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Discovery of a pterodactylid pterosaur from the Yixian Formation of western Liaoning, China

  • Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences

Abstract and Figures

A well-preserved pterosaur with nearly complete skull is described from the Lower Cretaceous Yixian Formation at Sihetun in western Liaoning. It is characterized by a low and long crestless skull, slender and pointed teeth, long metacarpal, nearly equal length of metatarsals I–III and short pedal digit V. It is referred to a new genus and species of the family Pterodactylidae:Haopterus gracilis gen. et sp. nov. This is the first pterosaur with a nearly complete skull from the Jehol Biota; it also represents the first non-controversial fossil record of Pterodactylidae in Asia.Haopterus is more derived thanPterodactylus from the Late Jurassic Solnhofen in Germany. This discovery extends the distribution of the family Pterodactylidae from Europe and Africa to Asia and its latest occurrence from the Late Jurassic to the Early Cretaceous. The discovery ofHaopterus gracilis provides further evidence for the study of the origin and radiation of the Jehol Biota; it also sheds new light on the evolution and distribution of pterosaurs in the late Mesozoic.
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1112 Chinese Science Bulletin Vol. 46 No. 13 July 2001
Discovery of a pterodactylid
pterosaur from the Yixian
Formation of western
Liaoning, China
WANG Xiaolin1,2 & LÜ Junchang1,3
1. Institute of Vertebrate Paleontology and Paleoanthropology, Chinese
Academy of Sciences, Beijing 100044, China;
2. College of Earth Sciences and Resources, China University of Geo-
sciences, Beijing 100083, China;
3. Department of Geological Sciences, Southern Methodist University,
Dallas, TX 75275, USA
-897,.9 A well-preserved pterosaur with nearly com-
plete skull is described from the Lower Cretaceous Yixian
Formation at Sihetun in western Liaoning. It is character-
ized by a low and long crestless skull, slender and pointed
teeth, long metacarpal, nearly equal length of metatarsals
and short pedal digit . It is referred to a new genus
and species of the family Pterodactylidae: Haopterus gracilis
gen. et sp. nov. This is the first pterosaur with a nearly com-
plete skull from the Jehol Biota; it also represents the first
non-controversial fossil record of Pterodactylidae in Asia.
Haopterus is more derived than Pterodactylus from the Late
Jurassic Solnhofen in Germany. This discovery extends the
distribution of the family Pterodactylidae from Europe and
Africa to Asia and its latest occurrence from the Late Juras-
sic to the Early Cretaceous. The discovery of Haopterus
gracilis provides further evidence for the study of the origin
and radiation of the Jehol Biota; it also sheds new light on
the evolution and distribution of pterosaurs in the late
Keywords: western Liaoning, Early Cretaceous, Yixian Formation,
Western Liaoning Province is most notable for the
excellent preservation of the famous Jehol Biota. Recently,
a lot of important vertebrate fossils[1,2] including the
primitive bird Confuciusornis[3] and various feathered di-
nosaurs[46] have been discovered from the lacustrine de-
posits of the third member of the Early Cretaceous low
Yixian Formation at Sihetun, Beipiao, Chaoyang[1,2].
These fossils form a unique vertebrae assemblage from
the terrestrial lake deposits in the Mesozoic and represent
an important biological radiation event in the Early Cre-
taceous[2]; it provides important evidence for the study of
the origin and early radiation of major vertebrate groups
such as birds.
A total of more than 10 individual pterosaurs have
recently been discovered from the lower Yixian Formation
in Sihetun areas, western Liaoning Province. Most of
them were referred to Eosipterus[7] and Dendrorhyn-
choides[8], respectively; others remain unnamed. None of
these specimens preserved the skull, therefore their phy-
logenetic position remain controversial[7,8]. A new speci-
men of pterosaur was collected during the field season of
the IVPP (Institute of Vertebrate Paleontology and Pa-
leoanthropology) in 1998, it contains a nearly complete
skull and most of the postcranial bones. It is the first in-
disputable remains of the family Pterodactylidae from
Asia, and extends the distribution from Europe and Africa
to Asia and its latest occurrence from the Late Jurassic to
the Early Cretaceous. The discovery of Haopterus gracilis
gen. et sp. nov. provides further evidence for the study of
the evolution and distribution of pterosaurs in the late
1 Systematic paleontology
Order Pterosauria Kaup, 1834
Suborder Pterodactyloidea Plieninger, 1901
Family Pterodactylidae Bonaparte, 1838
Genus Haopterus gen. nov.
Species Haopterus gracilis gen. et sp. nov.
