Post by Eaglehawk on Jan 11, 2020 5:49:11 GMT
Yi qi
Temporal range: Middle Jurassic, 160Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Suborder: Theropoda
Family: †Scansoriopterygidae
Genus: †Yi
Species: † Y. qi
Yi qi ("strange wing") is a species of gliding scansoriopterygid dinosaur. Y. qi is known from a single fossil specimen of an adult individual found in late Jurassic period rocks in Hebei, China. It was a small, tree-dwelling (arboreal) animal. Like other scansoriopterygids, it possessed an unusual, elongated third finger that helped to support a membranous wing made of skin. The wings of Yi qi were also supported by a long, bony strut attached to the wrist. This modified wrist bone and membrane-based wing is unique among all known dinosaurs, and made the wings of Yi qi similar in appearance to those of bats.
The fossil of Yi qi (above) was so well preserved that bristle-like feathers and the remains of its membrane wings could be seen around the bones. The strange long bone extending from the wrist was highly unusual.
Description
Yi qi is known only from a single partial skeleton (STM 31-2) currently in the collections of the Shandong Tianyu Museum of Nature. It was a relatively small animal, estimated to weigh about 380 grams (0.84 lb).
Like other scansoriopteyrgids, the head was short and blunt-snouted, with a downturned lower jaw. Its few teeth were present only in the tips of the jaws, with the upper front teeth being the largest and slightly forward-pointing, and the front lower teeth were angled even more strongly forward. The long, slender forelimbs were similar, overall, to most other paravian dinosaurs. Like other scansoriopterygid dinosaurs, the first finger was shortest and the third was the longest. Unlike all other known dinosaurs, a long, pointed wrist bone known as a "styliform element" extended backward from the forelimb bones. This styliform, an adaptation to help support the wing membrane, may have been a newly evolved wrist bone, or a calcified rod of cartilage.
The only known specimen of Yi qi preserved a heavy covering of feathers. Unusually based on its classification as an advanced theropod in the clade Pennaraptora (a group containing theropods with advanced, bird-like feathers), the feathers were all very simple in structure and "paintbrush-like", with long quill-like bases topped by sprays of thinner filaments. The feathers covered most of the body, starting near the tip of the snout. The head and neck feathers were long and formed a thick coat, and the body feathers were even longer and denser, making it difficult for scientists to study their detailed structure. Small patches of skin were also preserved between the fingers and the styliform bone, indicating that unlike all other known winged dinosaurs, the wings of Yi qi were formed by a skin membrane rather than flight feathers. The membrane stretched between the shorter fingers, the elongated third finger, the styliform bone, and possibly connected to the torso, though the inner part of the wing membrane was not preserved in the only known fossil. This would have given the wings a similar appearance to those of modern bats, in an example of convergent evolution. However, in bats, the wing membrane stretches between the fingers, not a styliform wrist bone. Styliform bones are also found in the wings of some modern gliding animals like flying squirrels, the Greater glider, and the prehistoric gliding rodent Eomys quercyi.
This close up of the skull of Yi qi, which weighed just 13 ounces (380g), show oval like feathers near the head
Paleobiology
The strange membranous wings of Yi qi are unique among dinosaurs and difficult to interpret. The presence of a long styliform bone adding support to the membrane, found only in other animals that glide, suggests that Yi qi was specialized for gliding flight. While it is possible that some form of flapping flight was also used by this animal, the lack of evidence for large pectoral muscles, and the cumbersome nature of the styliform, make it more likely that Yi qi was an exclusive glider. At best, the researchers who conducted the initial study of the only known Yi specimen concluded that its mode of flight should be considered uncertain.
Yi qi, and presumably other scansoriopterygids, possessed a type of wing unknown among any other prehistoric bird relatives. Unlike other paravian dinosaurs, they seem to have replaced bird-like feathers with membranous wings, in what may have been one of many independent evolutionary experiments with flight close to the origin of birds.
