Chialingosaurus (meaning "Chialing Lizard") is a genus of herbivorous stegosauriandinosaur similar to Kentrosaurus from the Upper Shaximiao Formation, Late Jurassic beds in Sichuan Province in China. Its age makes it one of the oldest species of stegosaurs, living about 160 million years ago. Since it was an herbivore, scientists think that Chialingosaurus probably ate ferns and cycads, which were plentiful during the period when Chialingosaurus was alive.
The fossils of Chialingosaurus were collected by the geologist Kuan Yaowu or Guan Yao-Wu in 1957, at Taipingstai in Quxian County, while surveying the Chialing River in southern China. The type speciesChialingosaurus kuani was named and described by paleontologist Yang Zhongjian, ("C. C. Young") two years later in 1959. The generic name refers to the Chialing. The specific name honours Kuan. Chialingosaurus was the first stegosaurian described from China.[1]
The holotype, IVPP 2300, was found in a layer of the Upper Shaximiao Formation, dating from the Oxfordian-Kimmeridgian. It consists of a partial skeleton lacking the skull. It contains six vertebrae, the coracoids, the humeri, a right radius and three spines. The original material has been supplemented after November 1978 by Zhou Shiwu of the Municipal Museum of Chongqing. A second specimen, CV 202, was referred. It represents a skeleton with a partial skull and lower jaws, some vertebrae and limb elements, and four plates. Zhou considered it likely that the holotype and CV 202 represented a single individual, as the material was not overlapping. A third specimen, CV 203, a partial skeleton lacking the skull, was made the paratype. All specimens are juvenile or subadult.[2]
In 1999, Li Kui, Zhang Yuguang and Cai Kaiji mentioned a second species: Chialingosaurus guangyuanensis.[3] A description was not provided, however, and the name is seen as a nomen nudum.
Yang in 1959 provided a diagnosis, emphasising the slender build of the animal.[1] It might have been only four metres (thirteen feet) long. However, the gracile proportions may have been caused by the subadult age and the remainder of the diagnostic traits were in fact shared by other stegosaurs. In 1990, Peter Malcolm Galton identified just a single autapomorphy: the lesser trochanter of the thighbone is triangular with a broad base.[4]Susannah Maidment in 2008 even listed Chialingosaurus kuani among the invalid stegosaur taxa in her phylogeny of Stegosauria.[5] This was based upon previous work by Maidment & Wei in 2006 in which the authors were unable to identify any autapomorphies or unique character combinations for Chialingosaurus, therefore making it a nomen dubium.[2] Yang modelled Chialingosaurus after Kentrosaurus. Some plates and spine bases having been found, he suggested that the plates were placed on the front upper parts of the animal, the spines at the hip and tail.[1]
Phylogeny
Yang in 1959 placed Chialingosaurus in the Stegosaurinae within the Stegosauridae.[1] In 1969, Rodney Steel suggested that Chialingosaurus might have actually been an early ancestor of other stegosaurs.[6] However, Galton in 2004 recovered a rather derived position, albeit indeed close to Kentrosaurus.[7] Dong confirmed the placement in the Stegosaurinae.
↑ Li Kui, Zhang Yuguang & Cai Kaiji. 1999. The Characteristics of the Composition of the Trace Elements in Jurassic Dinosaur Bones and Red Beds in Sichuan Basin. Geological Publishing House, Beijing
↑ Galton, P.M., 1990, "Stegosauria", in: D.B. Weishampel, P. Dodson, & H. Osmólska (eds.), The Dinosauria. University of California Press, pp. 435-455
↑ Susannah C. R. Maidment, David B. Norman, Paul M. Barrett and Paul Upchurch (2008). "Systematics and phylogeny of Stegosauria (Dinosauria: Ornithischia)". Journal of Systematic Palaeontology, 6: 367-407 doi:10.1017/S1477201908002459
↑ Steel, R., 1969, Ornithischia. Handbuch der Palaeoherpetologie, 14
↑ Galton, P.M., and P. Upchurch, 2004, "Stegosauria", pp. 343-362 in: D.B. Weishampel, P. Dodson, and H. Osmolska (eds.), The Dinosauria, 2nd Edition. University of California Press, Berkeley, CA
Stegosaurus is a genus of herbivorous, four-legged, armored dinosaur from the Late Jurassic, characterized by the distinctive kite-shaped upright plates along their backs and spikes on their tails. Fossils of the genus have been found in the western United States and in Portugal, where they are found in Kimmeridgian- to Tithonian-aged strata, dating to between 155 and 145 million years ago. Of the species that have been classified in the upper Morrison Formation of the western US, only three are universally recognized: S. stenops, S. ungulatus and S. sulcatus. The remains of over 80 individual animals of this genus have been found. Stegosaurus would have lived alongside dinosaurs such as Apatosaurus, Diplodocus, Camarasaurus and Allosaurus, the latter of which may have preyed on it.
Kentrosaurus is a genus of stegosaurid dinosaur from the Late Jurassic in Lindi Region of Tanzania. The type species is K. aethiopicus, named and described by German palaeontologist Edwin Hennig in 1915. Often thought to be a "primitive" member of the Stegosauria, several recent cladistic analyses find it as more derived than many other stegosaurs, and a close relative of Stegosaurus from the North American Morrison Formation within the Stegosauridae.
Hesperosaurus is a herbivorous stegosaurian dinosaur from the Kimmeridgian age of the Jurassic period, approximately 156 million years ago.
