Changyuraptor

Changyuraptor is a genus of "four-winged", predatory dinosaurs. It is known from a single fossil specimen representing the species Changyuraptor yangi, which was discovered from Early Cretaceous (125 million year old) deposits in Liaoning Province, China.[1] C. yangi belongs to the group of dromaeosaurid theropod dinosaurs called the Microraptoria.[1]

At the time of its discovery, C. yangi was the largest four-winged dinosaur known[1][2] and among the largest Mesozoic flying paravians, volant true birds seldom approaching its size.[3]

Changyuraptor
Temporal range: Early Cretaceous, 125 Ma
Changyuraptor
Life restoration of C. yangi
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Dromaeosauridae
Clade: Microraptoria
Genus: Changyuraptor
Han et al., 2014
Type species
Changyuraptor yangi
Han et al., 2014

Description

Analysis of the fossil at the University of Cape Town, South Africa reveals that the specimen was a fully grown adult, approximately 1.2 metres (3.9 ft) long and estimated to weigh 4 kilograms (8.8 lb), roughly the size of a turkey. These dimensions make Changyuraptor the largest four-winged microraptorine known, exceeding previously known specimens in size by at least 60%.[4][5][6]

Like other microraptorines, Changyuraptor had feathers all over its body, including forelimbs and hindlimbs, which gives the appearance of having two pairs of wings. The presence of long feathers on all four limbs also suggests that these dinosaurs could fly.[4]

The dinosaur's tail is long and feathered, with end feathers up to 29.27 centimetres (11.52 in) long, equalling approximately 30% of the length of the animal's skeleton.[1] This length exceeds the previous record length of 7 inches (18 cm) for feathers from non-avian dinosaurs.[4] The elongated tail feathers are thought to have helped provide softer and safer landings.[4] They could have controlled pitch, a feature useful for a heavier animal, that would have attained a faster gliding speed.[1]

While elongated feathers on the hindlimbs were present in many early birds, such as Archaeopteryx, the morphology of microraptorines suggests a different aerodynamic model from that of modern birds, which have characteristically bald legs and exhibit stable flight using two wings only.[6]

Changyuraptor is thought to have existed alongside a variety of predatory and herbivorous dinosaurs of the Jehol Biota, including Yutyrannus, in moist temperate forest, primarily vegetated by ginkgos and conifers, with hot, dry summers and frosty winters.[4]

Discovery

The fossil, holotype HG B016, was discovered by farmers near Xijianchang in the Early Cretaceous fossil deposits, the Yixian Formation, of the Jehol Biota, located in the Liaoning province of China. From 2012 it was studied by an international team of scientists led by Dr. Luis Chiappe, Director of the Dinosaur Institute at the Natural History Museum of Los Angeles County.[4][7] The holotype consists of a rather complete skeleton with skull, compressed on a plate and counterplate. It shows extensive remains of the integument in the form of pennaceous feathers.[1] In 2014, the specimen was described as the new genus and species Changyuraptor yangi. The generic name of the dinosaur combines the Chinese words for "long feather", 長羽 (cháng yǔ), with Latin raptor ("robber", "seizer"). The specific name honours researcher Professor Yang Yandong.[8]

The Jehol Biota are found in the richest fossil beds for feathered dinosaurs in the world which have yielded notable species such as Yutyrannus huali, a feathered tyrannosauroid with a length of 27 to 30 feet (8.2 to 9.1 m) and the largest feathered dinosaur known to date.[4][9]

In 2003 Microraptor, a raven-sized dinosaur, approximately 1 kilogram (2.2 lb) in weight, was the first of the microraptorines to be discovered. It shared with species such as Anchiornis and Xiaotingia large feathered limbs and elongated bony tails with long tail feathers. These features caused experts to hypothesize that miniaturisation was an essential evolutionary step to enable flight. Changyuraptor's larger size and weight contradicts that hypothesis.[5][6] Changyuraptor is also the second four-winged dinosaur to be discovered after Microraptor.[1] Changyuraptor and other microraptorines add to the evidence that dinosaurs had evolved a host of morphological features and behaviours such as feathers, hollow bones, nesting behaviour, and possibly flight, before they evolved in birds.[5][6][8]

