Dendrorhynchoides Temporal range: Middle Jurassic, | |
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Holotype of D. curvidentatus, Geological Museum of China | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Order: | † Pterosauria |
Family: | † Anurognathidae |
Genus: | † Dendrorhynchoides Ji, Ji & Padian, 1999 |
Species: | †D. curvidentatus |
Binomial name | |
†Dendrorhynchoides curvidentatus (Ji & Ji, 1998) | |
Synonyms | |
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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 first named Dendrorhynchus in 1998 by Ji Shu'an and Ji Qiang, [1] but that name proved to be preoccupied by a parasitic protozoan named in 1920 by David Keilin. It was therefore renamed in 1999. [2] The type species is Dendrorhynchoides curvidentatus. The genus name is derived from Greek dendron, "tree" and rhynkhos, "snout" in reference to it being assumed a tree-dweller and presumed a close relative of Rhamphorhynchus . The specific name means "curved-toothed" in Latin. A second species, D. mutoudengensis, was described in 2012, and moved to a new genus Luopterus in 2020. [3] [4]
The genus is based on holotype GMV2128, a fossil originally discovered around 1995 and obtained by science from illegal fossil dealers who first prepared it. It consists of a near-complete skeleton of a subadult individual and is crushed. Most elements are present, exceptions include the sternum, the tail end, sacrals and the fourth phalanx of the wing finger. This specimen was originally thought to be from the Jianshangou Bed of the Yixian Formation, dated to about 124.6 million years old. [5] However, the specimen was obtained by amateur collectors and altered to contain a piece of a dromaeosaurid tail before being studied. David Hone and Lü Junchang in 2012 considered it more likely that the holotype of D. curvidentatus was actually found in the Middle Jurassic deposits; the authors note that all other Chinese anurognathids are Jurassic in age, and that Jeholopterus was also initially thought to be a Cretaceous taxon until subsequent studies established it to be from the Jurassic. [3]
In 2010 a second specimen, of a juvenile, was announced, that proved that a more elongated tail was present after all, albeit not so long as the faked tail of the holotype: about 85% of femur length. [6] This specimen eventually was designated as the holotype of a new species, Dendrorhynchoides mutoudengensis, by Hone and Lü in 2012. [3] The specimen was originally stored in the Guilin Geological Museum and designated GLGMV 0002; later it was moved to the Jinzhou Paleontological Museum and designated JZMP-04-07-3. [3] In 2020, Hone recognized that D. mutoudengensis was as distinct from D. curvidentatus as other species of anurognathids were from each other, and elevated it to a new genus and combination Luopterus mutoudengensis , named after the late Lü. [4]
Dendrorhynchoides had a wingspan of about forty centimetres, making it one of the smallest known pterosaurs. Of the type specimen, most parts of the skull have become detached so that its shape is difficult to determine, but it was generally short and broad. Eleven teeth have been preserved scattered throughout the matrix, that are recurved with a broader base and have a length of three millimetres. The authors identified lower jaws with a preserved length of fifteen millimetres. The cervical vertebrae are short and broad. Six dorsal vertebrae have been preserved, nine ribs and six belly ribs at the left side. The tail has a preserved length of five centimetres, but part of this is accounted for by a section that might have been added to enhance the value of the fossil. The tail vertebrae at the base, the authenticity of which is certain, are short. [1]
The wings are relatively short. The humerus is robustly built but elongated with a length of 27 millimetres. The ulna is 35.5 millimetres long. The metacarpals are short with seven millimetres length for the first three, 9.3 millimetres for the fourth wing-bearing metacarpal. The first three fingers are well developed with the first having an elongated first phalanx. They bear short but sharp claws. The first phalanx of the fourth, wing, finger has a length of 44.5, the second of 35.6 millimetres. The size of the third cannot be established because of damage. A short and slender pteroid, 5.9 millimetres long, points towards the elbow. The tibia has a length of 26.7 millimetres and is about a third longer than the femur. The fibula is reduced, reaching about half-way downwards along the tibia shaft. The foot is long with the metatarsals having a length of 12.1 millimetres. The fifth toe is elongated. [1]
