darwinopterus Darwinopterus Darwinopterus is a genus of pterosaur, discovered in China and named after biologist Charles Darwin. Between 30 and 40 fossil specimens have been identified, all collected from the Tiaojishan Formation, which dates to the middle Jurassic period. The type species, D. modularis, was described in...	D. modularis	Liaoning			A rhamphorhynchoid pterosaur closely related to pterodactyloids Pterodactyloidea Pterodactyloidea forms one of the two suborders of pterosaurs , and contains the most derived members of this group of flying reptiles...
Fenghuangopterus Fenghuangopterus Fenghuangopterus is a genus of basal pterosaur that lived in northeastern China during the Middle Jurassic.The type species Fenghuangopterus lii was in 2010 described and named by Lü Junchang e.a. The generic name is derived from the Fenghuang Mountain and a Latinised Ancient Greek pteron, "wing"....	F. lii	Liaoning			A rhamphorhynchoid pterosaur
Jianchangnathus Jianchangnathus Jianchangnathus is an extinct genus of basal pterosaur from the Middle Jurassic Tiaojishan Formation of northeastern China.-Naming:Jianchangnathus was first described and named by Cheng Xin, Wang Xiaolin, Jiang Shunxing and Alexander W.A. Kellner in 2012 and the type species is Jianchangnathus...	J. robustus	Liaoning Liaoning ' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...			A rhamphorhynchoid pterosaur
Jianchangopterus Jianchangopterus Jianchangopterus is a genus of scaphognathine rhamphorhynchid pterosaur from the Middle Jurassic of western Liaoning, China. Jianchangopterus is known from a nearly complete skeleton with skull preserved. It was collected from the Tiaojishan Formation. It was first named by Lü Junchang and Bo Xue...	J. zhaoianus	Liaoning Liaoning ' is a province of the People's Republic of China, located in the northeast of the country. Its one-character abbreviation is "辽" , a name taken from the Liao River that flows through the province. "Níng" means "peace"...			A rhamphorhynchoid pterosaur
Juramaia Juramaia Juramaia is an extinct genus of very basal eutherian mammal from late Middle Jurassic deposits of western Liaoning, China. Juramaia is known from the holotype BMNH PM1343, an articulated and nearly complete skeleton including incomplete skull preserved with full dentition...	J. sinensis	Liaoning			An eutheria Eutheria Eutheria is a group of mammals consisting of placental mammals plus all extinct mammals that are more closely related to living placentals than to living marsupials . They are distinguished from noneutherians by various features of the feet, ankles, jaws and teeth... n mammal
Tianyulong Tianyulong Tianyulong is a genus of heterodontosaurid ornithischian dinosaur. The only species is T. confuciusi, whose remains were discovered in Jianchang County, Western Liaoning Province, China...	T. confuciusi	Liaoning		One specimen	A heterodontosaurid Heterodontosauridae Heterodontosauridae is a family of early ornithischian dinosaurs that were likely among the most basal members of the group...  dinosaur
Xiaotingia Xiaotingia Xiaotingia is a genus of bird-like theropod dinosaur from early Late Jurassic deposits of western Liaoning, China, containing a single species, Xiaotingia zhengi.-Discovery:...	X. zhengi	Liaoning		One specimen	An archaeopterygid Archaeopterygidae The Archaeopterygidae is a group of maniraptoran dinosaurs that lived during the late Jurassic and period.-Taxonomy:The order Archaeopterygiformes was coined by Max Fürbringer in 1888 to contain the single family Archaeopterygidae and genus Archaeopteryx...  or basal Deinonychosaur.

Invertebrates

An indeterminate aeschnoid (insect) species is known from Liaoning.

Genus	Species	Province	Stratigraphic Position	Abundance	Notes
Darwinula	D. impudica	Liaoning		An ostracod Ostracod Ostracoda is a class of the Crustacea, sometimes known as the seed shrimp because of their appearance. Some 65,000 species have been identified, grouped into several orders....
	D. magna	Liaoning		An ostracod
	D. sarytirmenensis	Liaoning		An ostracod
Shaanxiconcha	S. cliovata	Liaoning		A bivalve

Bennettitales

Cycad-like plants

Bennettitales

Bennettitales is an extinct order of seed plants that first appeared in the Triassic period and became extinct toward the end of the Cretaceous...

, the most abundant plant group in the formation. 27 species in 11 genera.

Plant Plant Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or... s of the Tiaojishan Formation.
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Anomozamites
Bennetticarpus
Cycadolepis
Jacutiella
Pteriophyllum
Ptilophyllum
Williamsonia Williamsonia Williamsonia is a fossil genus of Bennettitales, an extinct group of seed plants. The plants looked a bit like a cycad, with slender trunks up to two meters tall topped with a crown of leaves....
Williamsoniella
Zamiophyllum
Zamites

Ginkgoales

Prehistoric ginkgo trees, common, with 11 species present in 6 genera.

Plant Plant Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or... s of the Tiaojishan Formation.
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Ginkgo Ginkgo Ginkgo , also spelled gingko and known as the Maidenhair Tree, is a unique species of tree with no close living relatives...
Ixostrobus
Phoenicopsis
Sphenobaiera Sphenobaiera Sphenobaiera is a plant that lived in the Late Cretaceous period. The genus Sphenobaiera is used for plants with wedge-shaped leaves that can be distinguished from Ginkgo, Ginkgoites and Baiera by the lack of a petiole. It went extinct about...
Solenites

Pinophyta

Conifers, 5 species present in 4 genera.