Paleoecology
The only known Yi qi fossil was found in rocks assigned to the Tiaojishan Formation, dating to the Callovian-Oxfordian age of the Middle-Late Jurassic, dated to between 165 and 153 million years ago. This is the same formation/age as the other known scansoriopterygids Epidexipteryx and Scansoriopteryx. The ecosystem preserved in the Tiaojishan Formation is a forest dominated by bennettitales, ginkgo trees, conifers, and leptosporangiate ferns. These forests surrounded large lakes in the shadow of active volcanoes, ash from which was responsible for the remarkable preservation of many of the fossils. Based on the Tiajishan's plant life, its climate would have been subtropical to temperate, warm and humid. Besides the scansoriopterygids, land vertebrate fauna in the Tiaojishan ecosystem would have included a variety of salamanders (like Liaoxitriton and Jeholotriton), primitive mammals and mammal relatives (including Juramaia, the burrowing Docofossor, and the gliding Volaticotherium), flying pterosaurs like Darwinopterus and Jeholopterus, and dinosaurs (including Anchiornis and Tianyulong).
History
The first and only known fossil specimen of Yi qi was found by a farmer, Wang Jianrong, in a quarry near Mutoudeng Village (Qinglong County, Hebei). Wang sold the fossil to the Shandong Tianyu Museum of Nature in 2007, at which point Ding Xiaoqing, a technician at the museum, began further preparation of the fossil. Because many of the unique features and soft tissues of the specimen were uncovered by museum staff during preparation rather than amateur fossil sellers, the scientists who studied it were confident that it was authentic and unaltered.
A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings
Xing Xu, Xiaoting Zheng, Corwin Sullivan, Xiaoli Wang, Lida Xing, Yan Wang, Xiaomei Zhang, Jingmai K. O’Connor, Fucheng Zhang & Yanhong Pan
Nature (2015) doi:10.1038/nature14423
Received 11 February 2015 Accepted 20 March 2015 Published online 29 April 2015
Article metrics
The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component1, 2, 3. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle–Upper Jurassic period Tiaojishan Formation of Hebei Province, China4. Yi is nested phylogenetically among winged theropods but has large stiff filamentous feathers of an unusual type on both the forelimb and hindlimb. However, the filamentous feathers of Yi resemble pinnate feathers in bearing morphologically diverse melanosomes5. Most surprisingly, Yi has a long rod-like bone extending from each wrist, and patches of membranous tissue preserved between the rod-like bones and the manual digits. Analogous features are unknown in any dinosaur but occur in various flying and gliding tetrapods6, 7, 8, 9, 10, suggesting the intriguing possibility that Yi had membranous aerodynamic surfaces totally different from the archetypal feathered wings of birds and their closest relatives. Documentation of the unique forelimbs of Yi greatly increases the morphological disparity known to exist among dinosaurs, and highlights the extraordinary breadth and richness of the evolutionary experimentation that took place close to the origin of birds.
The diagrams above show how the wing of Yi qi (a) compares to other winged tetrapods (b and c) and the wing of a bat (d), the wing of a pigeon (e), the wing of a pterosaur (f) and the wing of a Japanese flying squirrel (g)
www.nature.com/nature/journal/vaop/ncurrent/full/nature14423.html
Tiny Dinosaur Had Batlike Wings
by Tanya Lewis, Staff Writer | April 29, 2015 01:02pm ET
Move over, Batman — there's a new Dark Knight in town. A tiny dinosaur with batlike wings may have glided through the Jurassic forests of what is now northeastern China, say paleontologists who analyzed the animal's bones.
Unlike any dinosaur ever found, the feathered pipsqueak may have been a failed experiment in early bird flight, the researchers say.
Unlike its close relatives — birds and birdlike dinosaurs — the new specimen had long, rodlike bones on its wrists connected by soft, fleshy tissue.
The creature is the first known dinosaur with membranous wings, said Xing Xu, a paleontologist at Linyi University in China, and co-author of the study published today (April 29) in the journal Nature.
"This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career," Xu told Live Science in an email.
However, due to the dinosaur's strange body plan, the findings are likely to be controversial, some scientists say.
The fossil comes from the Middle-Upper Jurassic period (about 160 million years ago), and was found by a farmer, in the Tiaojishan Formation of Hebei Province, China. The specimen's authenticity was confirmed by multiple lines of evidence, the researchers wrote.
Xu and his colleagues named the new species Yi qi (pronounced ee chee), which means "strange wing" in Chinese. Yi qi belongs to a group of dinosaurs called theropods that were mostly carnivorous, and fits into subgroup of tiny, feathered dinosaurs called scansoriopterygids.The researchers estimate the creature weighed less than a pound (380 grams).
