Omeisaurus (meaning "Omei lizard") is a genus of sauropod dinosaur from the Middle Jurassic Period (Bathonian-Callovian stage) of what is now China. Its name comes from Mount Emei, where it was discovered in the lower Shaximiao Formation of Sichuan Province.
Temporal range: Middle Jurassic, Bathonian–Callovian
|O. tianfuensis on display in Hong Kong|
Omeisaurus was first described in 1939. It was named after the sacred mountain Omeishan, which is where the first fossil example of Omeisaurus was found. Most skeletons of Omeisaurus were found in the 1970s and 1980s, during the great “Chinese dinosaur rush”. There have been seven species of Omeisaurus named so far: O. junghsiensis, O. changshouensis, O. fuxiensis, O. tianfuensis, O. luoquanensis, O. maoianus, and O. jiaoi. All of these but the last two were named after the locations where they were found. O. fuxiensis was the smallest species, measuring around 35 feet (11 m) long. O. tianfuensis had the longest neck of the genus, around 30 feet (9.1 m) long. The only dinosaur with a longer neck was Mamenchisaurus. Tail clubs have in 1988/1989 been referred to Omeisaurus tianfuensis, but Paul Upchurch in 2004 considered them possible Shunosaurus clubs. In their paper on Qijianglong, Xing et al. (2015) considered O. maoianus more closely related to Mamenchisaurus than to O. tianfuensis, a proposal supported by the cladistic analysis of Ren et al. (2018).
It was once classified as a member of the family Cetiosauridae, which had long been a wastebasket taxon. The species O. fuxiensis is sometimes confused with Zigongosaurus, but the two are based on different material despite having the same species name.
Omeisaurus was formerly assigned to Euhelopodidae. However, it and other Jurassic sauropods from Asia formerly assigned to Euhelopodidae are now placed in the separate family Mamenchisauridae.
Omeisaurus lived in dense forests. Different species of Omeisaurus sometimes shared habitats with each other (O. junghsiensis and O. tianfuensis, for example). In addition to other species of Omeisaurus, Shunosaurus and Datousaurus are also known from the Xiashaximiao Formation, while Mamenchisaurus is present in the Shangshaximiao Formation. Yangchuanosaurus is a large theropod from the Shangshaximiao, and it probably preyed on sauropods. The smaller Xuanhanosaurus was also present. In the Xiashaximiao, another theropod, Gasosaurus, was also present, as was the herbivorous stegosaur Huayangosaurus. The latter probably did not compete with sauropods for food.
Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1939.Anhuilong
Anhuilong is a genus of mamenchisaurid dinosaur found in the Anhui province of China. It contains a single species, Anhuilong diboensis. Ren et al. (2018) recover Anhuilong as the sister taxon of Huangshanlong, with the closest relative to this clade being Omeisaurus tianfuensis.Dashanpu Formation
The Dashanpu Formation is a Mid to Late Jurassic rock formation in China, most notable for the wealth of dinosaurs that have been excavated from the area. The Dashanpu Formation sits in and around the small township of Dashanpu (simplified Chinese: 大山铺镇; traditional Chinese: 大山鋪鎮; pinyin: Dàshānpū zhèn), situated seven kilometres north-east from Sichuan's third largest city, Zigong, in the Da'an District.Datousaurus
Datousaurus, meaning "Big-head Lizard" (from the Chinese da tou "Big Head" and Greek sauros/σαυρος "lizard") was a dinosaur from the Middle Jurassic. It was a sauropod collected from the Lower Shaximiao Formation in Dashanpu, Zigong Sichuan province, China. It shared the local Middle Jurassic landscape with other sauropods such as Shunosaurus, Omeisaurus, Protognathosaurus, the ornithopod Xiaosaurus, the early stegosaur Huayangosaurus as well as the carnivorous Gasosaurus.Dong Zhiming
Dong Zhiming (Chinese: 董枝明, Pinyin: Dǒng Zhimíng; born January 1937), of the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing, is a Chinese vertebrate paleontologist. He began working at the IVPP in 1962, studying under Yang Zhongjian, who was director at the time. He has described fossil remains of many dinosaurs, including sauropods such as Shunosaurus, Datousaurus and Omeisaurus, as well as Archaeoceratops. He investigated and described the Dashanpu Formations; an important contribution to science since they are composed of Middle Jurassic beds which do not commonly yield fossils.Euhelopodidae
Euhelopodidae is a family of sauropod dinosaurs which includes the genus Euhelopus. All known euhelopodids lived in what is now East Asia. The family name was first proposed by American paleontologist Alfred Sherwood Romer in 1956. The four genera Chiayusaurus, Omeisaurus, Tienshanosaurus, and Euhelopus were the original proposed euhelopodines (subfamily Euhelopodinae). Other genera such as Mamenchisaurus and Shunosaurus were formerly placed within this family, but these are now regarded as more basal sauropods.
