Early Cretaceous dinosaurs

Mamenchisaurus ( , or spelling pronunciation ) is an extinct genus of sauropod dinosaurs 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

Psittacosaurus ( ; "parrot lizard") is a genus of extinct ceratopsian dinosaur from the Early Cretaceous of what is now Asia, existing between 125 and 105 million years ago. It is notable for being the most species-rich non-avian dinosaur genus. Up to 13 species are known, from across China, Mongolia, Russia, and Thailand. The species of Psittacosaurus were obligate bipeds at adulthood, with a high skull and a robust beak. One individual was found preserved with long filaments on the tail, similar to those of Tianyulong. Psittacosaurus probably had complex behaviours, based on the proportions

Pachycephalosauria (; from Greek παχυκεφαλόσαυρος for 'thick headed lizards') is a clade of ornithischian dinosaurs. Along with Ceratopsia, it makes up the clade Marginocephalia. Pachycephalosaurs lived exclusively in the Northern Hemisphere during the Cretaceous period, with all members being found in North America and Asia. They were all bipedal, herbivorous/omnivorous animals with thick skulls. Skulls can be domed, flat, or wedge-shaped depending on the species, and are all heavily ossified. The domes were often surrounded by nodes and/or spikes. Partial skeletons have been found of several

Siamosaurus (meaning "Siam lizard") is a potentially dubious genus of spinosaurid dinosaur that lived in what is now Thailand and possibly China during the Early Cretaceous period (Barremian to Aptian) and is the first reported spinosaurid from Asia. It is confidently known only from tooth fossils; the first were found in the Sao Khua Formation, with more teeth later recovered from the younger Khok Kruat Formation. The only species Siamosaurus suteethorni, whose name honours Thai palaeontologist Varavudh Suteethorn, was formally described in 1986. In 2009, four teeth from China previously attr

Siamotyrannus (meaning "Siamese tyrant") is a genus of possibly allosauroid theropod dinosaur from the Early Cretaceous Sao Khua Formation of Thailand.

Tangvayosaurus (meaning "Tang Vay lizard") is a genus of sauropod dinosaur from the Lower Cretaceous (Aptian to Albian ages) Grès supérieurs Formation of Savannakhet Province, Laos. It was a basal somphospondylan, measuring about long, and is known from the remains of two or three individuals.

Asiatosaurus (meaning "Asian lizard") is an extinct genus of herbivorous sauropod dinosaur which lived during the Early Cretaceous in Mongolia and China. The type species is known only from teeth, making it difficult to rely on information until more specimens are found to expand our knowledge, and another species is known, also based on scant remains; both are now classified as nomina dubia. This genus was classified within Brachiosauridae by Hou et al. in 1975, and considered a euhelopodid by Poropat et al. in 2022.

Valdosaurus ("Weald lizard") is a genus of bipedal herbivorous dryosaurid dinosaur known from the Early Cretaceous of the Isle of Wight and elsewhere in England. Originally its remains were believed to belong to Hypsilophodon. In 1889, Richard Lydekker assigned them to Camptosaurus, alongside a partial lower jaw, and applied the name Camptosaurus valdensis. In the 1970s, Peter Galton reassigned these remains to a new species of Dryosaurus, then to an entirely new genus and species, that being Valdosaurus proper. The type and only species of Valdosaurus, named by Galton, is V. canaliculatus.

Gobisaurus is an extinct genus of herbivorous basal ankylosaurid ankylosaur from the Lower Cretaceous of China (Nei Mongol Zizhiqu). The genus is monotypic, containing only the species Gobisaurus domoculus.

REDIRECT Iguanodon

Baryonychinae is an extinct clade or subfamily of spinosaurids from the Early Cretaceous of Europe and West Africa. The clade was named by Charig & Milner in 1986 and defined by Sereno et al. in 1998 and Holtz et al. in 2004 as all taxa both closely related to Baryonyx walkeri and Spinosaurus aegyptiacus.

Microraptoria (Greek, μίκρος, mīkros: "small"; Latin, raptor: "one who seizes") is a clade of basal dromaeosaurid theropod dinosaurs. Definitive microraptorians lived during the Barremian to Aptian stages of the Early Cretaceous in China. Probable microraptorian ichnotaxon Dromaeosauriformipes was discovered from the Jinju Formation of South Korea, and some fragmentary Late Cretaceous paravian fossils in North America have been described as putative members of this clade. Many are known for long feathers on their legs and may have been semiarboreal powered fliers, some of which were even capab

Polacanthinae is a subfamily of ankylosaurs, most often nodosaurids, from the Late Jurassic through Early Cretaceous of Europe and potentially North America and Asia. The group is defined as the largest clade closer to Polacanthus foxii than Nodosaurus textilis or Ankylosaurus magniventris, as long as that group nests within either Nodosauridae or Ankylosauridae. If Polacanthus, and by extent Polacanthinae, falls outside either family-level clade, then the -inae suffix would be inappropriate, and the proper name for the group would be the informally defined Polacanthidae.

Jiutaisaurus (meaning "Jiutai lizard") is a genus of sauropod dinosaur from the Quantou Formation of Jilin, China. The formation dates from the Early - Late Cretaceous boundary. The type species, Jiutaisaurus xidiensis, was described by Wu et al. in 2006, and is based on eighteen vertebrae. It probably lived alongside Changchunsaurus and Helioceratops.

Galleonosaurus (meaning "galleon lizard" as the upper jaw bone resembles an upturned galleon) is a genus of basal ornithopod dinosaur from the Wonthaggi Formation of the Gippsland region of Victoria, Australia. The type and only species is Galleonosaurus dorisae.

Fusuisaurus (meaning "Fusui lizard" from the name of the county where it was discovered) is a genus of sauropod dinosaur from the Early Cretaceous of China. Fragmentary postcranial remains of this animal have been discovered in 2001 in the Xinlong Formation of Guangxi, and consist of the left ilium, left pubis, anterior caudals, most of the dorsal ribs, and distal end of the left femur. This sauropod has been described as a basal titanosauriform. The type species is F. zhaoi, named in honour of Chinese paleontologist Zhao Xijin.

Napaisaurus is a genus of iguanodontian ornithopod dinosaur from the Early Cretaceous Xinlong Formation of Guangxi, China. The type and only species is N. guangxiensis.

Stegosaurides (meaning "Stegosaurus-shaped") is a genus of herbivorous thyreophoran (perhaps ankylosaurid or possibly stegosaurian) dinosaur. It lived during the Cretaceous. Its fossils were found in the Xinminbao Group near Heishan in Gansu Province in China. These fossils consist of fragmentary material, including dermal spine elements. The genus is occasionally misspelled as "Stegosauroides".

Udelartitan is an extinct genus of saltasauroid titanosaurian sauropod dinosaur from the Late Cretaceous Guichón Formation of Uruguay. The genus contains a single species, U. celeste, known from fragmentary remains of at least two individuals.

Triunfosaurus (meaning "Triunfo Basin reptile") is a genus of somphospondylan sauropod dinosaur from the Early Cretaceous of Brazil. It contains a single species, T. leonardii, described by Carvalho et al. in 2017. As a genus, Triunfosaurus can be distinguished from all other titanosaurs by the unique proportions of its ischium. It was initially described as a basal titanosaur, making it the earliest basal titanosaur known; however, subsequent research questioned the identification of the taxon as a titanosaur, instead reassigning it to the Somphospondyli.