Xu's team noticed unusually long, rodlike bones extending from each of the creature's wrists connected by patches of soft, membranous tissue, neither of which have been seen in any other dinosaur. In fact, these bones have been found only in flying or gliding four-legged creatures, such as flying squirrels and bats. The specimen also had feathers, but not the kind used for flight, the researchers said.
Yi qi probably wasn't a great flyer, and most likely moved through the air by a combination of flapping and gliding, Xu said. This was "a failed experiment in flight along the line to birds," Xu said, "but we don't know why [it failed]." During the early evolution of birdlike dinosaurs, many different body plans arose, but only feathered wings went on to give rise to modern birds, possibly because they were more efficient than the batlike wings, Xu said.
Some scientists praised the finding, while others were more skeptical.
"This is an astounding discovery, and I think it's one of the most unexpected and downright bizarre dinosaurs that has been found over the past few years," Stephen Brusatte, a paleontologist at the University of Edinburgh in Scotland, who was not involved in the study, told Live Science.The findings suggest flight probably evolved many times among dinosaurs, but only one group — birds — were able to endure, he said.
However, the study will likely stir debate in the scientific community, said Luis Chiappe, a paleontologist and director of the Dinosaur Institute at the Natural History Museum of Los Angeles County, who had no part in the study but was a former advisor to one of the authors.
Many fossils from sites in China have been tinkered with or enhanced, Chiappe told Live Science. "I'm not saying this fossil has been tampered [with]," he said, but "because of this being a very odd body plan, it's going to be quite controversial and hard to swallow."
Chiappe also pointed out that the researchers' placement of the specimen in the theropod family tree might be too narrow. A "more holistic approach" might reveal that the animal was a different kind of dinosaur, or perhaps not a dinosaur at all, he said.
www.livescience.com/50663-bat-winged-dinosaur.html
Temporal range: Middle Jurassic, 160Ma
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Suborder: Theropoda
Family: †Scansoriopterygidae
Genus: †Yi
Species: † Y. qi
Yi qi ("strange wing") is a species of gliding scansoriopterygid dinosaur. Y. qi is known from a single fossil specimen of an adult individual found in late Jurassic period rocks in Hebei, China. It was a small, tree-dwelling (arboreal) animal. Like other scansoriopterygids, it possessed an unusual, elongated third finger that helped to support a membranous wing made of skin. The wings of Yi qi were also supported by a long, bony strut attached to the wrist. This modified wrist bone and membrane-based wing is unique among all known dinosaurs, and made the wings of Yi qi similar in appearance to those of bats.
The fossil of Yi qi (above) was so well preserved that bristle-like feathers and the remains of its membrane wings could be seen around the bones. The strange long bone extending from the wrist was highly unusual.
Description
Yi qi is known only from a single partial skeleton (STM 31-2) currently in the collections of the Shandong Tianyu Museum of Nature. It was a relatively small animal, estimated to weigh about 380 grams (0.84 lb).
Like other scansoriopteyrgids, the head was short and blunt-snouted, with a downturned lower jaw. Its few teeth were present only in the tips of the jaws, with the upper front teeth being the largest and slightly forward-pointing, and the front lower teeth were angled even more strongly forward. The long, slender forelimbs were similar, overall, to most other paravian dinosaurs. Like other scansoriopterygid dinosaurs, the first finger was shortest and the third was the longest. Unlike all other known dinosaurs, a long, pointed wrist bone known as a "styliform element" extended backward from the forelimb bones. This styliform, an adaptation to help support the wing membrane, may have been a newly evolved wrist bone, or a calcified rod of cartilage.