See also

References

  1. ^ a b c d e f g Gang Han; Luis M. Chiappe; Shu-An Ji; Michael Habib; Alan H. Turner; Anusuya Chinsamy; Xueling Liu & Lizhuo Han (15 July 2014). "A new raptorial dinosaur with exceptionally long feathering provides insights into dromaeosaurid flight performance". Nature Communications. 5: 4382. doi:10.1038/ncomms5382. PMID 25025742.
  2. ^ Morgan, James (16 July 2014). "Four-winged dinosaur is 'biggest ever'". BBC News. Retrieved 16 July 2014.
  3. ^ Nicholas R. Longrich; David M. Martill; Brian Andres (2018). "Late Maastrichtian pterosaurs from North Africa and mass extinction of Pterosauria at the Cretaceous-Paleogene boundary". PLOS Biology. 16 (3): e2001663.
  4. ^ a b c d e f g Choi, Charles (15 July 2014). "Bizarre Dinosaur Had 4 'Wings,' Long Tail Feathers". LiveScience.com. Retrieved 16 July 2014.
  5. ^ a b c "New feathered predatory fossil sheds light on dinosaur flight". Phys.org. 15 July 2014. Retrieved 16 July 2014.
  6. ^ a b c d Pickrell, John (16 July 2014). "Four-winged dinosaur had record-breaking tail feathers". Australian Geographic Society. Retrieved 16 July 2014.
  7. ^ "New feathered dinosaur from China sheds light on dinosaur flight". ScienceDaily. 15 July 2014. Retrieved 16 July 2014.
  8. ^ a b Iacurci, Jenna (15 July 2014). "New Four-Winged Dinosaur Built for Flight". Nature World News. Retrieved 16 July 2014.
  9. ^ Welsh, Jennifer (4 April 2012). "'Shaggy' Tyrannosaur Now World's Biggest Feathered Beast". LiveScience.com. Retrieved 16 July 2014.
Dromaeosaurinae

Dromaeosaurinae is a subfamily of Dromaeosauridae. Most dromaeosaurines lived in what is now the United States and Canada, as well as Mongolia, and possibly Denmark as well. Isolated teeth that may belong to African dromaeosaurines have also been discovered in Ethiopia. These teeth date to the Tithonian stage, of the Late Jurassic Period.All North American and Asian dromaeosaurine dinosaurs from the Late Cretaceous were generally small, no more than 1.8 metres (5.9 ft) long, in Dromaeosaurus and Adasaurus. However, among the dromaeosaurines were the largest dromaeosaurs ever; Dakotaraptor was ~5.5 metres (18 ft) long, Achillobator 6 metres (20 ft), and Utahraptor up to ~7 metres (23 ft).

Graciliraptor

Graciliraptor (meaning "graceful thief") is a genus of theropod dinosaur from the early Cretaceous Period. It is a microraptorine dromaeosaurid.

The type species Graciliraptor lujiatunensis was first named and described in 2004 by Xu Xing and Wang Xiaoling. The generic name is derived from Latin gracilis and raptor. The specific name refers to the village Lujiatun where the fossil site is located. Its fossil, holotype IVPP V 13474, was found in Beipiao, Liaoning Province, China.

Halszkaraptorinae

Halszkaraptorinae is a basal ("primitive") subfamily of Dromaeosauridae that includes the enigmatic genera Halszkaraptor, Mahakala, and Hulsanpes. A comparison of the fossils of Halszkaraptor with the bones of extant crocodilians and aquatic birds revealed evidence of a semiaquatic lifestyle. The group is named after Polish paleontologist Halszka Osmólska.

Hulsanpes

Hulsanpes is a genus of dromaeosaurid theropod dinosaur from Mongolia that lived during the Late Cretaceous.

Itemirus

Itemirus is a genus of theropod dinosaur from the Turonian age of the Late Cretaceous period of Uzbekistan.

Linheraptor

Linheraptor is a genus of dromaeosaurid dinosaur which lived in what is now China in the Late Cretaceous. It was named by Xu Xing and colleagues in 2010, and contains the species Linheraptor exquisitus. This bird-like dinosaur was less than 2 m (6.5 ft) long and was found in Inner Mongolia. It is known from a single, nearly complete skeleton.

Luanchuanraptor

Luanchuanraptor (meaning "Luanchuan thief") is a genus of dromaeosaurid theropod dinosaur from the Late Cretaceous of China. It is based on a partial skeleton from the Qiupa Formation in Luanchuan, Henan. A medium-sized dromaeosaurid, it is the first Asian dromaeosaurid described from outside the Gobi Desert or northeastern China. The fossil material is cataloged as 4HIII-0100 in the Henan Geological Museum and includes four teeth, one frontal, a neck vertebra, one or two back vertebrae, seventeen tail vertebrae, ribs, chevrons, a humerus (upper arm bone), claw and finger bones, partial shoulder and pelvic girdles, and other fragmentary bones from a moderately sized dromaeosaurid. The type species is L. henanensis, described by Lü et al. in 2007.

