Huayangosauridae (derived from ''

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 ...

'', "

Huayang Guo Zhi The ''Chronicles of Huayang'' or ''Huayang Guo Zhi'' () is the oldest extant gazetteer of a region of China. It was compiled by Chang Qu during the Jin Dynasty. It contains roughly 110,000 characters. Its contents comprise history, geography and ...

reptile") is a family of

stegosauria 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, Europ ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s from the

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

. The group is defined as all taxa closer to the namesake genus ''Huayangosaurus'' than ''

Stegosaurus ''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 fou ...

'', and was originally named as the family Huayangosaurinae by

Zhiming Dong Dong Zhiming (Chinese: 董枝明, Pinyin: ''Dǒng Zhimíng''; born January 1937) is a Chinese vertebrate paleontologist formerly employed at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) in Beijing. He began working at the ...

and colleagues in the description of ''Huayangosaurus''. Huayangosaurinae was originally differentiated by the remaining taxa within Stegosauridae by the presence of

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, ...

in the , an , and a . Huayangosaurinae, known from the

Middle Jurassic The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively ...

of the Shaximiao Formation, was proposed to be intermediate between

Scelidosaurinae Thyreophora ("shield bearers", often known simply as "armored dinosaurs") is a group of armored ornithischian dinosaurs that lived from the Early Jurassic until the end of the Cretaceous. Thyreophorans are characterized by the presence of bo ...

and Stegosaurinae, suggesting that the origins of stegosaurs lay in Asia. Following phylogenetic analyses, Huayangosauridae was expanded to also include the taxon ''

Chungkingosaurus ''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. Description According to Dong e.a. the ''Chungkingo ...

'', 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 File:2021 collage V2.png, From top left, clockwise: the James Webb Space Telescope was launched in 2021; Protesters in Yangon, Myanmar following the coup d'état; A civil demonstration against the October 2021 coup in Sudan; Crowd shortly after t ...

by Daniel Madzia and colleagues, who used the previous definitions of all taxa closer to ''Huayangosaurus taibaii'' than '' Stegosaurus stenops'', and chose the

2020 2020 was heavily defined by the COVID-19 pandemic, which led to global social and economic disruption, mass cancellations and postponements of events, worldwide lockdowns and the largest economic recession since the Great Depression in t ...

phylogeny of Susannah Maidment ''et al.'' to illustrate the relationships of the clade:

References

{{Taxonbar, from=Q3496700 Stegosaurs Jurassic dinosaurs Prehistoric dinosaur families