The only known specimen of Yi qi preserved a heavy covering of feathers. Unusually based on its classification as an advanced theropod in the clade Pennaraptora (a group containing theropods with advanced, bird-like feathers), the feathers were all very simple in structure and "paintbrush-like", with long quill-like bases topped by sprays of thinner filaments. The feathers covered most of the body, starting near the tip of the snout. The head and neck feathers were long and formed a thick coat, and the body feathers were even longer and denser, making it difficult for scientists to study their detailed structure. Small patches of skin were also preserved between the fingers and the styliform bone, indicating that unlike all other known winged dinosaurs, the wings of Yi qi were formed by a skin membrane rather than flight feathers. The membrane stretched between the shorter fingers, the elongated third finger, the styliform bone, and possibly connected to the torso, though the inner part of the wing membrane was not preserved in the only known fossil. This would have given the wings a similar appearance to those of modern bats, in an example of convergent evolution. However, in bats, the wing membrane stretches between the fingers, not a styliform wrist bone. Styliform bones are also found in the wings of some modern gliding animals like flying squirrels, the Greater glider, and the prehistoric gliding rodent Eomys quercyi.
This close up of the skull of Yi qi, which weighed just 13 ounces (380g), show oval like feathers near the head
Paleobiology
The strange membranous wings of Yi qi are unique among dinosaurs and difficult to interpret. The presence of a long styliform bone adding support to the membrane, found only in other animals that glide, suggests that Yi qi was specialized for gliding flight. While it is possible that some form of flapping flight was also used by this animal, the lack of evidence for large pectoral muscles, and the cumbersome nature of the styliform, make it more likely that Yi qi was an exclusive glider. At best, the researchers who conducted the initial study of the only known Yi specimen concluded that its mode of flight should be considered uncertain.
Yi qi, and presumably other scansoriopterygids, possessed a type of wing unknown among any other prehistoric bird relatives. Unlike other paravian dinosaurs, they seem to have replaced bird-like feathers with membranous wings, in what may have been one of many independent evolutionary experiments with flight close to the origin of birds.
Paleoecology
The only known Yi qi fossil was found in rocks assigned to the Tiaojishan Formation, dating to the Callovian-Oxfordian age of the Middle-Late Jurassic, dated to between 165 and 153 million years ago. This is the same formation/age as the other known scansoriopterygids Epidexipteryx and Scansoriopteryx. The ecosystem preserved in the Tiaojishan Formation is a forest dominated by bennettitales, ginkgo trees, conifers, and leptosporangiate ferns. These forests surrounded large lakes in the shadow of active volcanoes, ash from which was responsible for the remarkable preservation of many of the fossils. Based on the Tiajishan's plant life, its climate would have been subtropical to temperate, warm and humid. Besides the scansoriopterygids, land vertebrate fauna in the Tiaojishan ecosystem would have included a variety of salamanders (like Liaoxitriton and Jeholotriton), primitive mammals and mammal relatives (including Juramaia, the burrowing Docofossor, and the gliding Volaticotherium), flying pterosaurs like Darwinopterus and Jeholopterus, and dinosaurs (including Anchiornis and Tianyulong).
History
The first and only known fossil specimen of Yi qi was found by a farmer, Wang Jianrong, in a quarry near Mutoudeng Village (Qinglong County, Hebei). Wang sold the fossil to the Shandong Tianyu Museum of Nature in 2007, at which point Ding Xiaoqing, a technician at the museum, began further preparation of the fossil. Because many of the unique features and soft tissues of the specimen were uncovered by museum staff during preparation rather than amateur fossil sellers, the scientists who studied it were confident that it was authentic and unaltered.
A bizarre Jurassic maniraptoran theropod with preserved evidence of membranous wings
Xing Xu, Xiaoting Zheng, Corwin Sullivan, Xiaoli Wang, Lida Xing, Yan Wang, Xiaomei Zhang, Jingmai K. O’Connor, Fucheng Zhang & Yanhong Pan
Nature (2015) doi:10.1038/nature14423
Received 11 February 2015 Accepted 20 March 2015 Published online 29 April 2015
Article metrics
The wings of birds and their closest theropod relatives share a uniform fundamental architecture, with pinnate flight feathers as the key component1, 2, 3. Here we report a new scansoriopterygid theropod, Yi qi gen. et sp. nov., based on a new specimen from the Middle–Upper Jurassic period Tiaojishan Formation of Hebei Province, China4. Yi is nested phylogenetically among winged theropods but has large stiff filamentous feathers of an unusual type on both the forelimb and hindlimb. However, the filamentous feathers of Yi resemble pinnate feathers in bearing morphologically diverse melanosomes5. Most surprisingly, Yi has a long rod-like bone extending from each wrist, and patches of membranous tissue preserved between the rod-like bones and the manual digits. Analogous features are unknown in any dinosaur but occur in various flying and gliding tetrapods6, 7, 8, 9, 10, suggesting the intriguing possibility that Yi had membranous aerodynamic surfaces totally different from the archetypal feathered wings of birds and their closest relatives. Documentation of the unique forelimbs of Yi greatly increases the morphological disparity known to exist among dinosaurs, and highlights the extraordinary breadth and richness of the evolutionary experimentation that took place close to the origin of birds.
