''Liaodactylus'' is a genus of filter-feeding
ctenochasmatid
Ctenochasmatidae is a group of pterosaurs within the suborder Pterodactyloidea. They are characterized by their distinctive teeth, which are thought to have been used for filter-feeding. Ctenochasmatids lived from the Late Jurassic to the Early ...
pterosaur
Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the Order (biology), order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cre ...
from the
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...
of
China. The genus contains one species, ''L. primus'', described by Zhou ''et al.'' in 2017. As an adaptation to filter-feeding, ''Liaodactylus'' had approximately 150 long, comb-like teeth packed closely together. It is both the earliest known ctenochasmatid and the first filter-feeding pterosaur from the Jurassic
Tiaojishan Formation
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of ...
. Later and more specialized ctenochasmatids differ from ''Liaodactylus'' in having longer snouts, smaller openings (or fenestrae) in the skull, and more teeth. Within the Ctenochasmatidae, ''Liaodactylus'' was most closely related to the European ''
Ctenochasma
''Ctenochasma'' (meaning "comb jaw") is a genus of Late Jurassic ctenochasmatid pterosaur belonging to the suborder Pterodactyloidea. Three species are currently recognized: ''C. roemeri'' (named after Friedrich Adolph Roemer), ''C. taqueti'', a ...
''.
Discovery and naming

There is one specimen of ''Liaodactylus'' known, namely the
holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of seve ...
PMOL-AP00031, which is stored at the Palaeontological Museum of Liaoning. It consists of a complete skull and lower jaws, along with the first two
cervical vertebrae
In tetrapods, cervical vertebrae (singular: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In ...
. It originates from outcrops located about west of the village of Daxishan, in
Jianchang County
Jianchang () is a county of Huludao City in the southwest of Liaoning province, China. It is the largest division of Huludao, with an area of , and population of 600,000, located in mountainous terrain west of that city, serviced by China Natio ...
,
Liaoning,
China. These outcrops belong to the
Late Jurassic
The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987.
In European lithostratigraphy, the ...
Tiaojishan Formation
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of ...
, which has been dated to range from 161.8 ± 0.4 to 159.5 ± 0.6 million years ago (
Oxfordian) based on
argon-argon dating.
''Liaodactylus'' was described in 2017 by Zhou ''et al.'' The genus name combines ''Liao'', a shortened prefix form of "Liaoning", with Greek ''dactylos'' ("finger"), a standard pterosaurian suffix. Meanwhile, the specific name ''primus'', from Latin, refers to the early age of ''Liaodactylus'' relative to other
ctenochasmatid
Ctenochasmatidae is a group of pterosaurs within the suborder Pterodactyloidea. They are characterized by their distinctive teeth, which are thought to have been used for filter-feeding. Ctenochasmatids lived from the Late Jurassic to the Early ...
s.
Description
Snout, jaw and teeth
The head of ''Liaodactylus'' is slender and long, with a skull length of and a jaw length of .
Out of this, the snout is 49.1% of total skull length, and the
nasoantorbital fenestra (the fusion of the nostril and the
antorbital fenestra
An antorbital fenestra (plural: fenestrae) is an opening in the skull that is in front of the eye sockets. This skull character is largely associated with archosauriforms, first appearing during the Triassic Period. Among extant archosaurs, birds ...
, seen in all members of the
Monofenestrata
Monofenestrata is an unranked group of pterosaurs that includes the family Wukongopteridae and the suborder Pterodactyloidea.
The clade Monofenestrata was in 2009/2010 defined as the group consisting of ''Pterodactylus'' and all species sharin ...
) is 31% of skull length. In more
derived
Derive may refer to:
* Derive (computer algebra system), a commercial system made by Texas Instruments
* ''Dérive'' (magazine), an Austrian science magazine on urbanism
*Dérive, a psychogeographical concept
See also
*
*Derivation (disambiguatio ...
ctenochasmatids, the nasoantorbital fenestra is much smaller relative to the skull, being only 10-12% of skull length in ''
Pterodaustro
''Pterodaustro'' is a genus of ctenochasmatid pterodactyloid pterosaur from South America. Its fossil remains dated back to the Early Cretaceous period, about 105 million years ago. The most distinctive characteristic that separates ''Pterodaus ...
''; the snout is also longer, being over 85% of skull length in ''Pterodaustro''.