Diagnosis. Small to medium-sized pterosaur. Maxi-
mum wingspan 1.35 m. Skull length 145 mm. Skull low
and long; rostrum pointed; crest absent at the rear of the
skull; nasopreorbital opening elongate and elliptical. 12
pointed and posteriorly inclined teeth in both upper and
lower jaws. Teeth of the premaxilla (first 3 teeth of the
upper jaw) slender. Fourth and more posterior teeth con-
stricted at the base. Teeth extend posteriorly toward the
middle of the nasopreorbital opening, about 66.4% of the
lower jaw equipped with teeth. Forelimb robust. Humerus
short, robust and straight, delto-pectoral crest expanded
and semicircular. Wing metacarpal long and about 1.3
times that of the humerus. Phalanges of the wing
digit longer than wing metacarpal. Ulna and phalanx I of
wing digit 1.1 and 1.4 times that of the wing metacarpal,
respectively. Metatarsals reduced; Metatarsals of
nearly equal length; metatarsals and reduced and
short; Length of metatarsal about 18.7% that of wing
metacarpal. Sternum fan-shaped; its length equals its
width; keel well-developed.
Holotype. A nearly complete skeleton that con-
tains a complete skull and pectoral girdle, forelimbs, ster-
num, cervical, dorsal, metatarsals and digits. Institute of
Vertebrate Paleontology and Paleoanthropology specimen
number: IVPP V11726 (figs. 1 and 2).
Etymology. The genus name is dedicated to Prof.
Yichun Hao, a distinguished Chinese paleontologist who
has contributed significantly to the study of the Jehol Bi-
ota; the species name reflects both the beautiful preserva-
tion and the tiny metatarsals of the holotype.
Horizon and locality. Locality 1 at Sihetun, Shan-
gyuan, Beipiao, western Liaoning; Jianshangou Bed of the
lower Yixian Formation[1,2], late Valanginian (age of
Jurassic/Cretaceous boundary is 135 Ma) or Barremian
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Chinese Science Bulletin Vol. 46 No. 13 July 2001 1113
Fig. 1. Haopterus gracilis gen. et sp. nov. (IVPP V11726, holotype).
(Jurassic/Cretaceous boundary is 144 Ma) of the Early
Description. A nearly complete subadult individ-
ual with skull but lacks pelvis, femur, tibia, fibula, caudal
and sacral. Both ends of long bones are less well ossified.
Measurements of major skeletal elements are listed in
table 1.
Skull. The skull is lateroventrally preserved. It is
low and 145 mm long. The rostrum is pointed. The crest is
absent at the rear of the skull. There are 12 teeth in both
the upper and lower jaws. The 5 front teeth are slender,
more posterior teeth are constricted at the base. Teeth
number is less than that of pterodactylus[9].
The premaxilla and the maxilla are fused; no suture
is recognizable between these two bones. Teeth extend
from the anterior end to the middle of the nasopreorbital
opening. Teeth are pointed and posteriorly inclined. Teeth
of the premaxilla (first 3 teeth of the upper jaw) represent
tiny replaceable teeth. The nasopreorbital opening is
elongate and elliptical and 40mm long, which is 27.6%
that of the skull length. The nasal is small and nearly ver-
tical near the dorso-posterior margin of the nasopreorbital
opening. The nasal overlaps the adlacrimal. The frontal is
missing. Most of the bones of the posterior skull are
crushed and undistinguishable, but the left squamosal and
jugal are recognizable.
Table 1 Measurements of skeletal elements of the holotype
(IVPP V11726) of Haopterus gracilis gen. et sp. nov.
Name Left/mm Right/mm
Humerus 70 60+
Ulna 101 102
Scapula 30
Coracoid 34
Wing metacarpal 89 91
First phalanx of wing digit 141 138
Second phalanx of wing digit 119 119
Third phalanx of wing digit 95 96
Fourth phalanx of wing digit 44+ 45+
Pteroid 34
Metatarsal 17 17
Metatarsal 17 17
Metatarsal 17 17
Metatarsal 13 13
Metatarsal 5
Sternum 45 (length) 46 (width)
Skull 145
Lower jaw 128 85 (with dentition)
The posterior part of the lower jaw is toothless. The
lower jaw with dentation is 85 mm long, which is 66.4%
of the total length of the lower jaw. The teeth of the lower
jaw are similar to those of the upper jaw in size, shape and
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1114 Chinese Science Bulletin Vol. 46 No. 13 July 2001
Fig. 2. The outline of the skeleton of Haopterus gracilis gen. et sp. nov. (IVPP V 11726, holotype). a, Angular; al, adlacrimal; c, carpal;
ce, cervical vertebrae; cor, coracoid; cris, cristospine; d, dentary; do, dorsal vertebrae; dp, delto-pectoral crest; ga, gastralia; hu, humerus;
is, ischium; j, jugal; m, maxilla; mc , metacarpals ; mt , metatarsals ; n, nasal; npo, nasopreorbital open-
ing, pm, premaxilla; po, postorbital; pt, pteroid; q, quadrate; r, radius; ri, rib; sa, surangular; sc, scapula; sq, squamosal; ster, sternum; t,
tarsal; u, ulna; wph , wing phalanges ; , fingers .
pattern; the first tooth is slightly inclined anterolaterally.