Michael D'Emic (2012) formulated the first phylogenetic definition of Euhelopodidae, defining it as the clade containing "neosauropods more closely related to Euhelopus zdanskyi than to Neuquensaurus australis". Below is a cladogram presenting the cladistic hypothesis of Euhelopodidae proposed by D'Emic.Gravisauria
Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda.Huangshanlong
Huangshanlong is a genus of mamenchisaurid dinosaurs native to the Anhui province of China. It contains a single species, Huangshanlong anhuiensis. H. anhuiensis represents, along with Anhuilong and Wannanosaurus, one of three dinosaurs fround in Anhui province.Huayangosaurus
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 (the province where it was discovered), 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 4.5 metres 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. It was found in Huayang in China.Mamenchisauridae
Mamenchisauridae is a family of sauropod dinosaurs known from the Jurassic and Early Cretaceous of Asia and Africa.Nebulasaurus
Nebulasaurus is an extinct genus of basal eusauropod dinosaur known from the early Middle Jurassic Zhanghe Formation (Aalenian or Bajocian stage) of Yunnan Province, China. It is known only from the holotype braincase LDRC-v.d.1. A phylogenetic analysis found Nebulasaurus to be a sister taxon to Spinophorosaurus from the Middle Jurassic of Africa. This discovery is significant paleontologically because it represents a clade of basal eusauropods previously unknown from Asia.Qijianglong
Qijianglong is a genus of herbivorous mamenchisaurid sauropod dinosaur from the Early Cretaceous of China.Shunosaurus
Shunosaurus, meaning "shu lizard", is a genus of sauropod dinosaur from Early Jurassic (Oxfordian) beds in Sichuan Province in China, approximately 159±2 million years ago. The name derives from "Shu", an ancient name for the Sichuan province.Tehuelchesaurus
Tehuelchesaurus (tay-WAYL-chay-SAWR-us) is a genus of dinosaur. It is named in honor of the Tehuelche people, native to the Argentinian province of Chubut, where it was first found.Tonganosaurus
Tonganosaurus (named for the town of Tong'an from where it was found) 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 lived during the early Jurassic period (Pliensbachian - Toarcian, Yimen Formation) in what is now China. 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.Yangchuanosaurus
Yangchuanosaurus is an extinct genus of metriacanthosaurid theropod dinosaur that lived in China during the Bathonian and Callovian stages of the Middle Jurassic, and was similar in size and appearance to its North American and European relative, Allosaurus. It 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. It was named after the area in which was discovered, Yongchuan, in China.Yuanmousaurus
Yuanmousaurus ("Yuanmou lizard") 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. The only and type species was Yuanmousaurus jiangyiensis.Zigong Dinosaur Museum
The Zigong Dinosaur Museum (simplified Chinese: 自贡恐龙博物馆; traditional Chinese: 自貢恐龍博物館; pinyin: Zìgòng Kǒnglóng Bówùguǎn) is located near the city of Zigong, Sichuan, China, in the township of Dashanpu. The museum sits on top of a large concentration of a diverse dinosaur assemblage from the Dashanpu Formation. The museum claims the largest number of dinosaur fossils in the world and covers 25,000 square meters with a display area of 3,600 square meters. It attracts up to seven million visitors a year.In 1980s, vast quantities of dinosaur fossils were excavated in the Middle Jurassic Dashanpu Formation, 7 km north-east from downtown Zigong, including a dinosaur named after the township, Dashanpusaurus. Because of the unique and articulated (intact) bone remains, Zigong is important to paleontologists and dinosaur enthusiasts. The Zigong Dinosaur Museum was established in 1987, becoming the first museum based almost entirely on dinosaurs in Asia. Mounted specimens include Omeisaurus, Gigantspinosaurus, Yangchuanosaurus, Huayangosaurus and Xiaosaurus.Zigongosaurus
Zigongosaurus (meaning "Zigong lizard") 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.