Also shorter than other ctenochasmatids is the
dentary symphysis
In human anatomy, the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge, indicating the mandibular symphysis (Latin: ''symphysis menti'') or line of junction where the two lateral halves ...
, the fused portion of the lower jaw, which is only 30.5% of jaw length. Morphologically, the sides of the snout are parallel (unlike the spoon-tipped snouts of ''
Gnathosaurus
''Gnathosaurus'' (meaning "jawed lizard") is a genus of ctenochasmatid pterosaur containing two species: ''G. subulatus'', named in 1833 from the Solnhofen Limestone of Germany, and ''G. macrurus'', known from the Purbeck Limestone of the UK. I ...
''), most of the
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bon ...
is composed mainly of the dentary, and the well-developed retroarticular process is formed by the
angular bone The angular is a large bone in the lower jaw (mandible) of amphibians and reptiles (birds included), which is connected to all other lower jaw bones: the dentary (which is the entire lower jaw in mammals), the splenial, the suprangular, and the ...
like in other ctenochasmatids.
There are many long, needle-like, outward-projecting, tightly packed, equally-spaced teeth in the jaws of ''Liaodactylus'', totalling to 152 teeth across both jaws. This is more than ''Gnathosaurus'' (128–136), about the same as ''
Gegepterus
''Gegepterus'' is a genus of ctenochasmatid pterosaur from the Early Cretaceous period of what is now the Yixian Formation of Liaoning, China. Only one species is known, ''G. changi''.
History and etymology
The genus was named in 2007 by Wang ...
'' (150),
but much less than ''
Ctenochasma
''Ctenochasma'' (meaning "comb jaw") is a genus of Late Jurassic ctenochasmatid pterosaur belonging to the suborder Pterodactyloidea. Three species are currently recognized: ''C. roemeri'' (named after Friedrich Adolph Roemer), ''C. taqueti'', a ...
'' (200-552)
and ''Pterodaustro'' (almost a thousand).
The teeth become shorter towards the back of the jaws, eventually becoming short, peg-like structures at the back of the tooth row; the back of the tooth row corresponding to the front 1/3 of the nasoantorbital fenestra, which is unusual among ctenochasmatids (where the teeth usually stop entirely before the fenestra). The first tooth at the front of each jaw is also somewhat shortened, being only half the length of the second. Collectively, the teeth, which would have interlocked when the jaw was closed, form a comb-like complex that would have been used for filter-feeding.
Side of the skull and palate
Among ctenochasmatids, the
jugal bone
The jugal is a skull bone found in most reptiles, amphibians and birds. In mammals, the jugal is often called the malar or zygomatic. It is connected to the quadratojugal and maxilla, as well as other bones, which may vary by species.
Anat ...
of ''Liaodactylus'' is quite narrow, especially below the large eye socket. It splits into three branches: the very long and tapering anterior process, which forms the back two-thirds of the bottom border of the nasoantorbital fenestra; the vertical orbital process; and the angled temporal process, which is very long compared to the orbital process. The bone is bent slightly such that the margin of the jaw below the eye socket is curved. At the back, the temporal process of the jugal has fused rather extensively with the neighboring
quadratojugal bone The quadratojugal is a skull bone present in many vertebrates, including some living reptiles and amphibians.
Anatomy and function
In animals with a quadratojugal bone, it is typically found connected to the jugal (cheek) bone from the front an ...
. Further back on the skull, the
quadrate bone
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids (reptiles, birds), and early synapsids.
In most tetrapods, the quadrate bone connects to the quadratojugal and squamosal bones in the skull, and forms uppe ...
articulates with the
squamosal bone The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone.
In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...
above and the lower jaw below; the long shaft at the rear of the quadrate is very strongly angled, forming an angle of 160° with the jaw margin, like other ctenochasmatids. The jaw joint is directly underneath the eye socket.
At the back of the
maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The ...
, the
palate
The palate () is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity.
A similar structure is found in crocodilians, but in most other tetrapods, the oral and nasal cavities are not truly s ...
form a wide shelf which is deeply notched at the back, forming in part the suborbital fenestra. Small spikes along the midline of the suborbital fenestra represent the
palatine bone
In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the throat. Together with the maxillae, they comprise the hard palate. (''Palate'' is derived from the Latin ...
s, which contact the maxilla. The ectopterygoid bones are three-pronged; the lateral processes close off the back of the suborbital fenestra, the anterior processes join the process of the palatal shelf, and the posterior process overlaps the
pterygoid bone
The pterygoid is a paired bone forming part of the palate of many vertebrates, behind the palatine bone
In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the ...
and forms part of the pterygo-ectopterygoid fenestra, which is separated from the suborbital fenestra by a bar of the pterygoid; the same bar is seen in ''Gnathosaurus'', albeit much shorter.