The angular and the surangular are tightly attached to the
dentary. The quadrate is long, plate-shaped and slightly
curved dorsally. The hyoid is slender and 52 mm long.
Vertebral column.
Cervical and dorsal vertebrae
are preserved, but sacrals and caudals are missing. Cervi-
cal vertebrae are crushed together with the posterior skull
bones. The anterior 8 dorsal vertebrae are preserved, their
combined length is 52 mm. The dorsal vertebra is pro-
coelous. The anterior dorsals are short and become pro-
gressively elongate distally. Some incomplete ribs and
isolated gastralia are preserved.
Pectoral girdle and forelimb. The left pectoral
girdle is ventrally preserved while the right side is dor-
sally preserved. The left coracoid is completely preserved;
it is rod-like, straight and thick-walled; the proximal end
is robust with a procoracoid process in articulation with
the scapula; distally it is not expanded, and has an obvious
articulation with the sternum; ventrally it has a longitudi-
nal groove which becomes wider distally. The left scapula
is complete; it is thin, plate-shaped; its length is about
88.2% that of the scapula; distally the scapula is expanded
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Chinese Science Bulletin Vol. 46 No. 13 July 2001 1115
and robust.
Both the left and right humeri lack the proximal end.
The humerus is straight; the delto-pectoral crest is semi-
circular and expanded laterally; the left humerus is in ar-
ticulation with the coracoid and scapula.
The right radius, ulna and the left ulna are well pre-
served and in articulation with the humerus and the car-
pals. The radius and the ulna are straight, thin-walled and
expanded at both ends. The radius is slender and slightly
longer than the ulna.
The carpals are small; left carpals are crushed to-
gether with the posterior skull bones and cervical verte-
brae. The left pteroid is well preserved; it is slender and
straight but does not taper toward the distal end.
The metacarpals are not completely preserved.
Metacarpals are nearly of equal length, they are
slightly longer than the humerus but are shorter than the
ulna. Metacarpals are slender; they are parallel
and tightly attached to metacarpal . Metacarpal
(wing metacarpal) is robust; it is proximally expanded and
in close contact with the carpals; distally it is in articula-
tion with the wing digit. The wing metacarpal is 1.3 times
the length of the humerus. The ulna is 1.1 times as long as
the wing metacarpal.
The digits are completely preserved. Digits
are completely preserved on the right side and digits
are preserved on the left side. Digits are
slender, the distal phalanges are short and the unguals are
sharp. Digit IV is long and preserved all 4 phalanges; they
are all robust, straight and thin-walled; they are expanded
at both ends, with the proximal end wider than the distal
end. The fourth phalanx of the wing digit tapers distally
although its distal extremity is missing. The length of the
phalanges of the wing digit decreases toward to the distal
end; the first three phalanges are longer than wing meta-
carpal; the first phalanx is 1.4 times as long as the wing
metacarpal. The phalangeal format of the hand is 2-3-4-4.
To compare the length of the major elements of the
forelimb, we list them in progressively decreasing order as
follows: first phalanx of the wing digit, second phalanx of
the wing digit, ulna, third phalanx of the wing digit, wing
metacarpal, humerus, fourth phalanx of the wing digit.
The sternum is fan-shaped. The keel is well devel-
oped and extends anteriorly to one third of the sternal
plate; it is about half as long as the sternum. The sternum
is thin; its length equals the width. Ventrally it is most
similar to that of Gallodactylus and Nesodactylus[9].
Pelvic girdle and hindlimb. Only the posterior
margin of the left ischium is preserved, it is semicircular
and thin, with the dorsal margin thickened. It is most
similar to the ischium of Pterodactylus[9].
Most of the hindlimb elements are missing. Tarsals,
metatarsals and a few pedal digits are preserved. Proximal
tarsals are large and the distal tarsals are small and fused.
Compared to the forelimbs, the metatarsals and digits are
extremely reduced and small. Metatarsals are of
equal length; is slightly shorter; is shorter than
. The length of metatarsal is only about 18.7% that
of the wing metacarpal. Digits and also preserved
the unguals. Digit has only one short phalanx and
preserved its impression. The pedal phalangeal format is
2 Comparisons and discussions
Among the two suborders of Pterosauria the Rham-
phorhynchoidea occurred from the Late Triassic to the
Late Jurassic and is characterized by the presence of a
long tail while the short-tailed Pterodactyloidea has been
known from the Late Jurassic to the Late Cretaceous.
