| Qijianglong Temporal range: Early Cretaceous, | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | † Sauropodomorpha |
| Clade: | † Sauropoda |
| Family: | † Mamenchisauridae |
| Genus: | † Qijianglong Xing et al., 2015 |
| Type species | |
| Qijianglong guokr Xing et al., 2015 | |
Qijianglong is a genus of herbivorous mamenchisaurid sauropod dinosaur [1] from the Early Cretaceous of China. [2]
A vertebra of Qijianglong was first discovered in the early 1990s by farmer Cai Changming of Heba village, Sichuan, in his backyard. Work at a nearby construction site at Qijiang District uncovered a rich fossil quarry in 2006. Its excavation caused an examination of the earlier find which led to the discovery of a skeleton. In 2015, the type species Qijianglong guokr was named and described by Xing Lida (China University of Geosciences), Tetsuto Miyashita (University of Alberta), Zhang Jianping, Li Daqing, Ye Yong (Zigong Dinosaur Museum), Toru Sekiya (Fukui Prefectural Dinosaur Museum), Wang Fengping and Philip John Currie. The generic name combines the district Qijiang with Mandarin long, "dragon". The specific name guokr, "nutshell", is that of a Chinese scientific social network. [1]
The holotype QJGPM 1001 was found in a layer of the Suining Formation, which was seen as dating from the Late Jurassic but is now considered mid-Cretaceous (late Aptian) based on radiometric dating. [2] It consists of a partial skeleton with a skull. It includes the rear of the skull, a partial right lower jaw, a complete series of seventeen neck vertebrae, the first six back vertebrae, ribs, the probable tenth tail vertebra, a series of twenty-eight rear tail vertebrae, chevrons, the left pubic bone and two upper pedal phalanges. It likely represents a juvenile individual, large but immature. [1]
The holotype of Qijianglong was about fifteen meters long and had a long neck. The describing authors established several distinguishing traits among which four autapomorphies. On the lower braincase the processus basipterygoideus has the form of a plate, is oriented along the body axis, and has an additional boss parallel to the tubera basilaria. The neck vertebrae have rear joint processes, postzygapophyses that next to their normal facets show on the outside an additional finger-shaped extension, stiffening the neck in the horizontal plane but allowing vertical movement. The rear neck vertebrae have pneumatopores, pneumatic openings, in the depression between the diapophysis, the upper rib joint process, and the neural spine. The pubic bone has a concave front edge, curving so strongly that its lower end is more directed to the front than to below. [1]
Qijianglong was placed in the family Mamenchisauridae, in a relatively basal position but above Omeisaurus tianfuensis in the evolutionary tree. [1]
Mamenchisaurus is a genus of sauropod dinosaur known for their remarkably long necks which made up nearly half the total body length. Numerous species have been assigned to the genus; however, the validity of these assignments has been questioned. Fossils have been found in the Sichuan Basin and Yunnan Province in China. Several species from the Upper Shaximiao Formation, whose geologic age is uncertain, have been described. However, evidence suggests this formation to be no earlier than the Oxfordian stage of the Late Jurassic. M. sinocanadorum dates to the Oxfordian stage, and M. anyuensis to the Aptian stage of the Early Cretaceous. Most species were medium-large to large sauropods, measuring roughly 15 to 26 meters in length—possibly up to 35 meters (115 ft), based on two undescribed vertebrae.
Euhelopus is a genus of sauropod dinosaur that lived between 145 and 133 million years ago during the Berriasian and Valanginian stages of the Early Cretaceous in what is now Shandong Province in China. It was a large quadrupedal herbivore. Like sauropods such as brachiosaurs and titanosaurs, Euhelopus had longer forelegs than hind legs. This discovery was paleontologically significant because it represented the first dinosaur scientifically investigated from China: seen in 1913, rediscovered in 1922, and excavated in 1923 and studied by T'an during the same year. Unlike most sauropod specimens, it has a relatively complete skull.
Yunnanosaurus is an extinct genus of sauropodomorph dinosaur that lived approximately 199 to 183 million years ago in what is now the Yunnan Province, in China, for which it was named. Yunnanosaurus was a large sized, moderately-built, ground-dwelling, quadrupedal herbivore, that could also walk bipedally, and ranged in size from 7 meters (23 feet) long and 2 m (6.5 ft) high to 4 m (13 ft) high in the largest species.