As for the pterygoid itself, it was expanded along the midline and projected backwards to connect to the
basisphenoid bone and quadrate.
Braincase and vertebrae
The top of the
braincase
In human anatomy, the neurocranium, also known as the braincase, brainpan, or brain-pan is the upper and back part of the skull, which forms a protective case around the brain. In the human skull, the neurocranium includes the calvaria or skul ...
consists of the strongly-fused
frontal bone
The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...
and
parietal bone
The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named ...
, which curve sharply downwards near the back so as to produce a rounded back of the skull. At the back of the skull, the basisphenoid is short, wide, and platelike, and has a wide U-shaped notch at the front end. At either side of the notch is a stout basisphenoid process, which contacts the
pterygoid bone
The pterygoid is a paired bone forming part of the palate of many vertebrates, behind the palatine bone
In anatomy, the palatine bones () are two irregular bones of the facial skeleton in many animal species, located above the uvula in the ...
and quadrate. Meanwhile, at the back, the basisphenoid becomes narrower and is overlapped by the
basioccipital bone
The basilar part of the occipital bone (also basioccipital) extends forward and upward from the foramen magnum, and presents in front an area more or less quadrilateral in outline.
In the young skull this area is rough and uneven, and is joined t ...
. On the basioccipital, the
occipital condyle
The occipital condyles are undersurface protuberances of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra.
The condyles are oval or reniform (kidney-shaped) in shape, and their anteri ...
, which connects to the vertebrae, is spherical; consequently, the hole for the spinal cord, the
foramen magnum
The foramen magnum ( la, great hole) is a large, oval-shaped opening in the occipital bone of the skull. It is one of the several oval or circular openings (foramina) in the base of the skull. The spinal cord, an extension of the medulla oblonga ...
, is hidden when the vertebrae are articulated. There is a roughened ridge extending along the midline of the basioccipital, forward from the occipital condyle.
As for the
cervical vertebrae
In tetrapods, cervical vertebrae (singular: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In ...
themselves, the
atlas
An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth.
Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...
and
axis
An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to:
Mathematics
* Axis of rotation: see rotation around a fixed axis
* Axis (mathematics), a designator for a Cartesian-coordinat ...
are fused, albeit with a visible
suture. In front of the atlas is a small, rudimentary proatlas, which is symmetrical, platelike, and has a projection at the front. Corresponding to the spherical occipital condyle is the cup-like joint of the atlas. The atlas had a prominent
neural spine
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
, but the neural spine on the axis is not exposed. At the back of the axis, on the
neural arch
The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...
, is the
postzygapophysis
The articular processes or zygapophyses (Greek ζυγον = "yoke" (because it links two vertebrae) + απο = "away" + φυσις = "process") of a vertebra are projections of the vertebra that serve the purpose of fitting with an adjacent vertebr ...
, which would have connected to the next cervical vertebra.
Classification
Zhou ''et al.'' assigned ''Liaodactylus'' to the
Ctenochasmatidae
Ctenochasmatidae is a group of pterosaurs within the suborder Pterodactyloidea. They are characterized by their distinctive teeth, which are thought to have been used for filter-feeding. Ctenochasmatids lived from the Late Jurassic to the Early C ...
in 2017 based on a
phylogenetic analysis
In biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that pro ...
. It shares with other ctenochasmatids the relative proportions of its skull height at the
squamosal bone The squamosal is a skull bone found in most reptiles, amphibians, and birds. In fishes, it is also called the pterotic bone.
In most tetrapods, the squamosal and quadratojugal bones form the cheek series of the skull. The bone forms an ancestral co ...
, its skull height at the jaw joint, and the length of the snout at the level of the
nasoantorbital fenestra; additionally, in terms of morphological characters, it shares a retroarticular process that is pointed backwards and downwards. Within the Ctenochasmatidae, ''Liaodactylus'' was found to be closest to ''
Ctenochasma
''Ctenochasma'' (meaning "comb jaw") is a genus of Late Jurassic ctenochasmatid pterosaur belonging to the suborder Pterodactyloidea. Three species are currently recognized: ''C. roemeri'' (named after Friedrich Adolph Roemer), ''C. taqueti'', a ...