Haopterus gracilis gen. et sp. nov. is characterized by a
low and long crestless skull, a unified nasopreorbital
opening, short teeth in both the upper and lower jaws,
short pedal digit and long wing metacarpal. These
characters show that Haopterus should be referred to the
Pterodactyloidea. Based on the character of the nearly
complete skull including the dentition, it can be compared
with the known members of different families of Ptero-
Pterodactyloidea comprises 15 families[10], among
them are the Late Cretaceous toothless Pteranodontidae,
Nyctosauridae, Azhdarchidae from North America and the
Tapejaridae from the Early Cretaceous of Brazil and An-
hangueridae, Criorhynchidae, Germanodactylidae and
Dsungeripteridae that possess both teeth in the jaws and a
crest on the skull[10 12]. Among the families that possess
teeth but lack a skull crest are Ctenochasmatidae from the
Late Jurassic of Germany, France and the Early Creta-
ceous of China[13] and Pterodaustridae form the Early
Cretaceous of Argentina and Chile; these groups possess
several hundred dense teeth in both the upper and lower
jaws. Some members of the family Ctenochasmatidae also
have a skull crest[9,10], which can be easily distinguished
from Haopterus. Cearadactylidae from the Early Creta-
ceous Santana Formation in Brazil comprises large-sized
pterosaurs that have a small skull with especially long and
robust teeth[10]. Ornithodesmidae from the Early Creta-
ceous (Wealden) of England has short and robust teeth
and a duck-bill-shaped rostrum[10]. Both of these families
are distinguishable from Haopterus. Besides, the family
Ornithocheridae, which is widely distributed in the Early
Cretaceous to the Late Cretaceous deposits in Europe,
Africa, South America and Australia, comprise large-sized
pterosaurs which have a low and slender skull, and the
teeth are short, pointed and densely distributed. A few
members of this family also possess a skull crest[10].
Haopterus is a small to medium sized pterosaur. Its
skull characters are most similar to those of the Late Ju-
rassic Pterodactylidae and Gallodactylidae from
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1116 Chinese Science Bulletin Vol. 46 No. 13 July 2001
Europe[9,10]; the later two families are distinguishable from
each other by both the teeth morphology and the postcra-
nial characters. Gallodactylidae has slender teeth, which
are only distributed in the anterior jaws and a short crest at
the rear of the skull. The dentition of Haopterus as well as
other characters is most similar to that of Pterodactylidae,
therefore Haopterus is referred to the family Pterodac-
Pterodactylidae is composed of one genus (Ptero-
dactylus) and 13 species[10]. Haopterus can be clearly dis-
tinguished from Pterodactylus by the following character:
fewer teeth, fusion between the premaxilla and the maxilla,
fusion of the tarsals, sternum with a well-developed carina,
well-developed pectoral girdle, more expanded delto-
pectoral crest of the humerus, well-developed procoracoid,
more developed wing digit, the first three phalanges of the
wing digit longer than the wing metacarpal. All these
characteristics are related to more powerful flying capa-
bility. In addition, Haopterus also has very reduced meta-
tarsals, Metatarsals are of equal length and less
than one fifth of the length of the wing metacarpal while
Pterodactylus has more developed hindlimbs. Compared
with Pterodactylus, Haopterus is probably more adapted
to flight than terrestrial life.
Pterosaurs were believed to be more adapted to bi-
pedal locomotion based on its forelimb and pectoral girdle
structure[14]; however, further work on large pterosaur
Anhanguera from the Early Cretaceous Santana Forma-
tion of Brazil indicates that they probably lived a quadru-
pedal life[15]. The extremely reduced hindlimb of Haop-
terus indicates that it cannot be bipedal; small to medium-
sized pterosaurs were probably quadrupedal most of the
Haopterus has a large skull and a pointed rostrum;
the front teeth are sharp and slender, suggesting a pis-
civorous feeding habit. It probably has strong flight capa-
bility and the body was suspended by the hindlimb in
resting position.
Eosipterus from the same horizon as Haopterus did
not preserve the skull; the limb bones were not completely
preserved. It can be easily distinguished from the latter by
the following characters: the ulna is as long as the first
phalanx of the wing digit, but is 1.3 times as long as the
wing metacarpal, metatarsals are relatively long, metatar-
sal I is about 57.5% of the length of the wing metacarpal.
Eosipterus was recently referred to the Pterodactyli-
dae[16,17]. Since it lacks the skull character we believe that
more material is needed to discuss its phylogenetic posi-
tion. The discovery of Haopterus represents the first un-
controversial pterodactylid pterosaur in Asia, it also ex-
tends the distribution of this family to the Early Creta-
Dendrorhynchoides is another pterosaur that has
been described from the lower Yixian Formation at the
same locality as Haopterus in western Liaoning. It pre-
served a very crushed skull containing no diagnostic
characters. It was referred to Rhamphorhynchoidea[8].
