Changchunsaurus Temporal range: Early-Late Cretaceous, | |
---|---|
Life reconstruction of Changchunsaurus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | † Ornithischia |
Clade: | † Neornithischia |
Family: | † Thescelosauridae |
Genus: | † Changchunsaurus Zan et al., 2005 |
Species: | †C. parvus |
Binomial name | |
†Changchunsaurus parvus Zan et al., 2005 | |
Changchunsaurus (meaning "Changchun lizard") is an extinct genus of small herbivorous dinosaur from Early Cretaceous deposits of Gongzhuling, Jilin, China. It is the first named dinosaur genus from Jilin. [1]
Changchunsaurus was first named by Zan Shu-Qin, Chen Jun, Jin Li-Yong and Li Tao in 2005. The type and only known species is C. parvus ("parvus" meaning "petite"), named for its small size. It is known from a skull and skeleton and additional skull fragments. All specimens of Changchunsaurus were collected from the Quantou Formation of the Songliao Basin, dating to the Aptian–Cenomanian stages. Changchunsaurus is based on the holotype JLUM L0403-j–Zn2, a skeleton and skull, with a premaxilla (upper beak) and partial lower jaw also known. Only the skull was figured and described in the official description. [1]
According to Zan et al. 2005, who described it, the animal shows a combination of features like those of derived ornithopods (reduction in size or loss of some skull fenestrae or holes), and features like those of more basal ornithopods (for example, five teeth in each premaxilla, short toothless portion of upper beak, and a small gap between beak teeth and cheek teeth). There is a projection that sticks out from the side of the jugal or cheekbone, with what is described as a "nubble structure". The type individual was a small animal, around 1 meter long (3.3 feet, with a skull 11.5 centimeters long (4.5 inches). It was originally classified as a basal ornithopod, family unknown, although it was not included in a formal phylogenetic analysis. [1]
Later, some referred specimens were described and in 2010 its cranial anatomy was revised. [2]
In Butler et al., 2011, the postcranial osteology was described for the first time and a large phylogenetic analysis confirmed its position as a basal ornithopod which was found to be closely related to another Chinese ornithopod, Jeholosaurus [3] and later to the newly described Mongolian ornithopod Haya . [4] Han et al. named this clade "Jeholosauridae" in 2012. [5]
The following cladogram was based on analysis by Makovicky et al., 2011. [4]
Archaeoceratops, meaning "ancient horned face", is a genus of basal neoceratopsian dinosaur from the Early Cretaceous of north central China. It appears to have been bipedal and quite small, reaching 0.9 m (3.0 ft) in length and 10 kg (22 lb) in body mass. It had a comparatively large head but no horns, possessing only a small bony frill projecting from the back of its head.
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.
Micropachycephalosaurus is an extinct genus of basal marginocephalian dinosaur containing only the type species, Micropachycephalosaurus hongtuyanensis. It lived in China during the Late Cretaceous (Campanian) and was found in the Jiangjunding Formation.
Tenontosaurus is a genus of iguanodontian ornithopod dinosaur. It had an unusually long, broad tail, which like its back was stiffened with a network of bony tendons.
Stenopelix is a genus of small marginocephalian dinosaur, possibly a basal ceratopsian, from the Early Cretaceous of Germany. It lived in the late Berriasian Stage of the Cretaceous period, approximately 140 myr ago. The genus is based on a partial skeleton lacking the skull, and its classification is based on characteristics of the hips.
Charonosaurus is a genus of dinosaur whose fossils were discovered by Godefroit, Zan & Jin in 2000, on the south bank of the Amur River, dividing China from Russia. It is monotypic, consisting of the species C. jiayinensis.
Neornithischia is a clade of the dinosaur order Ornithischia. It is the sister group of the Thyreophora within the clade Genasauria. Neornithischians are united by having a thicker layer of asymmetrical enamel on the inside of their lower teeth. The teeth wore unevenly with chewing and developed sharp ridges that allowed neornithischians to break down tougher plant food than other dinosaurs. Neornithischians include a variety of basal forms historically known as "hypsilophodonts", including the Parksosauridae; in addition, there are derived forms classified in the groups Marginocephalia and Ornithopoda. The former includes clades Pachycephalosauria and Ceratopsia, while the latter typically includes Hypsilophodon and the more derived Iguanodontia.
Jeholosaurus is a genus of neornithischian dinosaur from the Early Cretaceous Period. It is thought to have been a herbivorous small ornithopod.
Lycorhinus is a genus of heterodontosaurid ornithischian dinosaur from the Early Jurassic strata of the Elliot Formation located in the Cape Province, South Africa.
Tianyulong is an extinct genus of heterodontosaurid ornithischian dinosaur. The only species is T. confuciusi, whose remains were discovered in Jianchang County, Western Liaoning Province, China.
Helioceratops is a genus of herbivorous neoceratopsian dinosaur from the Middle Cretaceous of China.
Fruitadens is a genus of heterodontosaurid dinosaur. The name means "Fruita teeth", in reference to Fruita, Colorado (USA), where its fossils were first found. It is known from partial skulls and skeletons from at least four individuals of differing biological ages, found in Tithonian rocks of the Morrison Formation in Colorado. Fruitadens is one of the smallest known ornithischian dinosaur, with young adults estimated at 65 to 75 cm in length and 0.5 to 0.75 kg in weight. It is interpreted as an omnivore and represents one of the latest-surviving heterodontosaurids.
Koreanosaurus is a genus of orodromine neornithischian dinosaur. One species has been described, Koreanosaurus boseongensis.
Dictyoolithus is an oogenus of dinosaur egg from the Cretaceous of China. It is notable for having over five superimposed layers of eggshell units. Possibly, it was laid by megalosauroid dinosaurs.
Haya is an extinct genus of basal neornithischian dinosaur known from Mongolia.
Yueosaurus is an extinct genus of basal neornithischian dinosaur known from Zhejiang Province, China.
Hexing is an extinct genus of basal ornithomimosaur dinosaur known from the Early Cretaceous of northeastern China. It contains a single species, Hexing qingyi.
Jeholosauridae was a group of herbivorous neornithischian dinosaurs from the Cretaceous Period. The family was first proposed by Han et al. in 2012. The jeholosaurids were defined as all neornithischians more closely related to Jeholosaurus shangyuanensis than to Hypsilophodon foxii, Iguanodon bernissartensis, Protoceratops andrewsi, Pachycephalosaurus wyomingensis, or Thescelosaurus neglectus. The Jeholosauridae includes the type genus Jeholosaurus, and also possibly Yueosaurus, Changchunsaurus, and Haya.