Because of the presumed long tail, the authors rejected a placement within the Anurognathidae and classified it instead as a long-tailed rhamphorhynchid, mainly in view of the general long bone proportions. [1] It was in 2000 identified as an anurognathid, and it was confirmed that the fossil had been doctored prior to its description. [7]
A cladistic analysis by Alexander Kellner in 2003 had the same outcome, Dendrorhynchoides being found to form an anurognathid clade with Batrachognathus , that he named Asiaticognathidae. He later admitted Asiaticognathidae was an inappropriate name, as the clade's definition did not include an Asiaticognathus, and proposed Batrachognathinae as a replacement name. [8] An analysis by Lü and Qiang Ji in 2006 resolved the relations even further, finding Dendrorhynchoides to be the sister taxon of clade formed by Batrachognathus and Jeholopterus. [9] In 2021, a phylogenetic analysis conducted by Xuefang Wei and colleagues recovered Dendrorhynchoides within the subfamily Anurognathinae, which is unlike the former studies where it was recovered as closely related to Batrachognathus. Dendrorhynchoides was found to have been the basalmost member of this subfamily in Wei and colleagues' study. [10] Below is a cladogram representing their phylogenetic analysis:
The describers postulated a tree-dwelling lifestyle for Dendrorhynchoides as an insectivore. With very large eye sockets and a rounded head, Dendrorhynchoides would have had great eyesight. They could use these features to quickly spot insects and be able to follow their motion while following behind them. With their smaller wingspan and skeletal body, along with very flexible joints, these traits gave them great movability to catch the small insects and prey they were chasing. Its large eyes that were forward facing and the small claws on its appendages had researchers assuming that the species would match closely to tree bark or dark night colors to blend in with its surroundings and ambush insects for nocturnal hunting, just like what is seem with modern-day nightjars or bats. [2]
Jeholopterus was a small anurognathid pterosaur known from the Middle to Late Jurassic Daohugou Beds of the Tiaojishan Formation of Inner Mongolia, China, and possibly the Early Cretaceous Sinuiju Formation of North Korea.
Anurognathus is an extinct genus of small pterosaur from the Late Jurassic Altmühltal Formation of Germany.
Batrachognathus is an extinct genus of anurognathid pterosaur from the Late Jurassic Karabastau Formation of the central Asian republic of Kazakhstan. The genus was named in 1948 by the Russian paleontologist Anatoly Nicolaevich Ryabinin. The type species is Batrachognathus volans. The genus name is derived from Greek batrakhos, "frog" and gnathos, "jaw", in reference to the short wide head. The specific epithet means "flying" in Latin.
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; Jeholopterus, from the Middle to Late Jurassic of China; Dendrorhynchoides, from the Middle Jurassic of China; Batrachognathus, from the Late Jurassic of Kazakhstan; and Vesperopterylus, from the Early Cretaceous of China. Bennett (2007) suggested that the holotype of Mesadactylus, BYU 2024, a synsacrum, belonged to an anurognathid, though this affinity has been questioned by other authors. Mesadactylus is from the Late Jurassic Morrison Formation of the United States. Indeterminate anurognathid remains have also been reported from the Middle Jurassic Bakhar Svita of Mongolia and the Early Cretaceous of North Korea.
Eosipterus is an extinct genus of ctenochasmatid pterosaur from the Early Cretaceous period of Liaoning, China. Fossil remains of Eosipterus dated back to the Aptian stage of the Early Cretaceous, 125 million years ago.
Eoazhdarcho is a genus of azhdarchoid pterodactyloid pterosaur named in 2005 by Chinese paleontologists Lü Junchang and Ji Qiang. The type and only known species is Eoazhdarcho liaoxiensis. The fossil was found in the Aptian-age Lower Cretaceous Jiufotang Formation of Chaoyang, Liaoning, China.
Feilongus is an extinct genus of ctenochasmatid pterodactyloid pterosaur from the Barremian–Aptian-age Lower Cretaceous Yixian Formation of Beipiao, Liaoning, China.
Pterorhynchus is an extinct genus of pterosaur from the mid-Jurassic aged Daohugou Formation of Inner Mongolia, China.
Elanodactylus is a genus of ctenochasmatid pterodactyloid pterosaur from the Early Cretaceous period of what is now the Yixian Formation of Liaoning, China.