Microraptoria

Microraptoria (Greek, μίκρος, mīkros: "small"; Latin, raptor: "one who seizes") is a clade of basal dromaeosaurid theropod dinosaurs. The first microraptorians appeared 125 million years ago in China. Many are known for long feathers on their legs and may have been semi-arboreal powered fliers, some of which even capable of launching from the ground. Most microraptorians were relatively small; adult specimens of Microraptor range between 77–90 centimetres long (2.53–2.95 ft) and weigh up to 1 kilogram (2.2 lb), making them some of the smallest known dinosaurs.

Pamparaptor

Pamparaptor is an extinct genus of carnivorous deinonychosaur from the late Cretaceous period. It is a basal dromaeosaurid dinosaur with troodontid-like pes which lived during the late Cretaceous period (Turonian to Coniacian stage) in what is now Neuquén province, Patagonia, Argentina. It is known from the holotype MUCPv-1163, an articulated and nearly complete left foot.

The specimen recovered from the Portezuelo Formation (Río Neuquén Subgroup) of Neuquén Group. It was initially considered to be a juvenile specimen of another dromaeosaurid species, Neuquenraptor argentinus. However, it was later re-interpreted as a new genus and named Pamparaptor by Juan D. Porfiri, Jorge O. Calvo and Domenica dos Santos in 2011 and the type species is Pamparaptor micros. The generic name honors Indian Pampas people who lived in central Argentina while "raptor" (robber in Latin). The specific name (micros, meaning "small") refers to the specimen's size (estimated at 0.5 to 0.7 metres (1.6 to 2.3 ft) in length).

Pyroraptor

Pyroraptor (meaning "fire thief") is a genus of dromaeosaurid dinosaur from the Late Cretaceous of what is now southern France, it lived during the late Campanian and early Maastrichtian stages, approximately 70.6 million years ago. It is known from a single partial specimen that was found in Provence in 1992. The animal was named Pyroraptor olympius by Allain and Taquet in 2000.

Saurornitholestinae

Saurornitholestinae is a subfamily of dromaeosaurid dinosaurs. The saurornitholestines currently include three monotypic genera: Atrociraptor marshalli, Bambiraptor feinbergorum, and Saurornitholestes langstoni. All are medium-sized dromaeosaurs from the Late Cretaceous of western North America. The group was originally recognized by Longrich and Currie as the sister taxon to a clade formed by the Dromaeosaurinae and Velociraptorinae. However, not all phylogenetic analyses recover this group.

Shanag

Shanag is a genus of dromaeosaurid theropod dinosaur from the Early Cretaceous Period of Mongolia.

The type species of Shanag is S. ashile. It was named and described by Alan Turner, Sunny Hai-Ching Hwang and Mark Norell in 2007. The generic name refers to the black-hatted dancers in the Buddhist Cham dance. The specific name refers to the Ashile Formation, the old name for the layers where Shanag was found, used by Henry Fairfield Osborn.The holotype of Shanag, IGM 100/1119, was discovered in the Öösh Formation, the stratification of which is uncertain but probably dating to the Berriasian-Barremian. Shanag bears a strong resemblance to basal Chinese dromaeosaurids such as Microraptor and Sinornithosaurus, suggesting a close similarity between the fauna of the Öösh deposits, dated tentatively to 130 million years ago, and the Jehol Biota of China (such as the animals found in the roughly contemporary Yixian Formation), during the Early Cretaceous. The holotype specimen, about six centimetres long, is composed of an associated uncompressed upper and lower jaw fragment, containing a nearly complete right maxilla with teeth, a partial right dentary with teeth and an attached partial splenial.Shanag was a small predator. In 2010 Gregory S. Paul estimated its length at 1.5 metres, the weight at five kilogrammes. Shanag shows a mixture of dromaeosaurid, troodontid and basal avialan traits.Turner et alii assigned Shanag to the Dromaeosauridae. Their cladistic analysis indicated that it was a basal dromaeosaurid but higher in the tree than the Unenlagiinae. Later analyses recovered it in the Microraptorinae.