Omeisaurus is a genus of sauropod dinosaur from the Middle Jurassic Period of what is now China. Its name comes from Mount Emei, where it was discovered in the lower Shaximiao Formation of Sichuan Province.
Atlasaurus is a genus of sauropod dinosaurs from Middle Jurassic beds in North Africa.
Sinusonasus is a genus of dinosaurs from the Early Cretaceous Period, recovered from the Yixian Formation. It lived in what is now the Liaoning Province of China. Sinusonasus was a theropod, specifically a troodontid dinosaur.
Yuanmousaurus was a sauropod dinosaur from the Middle Jurassic period of China. It is known from incomplete remains, recovered in 2000 from the Zhanghe Formation in Yuanmou County in Yunnan Province. Yuanmousaurus was a relatively large sauropod and may have reached about 17 meters (56 ft) in length. It was a basal member of the Sauropoda, but its exact systematic position is unclear. A recent study placed Yuanmousaurus within the family Mamenchisauridae. It may be a dubious genus. The only and type species was Yuanmousaurus jiangyiensis.
The Suining Formation is a geological formation in China whose strata date back to the Early Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. A 2019 paper shows zircon dating of the Suining Formation with a much younger age for the classically thought of Late Jurassic formation; the average age of the dating being roughly 114 myo or late upper Aptian.
Daxiatitan is a genus of sauropod dinosaur known from the Lower Cretaceous of Gansu, China. Its type and only species is Daxiatitan binglingi. It is known from a single partial skeleton consisting of most of the neck and back vertebrae, two tail vertebrae, a shoulder blade, and a thigh bone. At the time of its discovery in 2008, Daxiatitan was regarded as potentially the largest known dinosaur from China.
Mamenchisauridae is a family of sauropod dinosaurs belonging to Eusauropoda known from the Jurassic and Early Cretaceous of Asia and Africa. Some members of the group reached gigantic sizes, amongst the largest of all sauropods.
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Tonganosaurus is a genus of mamenchisaurid sauropod dinosaur, similar to Omeisaurus. It is known from one specimen consisting of twenty vertebrae, a front limb and pectoral girdle, and a complete hind limb with partial hip. It was discovered in the Yimen Formation, China. The horizon of the specimen and the age of the Yimen Formation is controversial. The formation has been divided into three levels, and Tonganosaurus appears to be of late Early Jurassic (Pliensbachian) age. Tonganosaurus is the oldest known member of the mamenchisaurids, being almost 15 million years older than the next-oldest members of the group. It was first named by Li Kui, Yang Chun-Yan, Liu Jian and Wang Zheng-Xin in 2010 and the type species is Tonganosaurus hei.
Xinjiangtitan is an extinct genus of mamenchisaurid sauropod that lived during the Middle Jurassic of what is now Xinjiang, northwestern China. Its type and only species is Xinjiangtitan shanshanesis, known from a single incomplete skeleton recovered from the Qiketai Formation. The holotype preserves one of the most complete vertebral columns of any sauropod found in Asia, and has the longest complete neck known for any animal.
Yongjinglong is an extinct genus of titanosauriform sauropod dinosaur known from the Early Cretaceous of Lanzhou-Minhe Basin of Gansu Province, China. It contains a single species, Yongjinglong datangi.
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Mansourasaurus is a genus of herbivorous lithostrotian sauropod dinosaur from the Quseir Formation of Egypt. The type and only species is Mansourasaurus shahinae.
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Ruixinia is an extinct genus of somphospondylan titanosauriform dinosaur from the Early Cretaceous (Barremian) Yixian Formation of China. The genus contains a single species, Ruixinia zhangi. The Ruixinia holotype is a partial articulated skeleton with the most complete series of caudal vertebrae known from any Asian titanosauriform.
Baiyinosaurus is an extinct genus of stegosaurian dinosaurs from the Middle Jurassic Wangjiashan Formation of China. The genus contains a single species, B. baojiensis, known from a partial skeleton including cranial bones. The skeletal anatomy of Baiyinosaurus demonstrates transitional features between basal thyreophorans and stegosaurs. While many stegosaurs are known from China, Baiyinosaurus is the only one currently named from Gansu Province.
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