'', with which it shares the ratio of jaw-to-skull length and the teeth being angled out to the sides. The phylogenetic tree recovered by the analysis is reproduced below.
Paleoecology
''Liaodactylus'' is known from the
Tiaojishan Formation
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian- Oxfordian stages). It is known for its exceptionally preserved fossils, including those of ...
, which along with the older
Haifanggou Formation
The Haifanggou Formation (), also known as the Jiulongshan Formation (), is a fossil-bearing rock deposit located near Daohugou () village of Ningcheng County, in Inner Mongolia, northeastern China.
The formation consists of coarse conglomerate ...
form the
Yanliao Biota
The Yanliao Biota is the name given to an assembly of fossils preserved in northeastern China from the Middle to Late Jurassic.Xu, X., Zhou, Z., Sullivan, C. and Wang, Y., 2017. The Yanliao Biota: a trove of exceptionally preserved Middle-Late Jur ...
, a diverse assemblage of well-preserved Jurassic animals containing at least 40 species. A number of other pterosaurs have been found from the Yanliao Biota, including the
rhamphorhynchids ''
Jianchangnathus robustus'' and ''
Qinglongopterus guoi
''Qinglongopterus'' is a genus of rhamphorhynchid pterosaur from the Middle/Upper Jurassic of Mutoudeng, Qinglong County, Hebei Province, China. ''Qinglongopterus'' is known from only one specimen; D3080/3081, a nearly complete skeleton coll ...
''; the
anurognathid
Anurognathidae is a family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Five genera are known: ''Anurognathus'', from the Late Jurassic of Germany; ''Jeholop ...
s ''
Dendrorhynchoides mutoudengensis
''Dendrorhynchoides'' was a genus of anurognathid pterosaur containing only the holotype species ''D. curvidentatus'' that is known from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebei Province, China.
The genus was fi ...
'' and ''
Jeholopterus ninchengensis''; the
darwinoptera
Monofenestrata is an unranked group of pterosaurs that includes the family Wukongopteridae and the suborder Pterodactyloidea.
The clade Monofenestrata was in 2009/2010 defined as the group consisting of ''Pterodactylus'' and all species sharing ...
n ''
Pterorhynchus wellnhoferi''; and the
wukongopterids ''
Darwinopterus modularis'', ''
Wukongopterus lii'', and possibly ''
Archaeoistiodactylus linglongtaensis
''Archaeoistiodactylus'' is an extinct genus of wukongopterid pterosaur from the Middle Jurassic of China.
Discovery and naming
''Archaeoistiodactylus'' is known from an incomplete skeleton with a partial skull and lower jaws. Catalogued as h ...
'',
among many others.
''Liaodactylus'' represents the first Yanliao filter-feeding pterosaur.
Dinosaurs from the Yanliao Biota include the
scansoriopterygid
Scansoriopterygidae (meaning "climbing wings") is an extinct family of climbing and gliding maniraptoran dinosaurs. Scansoriopterygids are known from five well-preserved fossils, representing four species, unearthed in the Tiaojishan Formation fo ...
s ''
Epidendrosaurus ninchengensis'', ''
Epidexipteryx hui
''Epidexipteryx'' is a genus of small paravian dinosaurs, known from one fossil specimen in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing. ''Epidexipteryx'' represents the earliest known example of or ...
'', and ''
Yi qi''; the
paravian
Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the aviala ...
s ''
Anchiornis huxleyi
''Anchiornis'' is a genus of small, four-winged paravian dinosaurs, with only one known species, the type species ''Anchiornis huxleyi'', named for its similarity to modern birds. The Latin name ''Anchiornis'' derives from a Greek word meaning "n ...
'', ''
Pedopenna daohugouensis
''Pedopenna'' (meaning "foot feather") is a genus of small, feathered, maniraptoran dinosaur from the Daohugou Beds in China. It is possibly older than ''Archaeopteryx'', though the age of the Daohugou Beds where it was found is debated. A m ...
'', and ''
Xiaotingia zhengi
''Xiaotingia'' is a genus of anchiornithid theropod dinosaur from Middle Jurassic or early Late Jurassic deposits of western Liaoning, China, containing a single species, ''Xiaotingia zhengi''.
Discovery
''Xiaotingia'' is known from the holot ...
''.
Non-archosaurs are also present in the Yanliao Biota.