Although it still preserved a few primitive characteristics
such as the short metacarpals it also has many more de-
rived characteristics such as the long wing digit, etc. Its
phylogenetic position remains a mystery[2].
Haopterus was collected from the Jianshangou Bed
of the lower Yixian Formation, it is the lower fos-
sil-bearing bed of the Jehol Biota. Associated with this
pterosaur are important fossil vertebrates[1,2,18] including
Lycopterus, Psittacosaurus, several feathered thero-
pods[46], and Confuciusornis[3]. 40Ar/39Ar dating of the
single crystal sanidine from the horizon resulted in an age
of (124.6 0.3) Ma (124.6 0.2) Ma[19], therefore it
should be referred to the late Valanginian (age of Juras-
sic/Cretaceous boundary is 136 Ma) or the middle Barre-
mian (Jurassic/Cretaceous boundary 144 Ma)[2]. The ver-
tebrate assemblage also suggests an Early Cretaceous
Among the pterosaurs known from the Jianshangou
Bed of the lower Yixian Formation in Sihetun areas,
western Liaoning, Dendrorhynchoides was collected at the
Zhangjiagou locality, which is the lowest fossil-bearing
horizon of the lower Yixian Formation, Haopterus was
collected from 18(6) of the excavation section[1,2] of local-
ity 1 of Sihetun which is about 5.5m higher than Den-
drorhynchoides, Eosipterus was collected from the Tuan-
shanzi locality, the horizon of which is higher than the
Sihetun locality[2].
The pterosaur assemblage in the lower Yixian For-
mation is more advanced than that of the Late Jurassic
(Tithonian) in Solnhofen, Germany. It, however, bears a
lot resemblance to that of the Early Cretaceous (Ap-
tian-Albian) Santana Formation in Brazil[11]. We believe
that the Valanginian or Barremian age derived from iso-
tope dating[2,19] is consistent with the pterosaur assem-
blages as well as other vertebrate assemblages of the
lower Yixian Formation.
Pterodactyloid pterosaurs occurred abundantly in the
Early Cretaceous deposits in northern China, Mongolia
and former Russia[13,21,22]. Most notable among them are
Huanhepterus of the Huanhe Formation from the Ordos
Basin[13] and Dsungeripterus of the Tugulu Group from
the Junggar Basin of Xinjiang[21]and Tsagantsab Forma-
tion from Mongolia[22]. These Early Cretaceous pterosaurs
belong to Pterodactyloidea.
In summary, members of the Pterodactylidae are
previously known only in the Late Jurassic (Kim-
meridgian-Tithonian) in Europe and Africa[10]. Haopterus
represents the first occurrence of an non-controversial
pterodactylidae in the terrestrial Early Cretaceous deposit
in Asia. Therefore this family had existed longer than pre-
viously known. The discovery of Haopterus also provides
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Chinese Science Bulletin Vol. 46 No. 13 July 2001 1117
new evidence for the study of the global stratigraphic cor-
relations of the Late Jurassic and Early Cretaceous depos-
Acknowledgements We thank members of the Liaoxi Expedition
Team of the IVPP for various supports. Profs. Meemann Chang, Zhou
Zhonghe (IVPP) and Dr. Miao Desui (Natural History Museum, Univer-
sity of Kansas) read the manuscript and provided valuable suggestions.
Zhou Zhonghe improved the English version of the manuscript. We also
thank Li Yutong for preparing the specimen, Zhang Jie the photos and
Huang Jinlin the illustration. This work was supported by the Chinese
Academy of Sciences (Grant Nos. KZ951-B1-410 and KZCX3-J-03), the
Major Basic Research Project of the Ministry of Science and Technology
of China (Grant No. G2000077700), the National Natural Science
Foundation of China (Grant Nos. 49832002 and J9930095) and K. C.
Wong Education Foundation, Hong Kong.
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(Received February 13, 2001)
... The sternum of Haopterus was described by Wang and Lü (2001) as being fan-shaped, although it might be better considered as semi-circular ( Figure 11A). It has a long cristospine, with a strong midline keel that extends onto the anterior half of the sternal plate. ...
... It has a long cristospine, with a strong midline keel that extends onto the anterior half of the sternal plate. The sternal plate itself is about as wide as long and is thin (Wang and Lü, 2001). ...
... It is 4.5 mm long, slightly less than half the length of metatarsal IV. This proportion is comparable with that in Haopterus (38.5%, Wang and Lü 2001) and Zhenyuanopterus (54.5%, Lü 2010). ...
