| Yandusaurus Temporal range: Middle Jurassic, | |
|---|---|
 | |
| Life reconstruction of Yandusaurus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | † Ornithischia |
| Clade: | † Neornithischia |
| Genus: | † Yandusaurus He, 1979 |
| Species: | †Y. hongheensis |
| Binomial name | |
| †Yandusaurus hongheensis He, 1979 | |
Yandusaurus is a genus of herbivorous basal neornithischian dinosaur from the Bathonian age (middle Jurassic, approximately 168 to 162 Ma) of China.
In January 1973 the Museum of the Salt Industry at Zigong in Sichuan was warned that during construction activities with a composter at Jinzidang near the Honghe dam inadvertently a dinosaur skeleton had been processed. A team of the museum managed to salvage some heavily damaged remains. Though locally this animal was at first referred to as "Yubasaurus" or "Honghesaurus", in 1979 Beijing professor He Xinlu named and described it as the type species Yandusaurus hongheensis. The generic name is derived from Yandu, the ancient name for Zigong. This name is a contraction of yan, "salt", and du, "capital", occasioned by the fact that Zigong was historically the centre of Chinese salt mining. In this way Yandusaurus indirectly also refers to the Salt Museum. The specific name refers to the Honghe river. [1]
The holotype specimen, GCC V20501, had been dug up in a layer of the Lower Shaximiao Formation. It consists of a partial skeleton with skull. Elements of most parts of the body have been preserved, the skull, vertebral column, shoulder girdle, frontlimbs and hindlimbs but all are very limited and/or damaged. The lower jaws, pelvis and the end of the tail had probably been entirely destroyed by the machine. [2]
In 1983 He and Cai Kaiji identified a second species: Yandusaurus multidens, known from two nearly complete skeletons and nine partial skeletons. [3] In 1992 this was by Guangzhao Peng reassigned to the genus Agilisaurus as a A. multidens. In 1996 Gregory S. Paul renamed it as Othnielia multidens. In 2005 it was by Paul Barrett e.a. placed in its own genus, Hexinlusaurus . [4]
A fast-moving biped, Yandusaurus had four toes on each foot and five fingers on each hand. It had large eyes as shown by the curved jugal. The teeth, showing a unique pattern of parallel vertical ridges compared by Chinese researchers to the fingers of the hand of Buddha statues, are very asymmetrical in that the inner side is strongly worn down. The fifteen maxillary teeth are largest in the middle and overlap. [2]
When indicating the size of Yandusaurus many sources give that of Hexinlusaurus, the previous Y. multidens, the (all juvenile) specimens of which are sixty centimetres (two feet) to 1.6 metres (5 ft) in length, and weighed around seven kilograms (fifteen lb). Yandusaurus hongheensis was however considerably larger than these exemplars: He estimated the body length at three metres, [2] Peng at 3.2 metres; in 2010 G.S. Paul gave an estimation of 3.8 metres length and a weight of hundred forty kilogrammes. [5]
Yandusaurus was assigned by He to the Hypsilophodontidae. [1] Today however Hypsilophodontidae is considered an unnatural (paraphyletic) group and Yandusaurus is viewed as taking an unresolved position within Neornithischia. [6] [7]
| |||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||
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.
Yangchuanosaurus is an extinct genus of metriacanthosaurid theropod dinosaur that lived in China from the Middle Jurassic to Late Jurassic periods, and was similar in size and appearance to its North American and European relative, Allosaurus. Yangchuanosaurus hails from the Upper Shaximiao Formation and was the largest predator in a landscape that included the sauropods Mamenchisaurus and Omeisaurus and the stegosaurs Chialingosaurus, Tuojiangosaurus and Chungkingosaurus. This theropod was named after the area in which was discovered, Yongchuan, in China.
Hypsilophodontidae is a traditionally used family of ornithopod dinosaurs, generally considered invalid today. It historically included many small bodied bipedal neornithischian taxa from around the world, and spanning from the Middle Jurassic until the Late Cretaceous. This inclusive status was supported by some phylogenetic analyses from the 1990s and mid 2000s, although there have also been many finding that the family is an unnatural grouping which should only include the type genus, Hypsilophodon, with the other genera being within clades like Thescelosauridae and Elasmaria. A 2014 analysis by Norman recovered a grouping of Hypsilophodon, Rhabdodontidae and Tenontosaurus, which he referred to as Hypsilophodontia. All other analyses from around the same time have instead found these latter taxa to be within Iguanodontia.
