Ambopteryx Temporal range: Late Jurassic, | |
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Life restoration of Ambopteryx | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | Theropoda |
Family: | † Scansoriopterygidae |
Genus: | † Ambopteryx Wang et al., 2019 |
Species: | †A. longibrachium |
Binomial name | |
†Ambopteryx longibrachium Wang et al., 2019 | |
Ambopteryx (meaning "both wing") is a genus of scansoriopterygid dinosaur from the Oxfordian stage of the Late Jurassic of China. It is the second dinosaur to be found with both feathers and bat-like membranous wings. Yi, the first such dinosaur, was described in 2015 and is the sister taxon to Ambopteryx. The holotype specimen is thought to be a sub-adult or adult. The specimen is estimated to have had a body length of 32 centimetres (13 in) and a weight of 306 grams (10.8 oz). The genus includes one species, Ambopteryx longibrachium. [1]
The generic name Ambopteryx is derived from the Latin word ambo meaning "both" and Ancient Greek word πτέρυξ (pteryx) meaning "wing", a reference to the animal's membranous wings and bird-like body plan. The specific name longibrachium is derived from the Latin words longus meaning "long" and brachium meaning "upper arm". [1]
The holotype specimen, IVPP V24192, is an articulated and nearly complete skeleton with associated soft tissue preserved on a slab and a counter slab. It was recovered in 2017 from the stratigraphic equivalent of the Haifanggou Formation near Wubaiding Village in the Liaoning Province and belongs to the Yanliao Biota. [1]
The type specimen is interpreted as either a subadult or an adult based on the fusion of the pygostyle. Its wing membrane is preserved as a continuous brownish layer on the matrix surrounding the left hand, right forelimb, and abdomen. The head, neck, and shoulder regions are covered with dense layers of feather. [1]
Like other scansoriopterygids, Ambopteryx had a short, blunt head and a hyper-elongate third finger. It was previously believed that scansoriopterygids used their third finger to extract grubs from wood, like the extant aye-aye. However, Wang et al. think the primary function of the third finger was the attachment of the wing membrane, or patagium, as their fingers were probably surrounded by membranous tissue and had limited mobility. [1]
Among scansoriopterygids, Ambopteryx was most closely related to Yi, with which it shared a "styliform element", an elongate bone that extended from the distal (far) end of the ulna. The styliform element was slightly curved and tapered towards the distal end. It supported the wing membrane, which stretched from the third finger down to the abdomen. [1]
The forelimbs of Ambopteryx were about 1.3 times longer than the hindlimbs, with the ulna being shorter than the humerus and almost twice as wide as the width of the radius. Unlike most other non-avian theropods, it had a short tail that lacked a transitional point and ended in a pygostyle, a set of fused tail vertebrae. The only other non-avian theropod that are known to have had a pygostyle are certain oviraptorosaurs and therizinosaurs. [1]
The abdominal region of Ambopteryx contains a small number of gastroliths and large fragments of what appears to be bone. The bone probably represents stomach contents. Previously, the diet of scansoriopterygids was unknown but their unusual dental morphology and the presence of gastroliths and possible bone fragments in Ambopteryx suggests they were omnivorous. [1]
Theropoda, whose members are known as theropods, is an extant dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago (Ma) and included the majority of large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by about 11,000 living species.
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Deinocheirus is a genus of large ornithomimosaur that lived during the Late Cretaceous around 70 million years ago. In 1965, a pair of large arms, shoulder girdles, and a few other bones of a new dinosaur were first discovered in the Nemegt Formation of Mongolia. In 1970, this specimen became the holotype of the only species within the genus, Deinocheirus mirificus; the genus name is Greek for "horrible hand". No further remains were discovered for almost fifty years, and its nature remained a mystery. Two more complete specimens were described in 2014, which shed light on many aspects of the animal. Parts of these new specimens had been looted from Mongolia some years before, but were repatriated in 2014.
The patagium is a membranous body part that assists an animal in obtaining lift when gliding or flying. The structure is found in extant and extinct groups of flying and gliding animals including bats, theropod dinosaurs, pterosaurs, gliding mammals, some flying lizards, and flying frogs. The patagium that stretches between an animal's hind limbs is called the uropatagium or the interfemoral membrane.
Anurognathus is an extinct genus of small pterosaur from the Late Jurassic Altmühltal Formation of Germany.
Yixianosaurus is a maniraptoran theropod dinosaur genus from the Early Cretaceous of China.
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Scansoriopterygidae is an extinct family of climbing and gliding maniraptoran dinosaurs. Scansoriopterygids are known from five well-preserved fossils, representing four species, unearthed in the Tiaojishan Formation fossil beds of Liaoning and Hebei, China.
Sinocalliopteryx is a genus of carnivorous compsognathid theropod dinosaurs from the Lower Cretaceous Yixian Formation of China.
Sinornis is a genus of enantiornithean birds from the Lower Cretaceous Jiufotang Formation of the People's Republic of China.
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