... Furthermore, the penultimate phalanges are slender and longer than the proximal phalanges as in SDUST-V1006, but shorter than the associated metatarsals ( Figure 4). A similar condition seems to be present in the basal ornithocheiroid Haopterus (Wang and Lü 2001), which is closely related to the Istiodactylidae (Kellner et al. 2019). However, its pedal digits are poorly preserved and could not provide more detailed information for a further comparison. ...
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As the lowest horizon of the Early Cretaceous Jehol Biota, the Huajiying Formation of the northern Hebei Province, China is rich with avians and feathered dinosaurs, but lacks pterosaur record. Here the first pterosaur fossil is reported from the Huajiying Formation. The new pterosaur specimen is characterized by an unusual pedal configuration of a short and spread metatarsus with elongate digits, showing a close resemblance to the dentulous Ornithocheiroidea. The pedal configuration is diverse in pterosaurs, and is often associated with ecological adaptations. In contrast to the general pattern of the elongate metatarsus and short digits, the elongate digits of the dentulous ornithocheiroids (e.g. boreopterids and istiodactylids) might offset the shortened metatarsus to enlarge the pedal surface for paddling, representing a new strategy in adaptation to the aquatic environment.
... If we can suppose the average size of the manus and pes can represent the actual size, Ornithocheiroids (including istiodactylids, ornithocheirids, pteranodontids, and nyctosaurids) can be excluded from consideration as trackmakers because the manus length (represented by manus digit III) is comparable to, or exceeds, pes length in ornithocheirids (e.g., Zhenyuanopterus 62 ) and pteranodontids (Pteranodon 63 ). This unusual proportion seems to apply to istiodactylids, based on Haopterus 64 and Mimodactylus 24 , where the metatarsus is preserved but not the pedal digits. Nyctosaurids lack manus digits I-III (e.g. ...
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Here we describe a new pterosaur footprint assemblage from the Hwasun Seoyuri tracksite in the Upper Cretaceous Jangdong Formation of the Neungju Basin in Korea. The assemblage consists of many randomly oriented prints in remarkably high densities but represents a single ichnotaxon, Pteraichnus. Individuals exhibit a large but continuous size range, some of which, with a wingspan estimated at 0.5 m, are among the smallest pterosaurs yet reported from the Upper Cretaceous, adding to other recent finds which contradict the idea that large and giant forms entirely dominated this interval. Unusual features of the tracks, including relatively long, slender pedal digit impressions, do not match the pes of any known Cretaceous pterosaur, suggesting that the trackmakers are as yet unknown from the body fossil record. The Hwasun pterosaur footprints appear to record gregarious behavior at the exact location by individuals of different ages, hinting at the possibility that pterosaurs gathered in mixed-age groups.
... Eine Einschränkung besteht darin, dass sich diese Verlängerung bei sehr jungen Individuen noch nicht realisiert hat (Wellnhofer 1968(Wellnhofer , 1987Wellnhofer 1970, Abb. 5, 6, 8, 9;Vidovic & Martill 2017). Aufgrund der Größe von JME-ETT-04391 ist dieser Umstand ausgeschlossen (Bennett 1995;Hone et al. 2020 (Wang & Lu 2001;Frey et al. 2011). Gerade die Eupterodactyloidea können verbreiterte Halswirbel aufweisen, was in isolierter Betrachtung der Erscheinung von JME-ETT-04391 nahekommt (siehe Dsungaripterus: Lu et al. 2009 , Fig. 6). ...
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Die Spur einer Spur-ein möglicher erster Flugsaurier aus Ettling Trace of a trace-a putative first pterosaur from the Ettling locality Archaeopteryx, 37: 75-83; Eichstätt 2021 Zusammenfassung Aus den Plattenkalken von Ettling sind im Vergleich zu anderen Fundstellen des oberjurassischen Solnhofen-Archipels bislang nur wenige Reptilreste und keine von Flugsauriern geborgen worden. Ein neu identifiziertes Fossil von mäßiger Erhaltung wird mit Vorbehalt als zwei assoziierte, aber dislozierte Halswirbel interpre-tiert. Ihre Form und ursprünglich filigrane Knochen-struktur legen einen Flugsaurier nahe. Sollte dies zu-treffen, liegt wahrscheinlich ein überdurchschnittlich großer Rhamphorhynchide vor, zudem einer der größ-ten Juraflugsaurier weltweit. Abstract Compared to other localities of the Upper Jurassic Sol-nhofen Archipelago, the Plattenkalk from Ettling has so far produced only a few reptilian remains, none of them from pterosaurs. A newly identified, badly preserved fossil is tentatively interpreted as two associated but dislocated cervical vertebrae. Their shape and originally delicate bone structure suggest a pterosaur. If true, an outstandingly large rhamphorhynchid would be present, moreover one of the biggest Jurassic ptero-saurs on a global scale. Abb. 1: Neu identifiziertes Fossil aus der Grabung Ettling, JME-ETT-04391, zwei wahrscheinlich in Beziehung stehende, stark ge-löste und daher mutmaßliche Halswirbel eines Pterosauriers. Fig. 1: Newly identified fossil from the Ettling excavation, JME-ETT-04391, two likely associated, but heavily dissolved and therefore only supposed cervical vertebrae of a pterosaur.