Abrosaurus is a genus of macronarian sauropod dinosaur from the Middle Jurassic Period of what is now Asia, one of many dinosaurs found at the Dashanpu Quarry in the Sichuan Province of China. Like most sauropods, Abrosaurus was a quadrupedal herbivore but it was rather small for a sauropod, not much more than 30 feet (9.1 m) long. Its head was boxy and topped with a tall bony arch containing the nostrils.
Xiaosaurus, is a genus of small herbivorous dinosaur from the middle Jurassic, approximately 170.3 to 163.5 mya. Xiaosaurus lived in what is now the Sichuan Basin of China.
Agilisaurus is a genus of ornithischian dinosaur from the Middle Jurassic Period of what is now eastern Asia. It was about 3.5–4 ft long, 2 ft in height and 40 kg in weight.
Shunosaurus, meaning "Lizard from Sichuan", is a genus of sauropod dinosaur from Late Jurassic (Oxfordian) beds in Sichuan Province in China, from 161 to 157 Million years ago. The name derives from "Shu", an ancient name for the Sichuan province.
Huayangosaurus is a genus of stegosaurian dinosaur from the Middle Jurassic of China. The name derives from "Huayang" (華陽), an alternate name for Sichuan, and "saurus", meaning "lizard". It lived during the Bathonian to Callovian stages, around 165 million years ago, some 20 million years before its famous relative, Stegosaurus appeared in North America. At only approximately 4 metres (13 ft) long, it was also much smaller than its famous cousin. Found in the Lower Shaximiao Formation, Huayangosaurus shared the local Middle Jurassic landscape with the sauropods Shunosaurus, Datousaurus, Omeisaurus and Protognathosaurus, the ornithopod Xiaosaurus and the carnivorous Gasosaurus.
Zigongosaurus is a genus of sauropod dinosaur from the Middle Jurassic-Late Jurassic-age Shaximiao Formation of Zigong, Sichuan, China. Because of incomplete knowledge of Jurassic Chinese sauropods, it has been hard to interpret, with some sources assigning it to Omeisaurus, some to Mamenchisaurus, and some to its own genus.
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.
Gigantspinosaurus is a genus of herbivorous ornithischian dinosaur from the Late Jurassic. It was a stegosaur found in China.
Hexinlusaurus is a genus of basal ornithischian dinosaur from the Middle Jurassic of China.
Gongbusaurus is a genus of ornithischian, perhaps ornithopod, dinosaur that lived between about 160 and 157 million years ago, in the Late Jurassic period. A small herbivore, it is very poorly known. Two species have been assigned to it, but as the original name is based on teeth, there is no concrete evidence to connect the two species. Its fossils have been found in China.
Gongxianosaurus is a genus of basal sauropod dinosaur from the early Jurassic Period. The only species is Gongxianosaurus shibeiensis. Based on four fragmentary to complete specimens found in China, it is one of the most completely known early sauropods. The skeleton is known in large part, missing both the hand and the majority of the skull. Gongxianosaurus was firstly named and described in a short note published in 1998; however, a comprehensive description has yet to be published. Gongxianosaurus shibeiensis was named for the place it was found, near the village Shibei in Gong County.
Heterodontosauridae is a family of ornithischian dinosaurs that were likely among the most basal (primitive) members of the group. Their phylogenetic placement is uncertain but they are most commonly found to be primitive, outside of the group Genasauria. Although their fossils are relatively rare and their group small in numbers, they have been found on all continents except Australia and Antarctica, with a range spanning the Early Jurassic to the Early Cretaceous.
Dashanpusaurus is an extinct genus of sauropod dinosaur that lived during the middle of the Jurassic period. The dinosaur was described in 2005 by Peng Guangzhao, Ye Yong, Gao Yuhui, Shu Chunkang, and Jiang Shan. Its type and only species is Dashanpusaurus dongi, named in honor of the paleontologist Dong Zhiming.
Angustinaripterus was a basal pterosaur, belonging to the breviquartossan family Rhamphorhynchidae and discovered at Dashanpu near Zigong in the Sichuan province of China.
Camarasauridae is a family of sauropod dinosaurs. Among sauropods, camarasaurids are small to medium-sized, with relatively short necks. They are visually identifiable by a short skull with large nares, and broad, spatulate teeth filling a thick jaw. Based on cervical vertebrae and cervical rib biomechanics, camarasaurids most likely moved their necks in a vertical, rather than horizontal, sweeping motion, in contrast to most diplodocids.
Hsisosuchus is an extinct genus of crocodyliform from China. Currently there are three species within this genus: H. dashanpuensis is from the Middle Jurassic, while H. chungkingensis and H. chowi are from the Late Jurassic. It is likely to have been a medium-sized predator.