The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period. It is known for its exceptionally preserved fossils, including those of plants, insects and vertebrates. It is made up mainly of pyroclastic rock interspersed with basic volcanic and sedimentary rocks. Previously, the Tiaojishan Formation was grouped together with the underlying Haifanggou Formation as a single "Lanqi Formation." The Tiaojishan Formation forms a key part of the Yanliao Biota assemblage, alongside the Haifanggou Formation.
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, 160.89–160.25 Ma ago. The type species, D. modularis, was described in February 2010. D. modularis was the first known pterosaur to display features of both long-tailed (rhamphorhynchoid) and short-tailed (pterodactyloid) pterosaurs, and was described as a transitional fossil between the two groups. Two additional species, D. linglongtaensis and D. robustodens, were described from the same fossil beds in December 2010 and June 2011, respectively.
Zhenyuanopterus is a genus of boreopterid pterosaur which is known from Lower Cretaceous Yixian Formation of Liaoning, China. It contains one species, Zhenyuanopterus longirostris, which was first described and named by Lü Junchang.
Moganopterus is an extinct genus of ctenochasmatid pterosaur from the Early Cretaceous of western Liaoning Province, China.
This timeline of pterosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of pterosaurs, the famed flying reptiles of the Mesozoic era. Although pterosaurs went extinct millions of years before humans evolved, humans have coexisted with pterosaur fossils for millennia. Before the development of paleontology as a formal science, these remains would have been interpreted through a mythological lens. Myths about thunderbirds told by the Native Americans of the modern Western United States may have been influenced by observations of Pteranodon fossils. These thunderbirds were said to have warred with water monsters, which agrees well with the co-occurrence of Pteranodon and the ancient marine reptiles of the seaway over which it flew.
Forfexopterus is a genus of ctenochasmatid pterosaur from the Early Cretaceous Jiufotang Formation in China. It contains a single species, F. jeholensis, named from a mostly complete skeleton by Shunxing Jiang and colleagues in 2016. A second specimen, consisting of a wing, was described in 2020. While the first specimen is larger, it shows signs of being less mature than the second specimen, indicating that the developmental trajectories of Forfexopterus were variable. Like other ctenochasmatids, Forfexopterus had a long, low skull filled with many slender teeth; unlike other members of the group, however, it did not have a spatula-shaped snout tip or crests, and its teeth were more curved. A single characteristic distinguishes Forfexopterus from all other members of the wider group Archaeopterodactyloidea: of the four phalanx bones in its wing finger, the first was shorter than the second but longer than the third.
Vesperopterylus is a genus of anurognathid pterosaur from the Early Cretaceous Jiufotang Formation of China, the geologically youngest member of its group. Notably, Vesperopterylus appears to have a reversed first toe, which would have been suited for gripping; it was likely arboreal, climbing or clinging to tree branches with curved, sharp claws. It also has a relatively short tail, in contrast with its tailless (Jeholopterus) and long-tailed (Dendrorhynchoides) relatives. It was first described and named by Lü Junchang et al. While the original spelling of the name was Versperopterylus, this was a typo, and was emended by the authors in accordance with the International Code of Zoological Nomenclature.
Luopterus is an extinct genus of anurognathid pterosaur containing only the holotype species L. mutoudengensis that is known from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebei Province, China. It was originally named as a species of Dendrorhynchoides in 2012 but it was moved to the genus Luopterus in 2020. Luopterus was originally thought to be from the Early Cretaceous, with a wingspan that is about 40 centimeters (16 in), making it one of the smallest known pterosaurs.
Sinomacrops is a genus of extinct anurognathid pterosaur from the Middle to Late Jurassic periods of what is now the Daohugou Beds of the Tiaojishan Formation in Mutoudeng, Qinglong County of the Hebei province. The remains of Sinomacrops date back to around 164 to 158 million years ago. The type and only known species is Sinomacrops bondei.
Cascocauda is an extinct genus of anurognathid pterosaur from the Late–Middle Jurassic Tiaojishan Formation of Hebei Province, China. The genus contains a single species, C. rong, known from a complete skeleton belonging to a juvenile individual preserved with extensive soft-tissues, including wing membranes and a dense covering of pycnofibres. Some of these pycnofibres appear to be branched, resembling the feathers of maniraptoran theropod dinosaurs, and suggesting that pterosaur pycnofibres may be closely related to feathers in dinosaurs.