... In Q. lawsoni and most pterosaurs, the scapula forms an elongate process (Fig. 28), unlike the stout and constricted shape found in the Lanceodontia (Andres, 2021). The lanceodontians have a distinct kink at this constriction, whereas the pteranodontians and Haopterus gracilis Wang and Lü, 2001, have essentially straight shafts, and the azhdarchoids and non-eupterodactyloids have a gentle curvature. In Q. lawsoni, the medial margin of the scapula ramus has a relatively gentle curve, whereas the lateral margin has more of an angular flexure due to a large supraglenoid tubercle (small inflation of dorsal margin of Cai and Wei, 1994, large tubercle for the origin of a muscle probably M. triceps brachii of Bennett, 2001a, or triceps tubercle of McGowen et al., 2002. ...
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Quetzalcoatlus is the largest flying organism ever known and one of the most familiar pterosaurs to the public. Despite a half century of interest, it remains very incompletely described. This shortfall is addressed here through a full morphological description of Quetzalcoatlus and the other pterosaur material of Big Bend National Park, Texas. The first reported material was described and named Quetzalcoatlus northropi by Douglas Lawson in 1975, but in two separate publications. A ruling by the International Commission of Zoological Nomenclature was required for the name to be made available. Review of the pterosaur fauna of the Park recovers three valid species of azhdarchid pterosaurs in the latest Cretaceous Period Javelina and Black Peaks formations. The size and occurrence of these species are correlated with depositional environment. The holotype of the giant Quetzalcoatlus northropi and six other giant specimens referred to it occur in stream-channel deposits, including the youngest reported pterosaur. The vast majority of specimens (200+) are from large pterosaurs found in the abandoned channel-lake deposits at Pterodactyl Ridge; they form a diagnosable natural group erected as the new species Quetzalcoatlus lawsoni. A moderate-sized partial skull and cervical series also found in the abandoned channel-lake deposits at Pterodactyl Ridge, but lower in the section, is distinct from both species and is erected as Wellnhopterus brevirostris, gen. et sp. nov. Overbank flood-plain facies preserve another eleven specimens of extreme size variation, including small azhdarchids. The Big Bend pterosaur fauna provides the greatest known sample of azhdarchid pterosaurs and three-dimensional pterosaur morphology.
... Similarly, Feilongus youngi (Wang et al., 2005) bears a greater number of alveoli, possessing 20 pairs in the rostralmost 100 mm of the mandible (compared with five pairs in KKF494). Zhenyuanopterus longirostris (Lu, 2010) and the pterodactyloid Haopterus gracilis (Wang and Lü, 2001) also differ from KKF494 in that the orientation of their rostral-most pairs of alveoli are almost perpendicular to the occlusal surface of the dentary, contrasting with the dorsolateral orientation displayed by the corresponding pairs on KKF494. The rostralmost part of the mandible of Liaoningopterus gui, a crested anhanguerian from the Jiufotang Formation (Wang and Zhou, 2003), is more robust in comparison with that of KKF494. ...
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Pterosaur fossils from Australia are exceptionally rare. Since the discovery of the continent’s first pterosaur some 40 years ago, fewer than 20 specimens have been described. The Lower Cretaceous (upper Albian) Toolebuc Formation of North West Queensland is the most productive horizon for Australian pterosaurs. Herein, we describe a new species of pterosaur, Thapunngaka shawi gen. et sp. nov., from the Toolebuc Formation, near Richmond, North West Queensland. The specimen (KKF494) comprises the rostral portion of a crested mandible and represents the largest pterosaur yet described from Australia. The new species presents features that indicate an affinity with Anhangueridae, which is consistent with their reported cosmopolitan distribution during this period. Thapunngaka shawi can be distinguished from other anhanguerids through the possession of a mandible with a smooth dorsal surface medially and uniquely sized alveoli that are positioned laterally along the jaw. Phylogenetic analysis reveals a close relationship among all Australian anhanguerids and points to an endemic Australian radiation within Anhangueridae. Thapunngaka shawi has the largest mandibular crest of any anhanguerian worldwide, and provides further evidence for the existence of an increasingly diverse range of large crested pterosaurs in the Australian part of eastern Gondwana during the Cretaceous.