The diagrams above show how the wing of Yi qi (a) compares to other winged tetrapods (b and c) and the wing of a bat (d), the wing of a pigeon (e), the wing of a pterosaur (f) and the wing of a Japanese flying squirrel (g)
www.nature.com/nature/journal/vaop/ncurrent/full/nature14423.html
Tiny Dinosaur Had Batlike Wings
by Tanya Lewis, Staff Writer | April 29, 2015 01:02pm ET
Move over, Batman — there's a new Dark Knight in town. A tiny dinosaur with batlike wings may have glided through the Jurassic forests of what is now northeastern China, say paleontologists who analyzed the animal's bones.
Unlike any dinosaur ever found, the feathered pipsqueak may have been a failed experiment in early bird flight, the researchers say.
Unlike its close relatives — birds and birdlike dinosaurs — the new specimen had long, rodlike bones on its wrists connected by soft, fleshy tissue.
The creature is the first known dinosaur with membranous wings, said Xing Xu, a paleontologist at Linyi University in China, and co-author of the study published today (April 29) in the journal Nature.
"This is the most unexpected discovery I have ever made, even though I have found a few really bizarre dinosaurs in my career," Xu told Live Science in an email.
However, due to the dinosaur's strange body plan, the findings are likely to be controversial, some scientists say.
The fossil comes from the Middle-Upper Jurassic period (about 160 million years ago), and was found by a farmer, in the Tiaojishan Formation of Hebei Province, China. The specimen's authenticity was confirmed by multiple lines of evidence, the researchers wrote.
Xu and his colleagues named the new species Yi qi (pronounced ee chee), which means "strange wing" in Chinese. Yi qi belongs to a group of dinosaurs called theropods that were mostly carnivorous, and fits into subgroup of tiny, feathered dinosaurs called scansoriopterygids.The researchers estimate the creature weighed less than a pound (380 grams).
Xu's team noticed unusually long, rodlike bones extending from each of the creature's wrists connected by patches of soft, membranous tissue, neither of which have been seen in any other dinosaur. In fact, these bones have been found only in flying or gliding four-legged creatures, such as flying squirrels and bats. The specimen also had feathers, but not the kind used for flight, the researchers said.
Yi qi probably wasn't a great flyer, and most likely moved through the air by a combination of flapping and gliding, Xu said. This was "a failed experiment in flight along the line to birds," Xu said, "but we don't know why [it failed]." During the early evolution of birdlike dinosaurs, many different body plans arose, but only feathered wings went on to give rise to modern birds, possibly because they were more efficient than the batlike wings, Xu said.
Some scientists praised the finding, while others were more skeptical.
"This is an astounding discovery, and I think it's one of the most unexpected and downright bizarre dinosaurs that has been found over the past few years," Stephen Brusatte, a paleontologist at the University of Edinburgh in Scotland, who was not involved in the study, told Live Science.The findings suggest flight probably evolved many times among dinosaurs, but only one group — birds — were able to endure, he said.
However, the study will likely stir debate in the scientific community, said Luis Chiappe, a paleontologist and director of the Dinosaur Institute at the Natural History Museum of Los Angeles County, who had no part in the study but was a former advisor to one of the authors.
Many fossils from sites in China have been tinkered with or enhanced, Chiappe told Live Science. "I'm not saying this fossil has been tampered [with]," he said, but "because of this being a very odd body plan, it's going to be quite controversial and hard to swallow."
Chiappe also pointed out that the researchers' placement of the specimen in the theropod family tree might be too narrow. A "more holistic approach" might reveal that the animal was a different kind of dinosaur, or perhaps not a dinosaur at all, he said.
www.livescience.com/50663-bat-winged-dinosaur.html