Sinornithosaurus

Sinornithosaurus (derived from a combination of Latin and Greek, meaning 'Chinese bird-lizard') is a genus of feathered dromaeosaurid dinosaur from the early Cretaceous Period (early Aptian) of the Yixian Formation in what is now China. It was the fifth non–avian feathered dinosaur genus discovered by 1999. The original specimen was collected from the Sihetun locality of western Liaoning. It was found in the Jianshangou beds of the Yixian Formation, dated to 124.5 million years ago. Additional specimens have been found in the younger Dawangzhangzi bed, dating to around 122 million years ago.Xu Xing described Sinornithosaurus and performed a phylogenetic analysis which demonstrated that it is basal, or primitive, among the dromaeosaurs. He has also demonstrated that features of the skull and shoulder are very similar to Archaeopteryx and other Avialae. Together these two facts demonstrate that the earliest dromaeosaurs were more like birds than the later dromaeosaurs were.

Sinornithosaurus was among the smallest dromaeosaurids, with a length of about 90 centimetres (3.0 ft). In 2010, Gregory S. Paul gave higher estimations of 1.2 metres and three kilogrammes.

Timeline of dromaeosaurid research

This timeline of dromaeosaurid research is a chronological listing of events in the history of paleontology focused on the dromaeosaurids, a group of sickle-clawed, bird-like theropod dinosaurs including animals like Velociraptor. Since the Native Americans of Montana used the sediments of the Cloverly Formation to produce pigments, they may have encountered remains of the dromaeosaurid Deinonychus hundreds of years before these fossils came to the attention of formally trained scientists.In 1922 Matthew and Brown named the new genus and species Dromaeosaurus albertensis, considering it a new type within the family Deinodontidae, a now defunct family name that once applied to the tyrannosaurs. Not long after, Velociraptor was discovered in Mongolia by the Central Asiatic Expedition. Dromaeosaur research was fairly quiet until the 1960s, when John Ostrom described the new genus and species Deinonychus antirrhopus. This discovery played a major role in setting off the Dinosaur Renaissance because Deinonychus was obviously a vigorous, active animal, and exhibited characteristics linking it to the origin of birds. As such it brought support for controversial reinterpretations of dinosaurs as warm-blooded and ancestral to birds. Its distinct nature and similarity to Dromaeosaurus led Ostrom to follow Edwin Colbert and Dale Russel's suggestion that the Dromaeosaurinae be regarded as its own family separate from the Deinodontidae.After Ostrom's initial research on Deinonychus, evidence continued to mount for a close evolutionary relationship between dromaeosaurids and birds. The dromaeosaurid Sinornithosaurus milennii, described in 1999 by Xu, Wang, and Wu, is a notable example as the fine-grained Chinese limestone from which it was collected preserved its life covering of feathers. Discoveries of feathered dromaeosaurids continued into the 2000s. Xu, Zhou, and Wang named the new genus Microraptor in 2000. Three years later, Xu and others would report a new species in this genus that exhibited a bizarre "four winged" body plan with long pennaceous flight feathers on both its front and hind limbs.

Unenlagiinae

Unenlagiinae is a subfamily of dromaeosaurid theropods. Unenlagiines are known from South America and Antarctica.

Unquillosaurus

Unquillosaurus (meaning "Unquillo river lizard") is a genus of maniraptoran dinosaur from the Late Cretaceous Period, discovered in Argentina. Known only from a single fossilized pubis (a pelvic bone), its total body length may have reached 2 to 3 metres (6.6 to 9.8 ft).

Variraptor

Variraptor ( VARR-i-rap-tor; "Var thief") is a genus of coelurosaurian theropod dinosaur from the Late Cretaceous of France.

Yurgovuchia

Yurgovuchia is an extinct genus of dromaeosaurid theropod dinosaur known from the Early Cretaceous (probably Barremian stage) of Utah. It contains a single species, Yurgovuchia doellingi. According to a phylogenetic analysis performed by its describers, it represents an advanced dromaeosaurine, closely related to Achillobator, Dromaeosaurus and Utahraptor.

Zhenyuanlong

Zhenyuanlong (meaning "Zhenyuan's dragon", from Chinese Pinyin 龙 lóng "dragon") is a genus of dromaeosaurid dinosaur from the Yixian Formation of Liaoning, China. It lived during the Aptian age of the early Cretaceous period, approximately 125 million years ago. It is known from a single specimen belonging to the species Zhenyuanlong suni (Chinese: 孫氏振元龍). This type specimen preserved a nearly complete skeleton that contains traces of feathers, including long tail feathers and large wings. In addition to further complicating diversity of Liaoning dromaeosaurids, this specimen provides the first evidence of well-developed pennaceous feathers in a large, non-flying dromaeosaur, raising the question of what function such wings would serve.

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