Plant Plant Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or... s of the Tiaojishan Formation.
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Pityocladus
Pityophyllum
Podizamites
Schizolepis
Yuccites

Pteridophyta

Leptosporangiate ferns, represented by 17 species in 8 genera, are the second most abundant plant type in the formation.

Plant Plant Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or... s of the Tiaojishan Formation.
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Cladophlebis Cladophlebis Cladophlebis is an extinct genus of fern which grew during the late Paleozoic and Mesozoic eras . It was a common plant during that time in both the northern and southern hemispheres, and belonged to the order of plants called Filicales....  spp.					Ferns
Coniopteris					Dicksoniaceae Dicksoniaceae The Dicksoniaceae is a family of tropical, subtropical and warm temperate ferns. Most of the 5-6 genera in the family are terrestrial ferns or have very short trunks compared to tree ferns of the family Cyatheaceae. However, some of the larger species can reach several metres in height. A number of...   Tree fern Cyatheales The order Cyatheales is a taxonomic division of the fern subclass, Cyatheatae, which includes the tree ferns. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicates that the order is monophyletic. Some species in the Cyatheales have tree-like growth... s.
Dicksonia Dicksonia Dicksonia is a genus of tree ferns in the order Cyatheales. It is regarded as related to Cyathea, but is considered more primitive, dating back at least to the Jurassic and Cretaceous periods. The fossil record includes stems, pinnules, and spores....	D. changeyingziensis				Dicksoniaceae Dicksoniaceae The Dicksoniaceae is a family of tropical, subtropical and warm temperate ferns. Most of the 5-6 genera in the family are terrestrial ferns or have very short trunks compared to tree ferns of the family Cyatheaceae. However, some of the larger species can reach several metres in height. A number of...  Tree fern Cyatheales The order Cyatheales is a taxonomic division of the fern subclass, Cyatheatae, which includes the tree ferns. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicates that the order is monophyletic. Some species in the Cyatheales have tree-like growth... s.
	D. charielsa
Eboracia					Dicksoniaceae Dicksoniaceae The Dicksoniaceae is a family of tropical, subtropical and warm temperate ferns. Most of the 5-6 genera in the family are terrestrial ferns or have very short trunks compared to tree ferns of the family Cyatheaceae. However, some of the larger species can reach several metres in height. A number of...  Tree fern Cyatheales The order Cyatheales is a taxonomic division of the fern subclass, Cyatheatae, which includes the tree ferns. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicates that the order is monophyletic. Some species in the Cyatheales have tree-like growth... s.
Hausmannia	H. shebudaiensis			Uncommon.	A dipterid fern Fern A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants... .
Marattia Marattia Marattia is a small genus of primitive, large, fleshy ferns. It is the type genus of the family Marattiaceae. Formerly considered to be a much larger genus, recent genetic analysis by Murdock demonstrated its serious paraphyly, splitting off the genera Ptisana and Eupodium....	M. hoerenensis			Uncommon.	A marattiopsid Marattiopsida Class Marattiopsida is a group of ferns containing a single order, Marattiales, and family, Marattiaceae. Class Marattiopsida diverged from other ferns very early in their evolutionary history and are quite different from many plants familiar to people in temperate zones. Many of them have massive,...  fern.
Raphaelia	R. stricta				A fern.
Toadites	T. denticulata				"Flowering ferns Osmundaceae The Osmundaceae is a family of four genera and 15-25 species. It is the only fern family of the order Osmundales; an order in the class Pteridopsida or in some classifications the only order in the class Osmundopsida... ."
	T. williamsonii				"Flowering ferns Osmundaceae The Osmundaceae is a family of four genera and 15-25 species. It is the only fern family of the order Osmundales; an order in the class Pteridopsida or in some classifications the only order in the class Osmundopsida... ."

Other plants

Cycad

Cycad

Cycads are seed plants typically characterized by a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. They usually have pinnate leaves. The individual plants are either all male or all female . Cycads vary in size from having a trunk that is only a few centimeters...

s, fairly diverse, with 10 species present in 2 genera.

Plant Plant Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or... s of the Tiaojishan Formation.
Genus	Species	Location	Stratigraphic position	Abundance	Notes	Images
Ctenis					Cycad Cycad Cycads are seed plants typically characterized by a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. They usually have pinnate leaves. The individual plants are either all male or all female . Cycads vary in size from having a trunk that is only a few centimeters... ales.
Equisetum					Horsetails Equisetopsida Equisetopsida, or Sphenopsida, is a class of plants with a fossil record going back to the Devonian. They are commonly known as horsetails... .
Neocalamites					Horsetails Equisetopsida Equisetopsida, or Sphenopsida, is a class of plants with a fossil record going back to the Devonian. They are commonly known as horsetails... .
Nilssonia					Cycad Cycad Cycads are seed plants typically characterized by a stout and woody trunk with a crown of large, hard and stiff, evergreen leaves. They usually have pinnate leaves. The individual plants are either all male or all female . Cycads vary in size from having a trunk that is only a few centimeters... ales.
Hepacitities	H. shebudaiensis			Uncommon.	A bryophyte Bryophyte Bryophyte is a traditional name used to refer to all embryophytes that do not have true vascular tissue and are therefore called 'non-vascular plants'. Some bryophytes do have specialized tissues for the transport of water; however since these do not contain lignin, they are not considered to be... .
Taeniopteris sp.				Uncommon.