Mammaliaforms
Mammaliaformes ("mammalian forms") is a clade that contains the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts. It is defined as the clade originating from the most recent comm ...
include ''
Liaotherium gracile'', ''
Manchurodon simplicidens'', ''
Pseudotribos robustus
''Pseudotribos'' ("false chewing") is an extinct genus of mammal that lived in Northern China during the Middle Jurassic some , possibly more closely related to monotremes than to theria ( placental and marsupial mammals), although other studi ...
'', ''
Volaticotherium antiquum'', ''
Castorocauda lutrasimilis'', ''
Docofossor brachydactylus
''Docofossor'' is an extinct mammaliaform (a docodont) from the Jurassic period. Its remains have been recovered in China from 160 million years old rocks. It appears to have been the earliest-known subterranean mammaliaform, with adaptations rem ...
'', ''
Arboroharamiya jenkinsi
''Arboroharamiya'' ("tree thief" from Latin arbor, "tree" + Arabic الحرامية (al ḥarāmiyah), "thief, '' Haramiya''") is an extinct genus of early mammal (or possibly a non-mammalian mammaliaform) from the Middle Jurassic Tiaojishan Form ...
'', ''
Megaconus mammaliaformis'', ''
Xianshou linglong
''Xianshou'' is a genus of glidingQing-Jin Meng; David M. Grossnickle; Di Liu; Yu-Guang Zhang; April I. Neander; Qiang Ji; Zhe-Xi Luo (2017). "New gliding mammaliaforms from the Jurassic". Nature. in press. . haramiyidan synapsid known from the ...
'' and ''X. songae'', ''
Shenshou lui
''Shenshou'' is a genus of haramiyidan dating from the Oxfordian stage of the Late Jurassic, approximately 160 million years ago. Fossils were recovered from the Tiaojishan Formation in the Liaoning province of China.
Etymology
The generic ...
'', and ''
Juramaia sinensis
''Juramaia'' is an extinct genus of very basal eutherian mammal known from the Late Jurassic ( Oxfordian stage) deposits of western Liaoning, China. It is a small shrew-like mammal with a body length of approximately 70–100 mm, making ...
''.
Additionally, there are lizards, including ''
"Yabeinosaurus" youngi'';
an undescribed
crocodylomorph
Crocodylomorpha is a group of pseudosuchian archosaurs that includes the crocodilians and their extinct relatives. They were the only members of Pseudosuchia to survive the end-Triassic extinction.
During Mesozoic and early Cenozoic times, cro ...
; salamanders, including ''
Chunerpeton tianyiensis
''Chunerpeton tianyiensis'' is an extinct species of salamander from the Late Jurassic Daohugou Beds in Ningcheng County, Nei Mongol (Inner Mongolia), China. It is the only species classified under the genus ''Chunerpeton''. It was a small ...
'', ''
Jeholotriton paradoxus'', ''
Liaoxitriton daohugouensis'', and ''
Pangerpeton sinensis'';
and fish, including ''
Liaosteus hongi'' and a member of the
Ptycholepidae.
In terms of environment, the Tiaojishan Formation represents a forested woodland with conifers, cycads, and ferns. Plant species present include the
horsetail
''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds.
''Equisetum'' is a " living fossil", the only living genus of the entire subclass ...
s ''
Neocalamites carcinoides'', ''N. narthosi'', and ''
Equisetum sp.''; the
tree fern
The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae (scaly tre ...
s ''
Coniopteris hymenophyloides'' and ''C. margaretae''; the
cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or f ...
''
Zamites gigas''; the enigmatic
gymnosperm
The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, '' Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμν ...
s ''
Czekanowskia ketova'', ''C. ridiga'', and ''
Phoenicopsis speciosa''; the
ginkgo
''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus withi ...
''
Sphenobaiera kazachstanica''; the
cypress
Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the la ...
''
Protaxodioxylon jianchangense''; and the indeterminate
conifer
Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ex ...
''
Xenoxylon peidense''.
Collectively, they indicate a cool, temperate, wet, and seasonal climate with a mean temperature below 15 °C.
This is consistent with a trend of global cooling around this time,
but contrasts with the warm, dry climate of the earlier Haifanggou.
References
{{Portal bar, Paleontology, China
Ctenochasmatoids
Late Jurassic pterosaurs of Asia
Fossil taxa described in 2017
Oxfordian life
Paleontology in Liaoning