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The Istiodactylidae is a group of pterodactyloids characterised by large nasoantorbital fenestrae and labiolingually compressed teeth, with several records reported from the Early Cretaceous of northeastern China and western Europe. Here we report a new istiodactylid, Lingyuanopterus camposi gen. et sp. nov. from the Jiufotang Formation of Lingyuan, Liaoning, northeastern China. The holotype is represented by a near-complete skull, mandible and atlas-axis complex. It is distinguished from other istiodactylids by several characters, including two autapomorphies: short triangular tooth crowns with sharp mesial and distal carinae limited to the distal teeth, mandibular symphysis occupying approximately a quarter the mandible length. We also report the presence of helical jaw joints in istiodactylids, and provide a revised diagnosis of the clade Istiodactylidae, which includes five genera: Istiodactylus , Liaoxipterus , Nurhachius , Luchibang and Lingyuanopterus . Four pellets containing fish fragments were observed and are tentatively interpreted as bromalites of Lingyuanopterus . Although members of this clade possess similar skull morphologies, istiodactylids vary in terms of their dentition, with at least three forms from the Jiufotang Formation alone. This may represent different feeding strategies, and also indicate a similarity between the pterosaur assemblages of northeastern China and Britain during the Early Cretaceous.
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A new and articulated specimen of a pterosaur wing including upper arm, forearm, parts of the carpus and metacarpus, and a wing phalanx from Maastrichtian phosphatic deposits of Morocco are assigned to Tethydraco cf. regalis Longrich et al., 2018. The specimen comes from the village of Ouled Abdoun, close to the Oued Zem basin and its phosphatic mines (Morocco). The fossil is part of the collection of the Université Hassan II of Casablanca (ID Number FSAC CP 251). In the first part, the thesis presents a synthetic introduction about the morphology, anatomy, physiology and evolution of pterosaurs in order to offer a comprehensive framework on this fascinating group of extinct flying tetrapods. The main goal of this work is the taxonomic identification of the specimen, principally by morphological and morphometric/statistic analysis, based on the comparison with the most similar pterosaurs of the same epoch. Aspect of the humerus morphology and dimensional ratios of the wing elements suggest that T. cf. regalis is an azhdarchid rather than pteranodontid, as originally proposed. A high abundance of azhdarchid remains in the open marine setting of the Moroccan phosphates casts doubt on suggestions that Azhdarchidae were largely terrestrial pterosaurs.
An analysis of the structure and kinematics of the forelimbs and hindlimbs of pterosaurs, and functional analogy with recent and fossil vertebrates, supports a reappraisal of the locomotory abilities of pterosaurs. A hypothesis of structural, aerodynamic, and evolutionary differences distinguishing vertebrate gliders from fliers is proposed; pterosaurs fit all the criteria of fliers but none pertaining to gliders. The kinematics of the reconstructed pterosaur flight stroke reveal a down-and-forward component found also in birds and bats; structural features of the shoulder girdle and sternum unique to pterosaurs may be explained in light of this motion. The recovery stroke of flight was accomplished, in birdlike fashion, by a functional reversal of the action of the M. supracoracoideus by the pronounced enlargement of the acrocoracoid process, which acted as a pulley. The wing membrane was supported and controlled through a system of stiffened, intercalated fibers, which were oriented like the main structural elements in the wings of birds and bats. The hindlimbs of pterosaurs were independent of the wing membrane, and articulated like those of other advanced archosaurs and birds, not like those of bats. The gait was parasagittal and the stance digitigrade. Because of limitations on the motion of the forelimb at the shoulder, pterosaurs could not have walked quadrupedally. However, bipedal locomotion appears to have been normal and quite sufficient in all pterosaurs. There is nothing batlike about pterosaur anatomy; on the other hand, pterosaurs bear close structural resemblances to birds and dinosaurs, to which they are most closely related phylogenetically.
A new incomplete pterosaurian skeleton, Eosipterus yangi gen. et sp. nov. , collected from western Liaoning is briefly described. It is the first occurrence of the pterosaurs from the famous Jehol Fauna in Northeast China; thus it is of great value to biostratigraphy and biogeography. According to the nature of the new pterosaur and other fossils in the same beds, this flying animal is supposed to have lived along the coast of a large freshwater lake which developed during the Late Jurassic and Early Cretaceous. The new genus and species should be assigned to the suborder Pterodactyloidea. Its main characters are given as follows: Medium-sized pterodactyloid pterosaur with a total width about 1.2m across two ends of distal wing-fingers. Tail short. Gastralia narrow and weak. Forelimb strong; radius and ulna 1.3 times as long as wing-metacarpal. Wing-finger joints extensible transversely. Femur slightly straight, occupying the 2/3 length of tibia. Radius, the first wing-finger as long as tibia. Metatarsal I-IV long and narrow; phalange V of hindlimb degenerated and small.