Dacentrurus, originally known as Omosaurus, is a genus of stegosaurian dinosaur from the Late Jurassic to Early Cretaceous of Europe. Its type species, Omosaurus armatus, was named in 1875, based on a skeleton found in a clay pit in the Kimmeridge Clay in Swindon, England. In 1902 the genus was renamed Dacentrurus because the name Omosaurus had already been used for a crocodylian. After 1875, half a dozen other species would be named but perhaps only Dacentrurus armatus is valid. Finds of this animal have been limited and much of its appearance is uncertain. It was a heavily built quadrupedal herbivore, adorned with plates and spikes, reaching 8–9 metres (26–30 ft) in length and 5 metric tons in body mass.
Dravidosaurus is a controversial taxon of Late Cretaceous reptiles, variously interpreted as either a ornithischian, possibly stegosaurian, dinosaur or a plesiosaur. The genus contains a single species, D. blanfordi, known from mostly poorly preserved fossils from the Coniacian of southern India.
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Lexovisaurus is a genus of stegosaur from mid-to-Late Jurassic Europe, 165.7-164.7 mya. Fossils of limb bones and armor fragments have been found in middle to late Jurassic-aged strata of England and France.
Tuojiangosaurus is a genus of herbivorous stegosaurian dinosaur from the Late Jurassic Period, recovered from the Upper Shaximiao Formation of what is now Sichuan Province in China.
Paranthodon is a genus of stegosaurian dinosaur that lived in what is now South Africa during the Early Cretaceous, between 139 and 131 million years ago. Discovered in 1845, it was one of the first stegosaurians found. Its only remains, a partial skull, isolated teeth, and fragments of vertebrae, were found in the Kirkwood Formation. British paleontologist Richard Owen initially identified the fragments as those of the pareiasaur Anthodon. After remaining untouched for years in the British Museum of Natural History, the partial skull was identified by South African paleontologist Robert Broom as belonging to a different genus; he named the specimen Palaeoscincus africanus. Several years later, Hungarian paleontologist Franz Nopcsa, unaware of Broom's new name, similarly concluded that it represented a new taxon, and named it Paranthodon owenii. Since Nopcsa's species name was assigned after Broom's, and Broom did not assign a new genus, both names are now synonyms of the current binomial, Paranthodon africanus. The genus name combines the Ancient Greek para (near) with the genus name Anthodon, to represent the initial referral of the remains.
Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere, predominantly in what is now North America, Europe, Africa, South America and Asia. Their geographical origins are unclear; the earliest unequivocal stegosaurian, Huayangosaurus taibaii, lived in China.
Stegosauridae is a family of thyreophoran dinosaurs within the suborder Stegosauria. The clade is defined as all species of dinosaurs more closely related to Stegosaurus than Huayangosaurus. The name ‘Stegosauridae’ is thus a stem-based name taken from the well-represented genus – Stegosaurus. Fossil evidence of stegosaurids, dating from the Middle Jurassic through the Early Cretaceous, have been recovered from North America, Eurasia and Africa.
Huayangosauridae is a family of stegosaurian dinosaurs from the Jurassic of China. The group is defined as all taxa closer to the namesake genus Huayangosaurus than Stegosaurus, and was originally named as the family Huayangosaurinae by Dong Zhiming and colleagues in the description of Huayangosaurus. Huayangosaurinae was originally differentiated by the remaining taxa within Stegosauridae by the presence of teeth in the premaxilla, an antorbital fenestra, and a mandibular fenestra. Huayangosaurinae, known from the Middle Jurassic of the Shaximiao Formation, was proposed to be intermediate between Scelidosaurinae and Stegosaurinae, suggesting that the origins of stegosaurs lay in Asia. Following phylogenetic analyses, Huayangosauridae was expanded to also include the taxon Chungkingosaurus, known from specimens from younger Late Jurassic deposits of the Shaximiao Formation. Huayangosauridae is either the sister taxon to all other stegosaurs, or close to the origin of the clade, with taxa like Gigantspinosaurus or Isaberrysaura outside the Stegosauridae-Huayangosauridae split. Huayangosauridae was formally defined in 2021 by Daniel Madzia and colleagues, who used the previous definitions of all taxa closer to Huayangosaurus taibaii than Stegosaurus stenops, and chose the 2020 phylogeny of Susannah Maidment et al. to illustrate the relationships of the clade:
Chungkingosaurus, meaning "Chongqing Lizard", is a genus of herbivorous dinosaur from the Late Jurassic Upper Shaximiao Formation in what is now China. It is a member of the Stegosauria.
Gigantspinosaurus is a genus of herbivorous ornithischian dinosaur from the Late Jurassic. It was a stegosaur found in China.
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This timeline of stegosaur research is a chronological listing of events in the history of paleontology focused on the stegosaurs, the iconic plate-backed, spike-tailed herbivorous eurypod dinosaurs that predominated during the Jurassic period. The first scientifically documented stegosaur remains were recovered from Early Cretaceous strata in England during the mid-19th century. However, they would not be recognized as a distinct group of dinosaurs until Othniel Charles Marsh described the new genus and species Stegosaurus armatus in 1877, which he regarded as the founding member of the Stegosauria. This new taxon originally included all armored dinosaurs. It was not until 1927 that Alfred Sherwood Romer implemented the modern use of the name Stegosauria as specifically pertaining to the plate-backed and spike-tailed dinosaurs.
Adratiklit is an extinct genus of herbivorous stegosaurian dinosaur that lived on the supercontinent Gondwana during the Middle Jurassic period. The genus contains a single species, Adratiklit boulahfa. Its remains were found in the El Mers Group, probably in the El Mers II Formation (Bathonian), near Boulahfa, south of Boulemane, Fès-Meknes, north Morocco.
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