The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years ago (Mya) to the beginning of the Cretaceous Period, approximately 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified.
Sauropterygia is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic. Sauropterygians are united by a radical adaptation of their pectoral girdle, adapted to support powerful flipper strokes. Some later sauropterygians, such as the pliosaurs, developed a similar mechanism in their pelvis.
Asian box turtles are turtles of the genus Cuora in the family Geoemydidae. About 12 extant species are recognized. The keeled box turtle is often included in this genus, or separated in the monotypic genus Pyxidea. Genus Cuora is distributed from China to Indonesia and the Philippines, throughout mainland Southeast Asia, and into northern India and Bhutan.
Metriacanthosauridae is an extinct family of allosauroid theropod dinosaurs that lived from the Middle Jurassic to the Early Cretaceous. When broken down into its Greek roots, it means "moderately-spined lizards". The family is split into two subgroups: Metriacanthosaurinae, which includes dinosaurs closely related to Metriacanthosaurus, and another group composed of the close relatives of Yangchuanosaurus. Metriacanthosaurids are considered carnosaurs, belonging to the Allosauroidea superfamily. The group includes species of large range in body size. Of their physical traits, most notable are their neural spines. The records of the group are mostly confined to Asia, though Metriacanthosaurus is known from Europe. Metriacanthosauridae is used as a senior synonym of Sinraptoridae.
Trionychia is a superfamily of turtles which encompasses the species that are commonly referred to as softshelled turtles as well as some others. The group contains two families, Carettochelyidae, which has only one living species, the pig-nosed turtle native to New Guinea and Northern Australia, and Trionychidae, the softshelled turtles, containing numerous species native to Asia, North America and Africa. These families likely diverged during the late Jurassic. The oldest known stem-trionychian is Sinaspideretes from the Late Jurassic of China.
The Shaximiao Formation is a Middle to Late Jurassic aged geological formation in Sichuan, China, most notable for the wealth of dinosaurs fossils that have been excavated from its strata. The Shaximiao Formation is exposed in and around the small township of Dashanpu, situated seven kilometres north-east from Sichuan's third largest city, Zigong, in the Da'an District.
Paracryptodira is an extinct group of reptiles in the clade Testudinata, known from the Jurassic to Paleogene of North America and Europe. Initially treated as a suborder sister to Cryptodira, they were then thought to be a very primitive lineage inside the Cryptodira according to the most common use of the latter taxon. They are now often regarded as late-diverging stem-turtles, lying outside the clade formed by Cryptodira and Pleurodira. The paracryptodires are said to have phylogenic relationships, noted as primary subclades, within the Baenidae and Pleurosternidae. Within each subclade, lies many biodiverse turtles that are continuously being investigated and added to the fossil record. Paracryptodires are divided into three main groups, Compsemydidae, known from the Late Jurassic to Paleocene of North America and Europe, Pleurosternidae, known from the Late Jurassic to Early Cretaceous of North America and Europe, and Baenidae, known from the Early Cretaceous to Eocene of North America. The latter two groups are more closely related to each other than to Compsemys, forming the clade Baenoidea.
Sinaspideretes is an extinct genus of turtle from the Late Jurassic of China, probably from the Shaximiao Formation. It is considered the earliest and most basal representative of the Trionychia, and is possibly the oldest known member of Cryptodira. In 2013, it was proposed that this animal and the genus Yehguia are in fact one and the same.
Ctenochasmatidae is a group of pterosaurs within the suborder Pterodactyloidea. They are characterized by their distinctive teeth, which are thought to have been used for filter-feeding. Ctenochasmatids lived from the Late Jurassic to the Early Cretaceous periods.
Protochelydra zangerli is an extinct species of chelydid in the extinct genus Protochelydra of Chelydridae.
The Early Cretaceous Phu Kradung Formation is the lowest member of the Mesozoic Khorat Group which outcrops on the Khorat Plateau in Isan, Thailand. This geological formation consists of micaceous, brown to reddish-brown siltstone beds with minor brown and grey shale and sandstone beds. Occasional lime-noduled conglomerate occurs.
The Qigu Formation is a Late Jurassic (Oxfordian) geologic formation in the Southern Junggar Basin in China. Indeterminate Dinosaur remains are among the fossils that have been recovered from the formation, including theropod teeth and a fibula. a stegosaur dorsal vertebra and a Eusauropod tooth. Xinjiangtitan was erroneously thought to be from this formation, but it is actually from the older Qiketai Formation, which is in a different basin. The term "Qigu Formation" is also used to sediments of equivalent age in the Turpan Basin, but this might better be treated as a separate formation. It is laterally equivalent to the Shishugou Formation.
Sunosuchus is an extinct genus of goniopholidid mesoeucrocodylian. Fossils are known from China, Kyrgyzstan, and Thailand and are Jurassic in age, although some may be Early Cretaceous. Four species are currently assigned to the genus: the type species S. miaoi and the species S. junggarensis, S. shartegensis, and S. shunanensis. All species are from China. Goniopholis phuwiangensis, also from Thailand, was reassigned to Sunosuchus by Andrade et al. (2011). The material from Kyrgyzstan has not been assigned to any species.
Bashuchelys is an extinct genus of bashuchelyid Middle Jurassic turtle from the Sichuan Basin in the People's Republic of China. As of 2011, it is the only known genus of the family Bashuchelyidae.
Protoxinjiangchelys is an extinct genus of xinjiangchelyid turtle known from the Early to Late Jurassic of China. It is known from the single species P. salis, which was named and described in 2012. It contains only the holotype, ZDM 3009, which consists of a complete shell with an articulated carapace and a complete plastron and possibly another, older specimen.
Larachelus is an extinct genus of xinjiangchelyid turtle known from the Early Cretaceous of Spain.
Sichuanchelyidae is a family of extinct turtles in the clade Testudinata. It includes all perichelydians that are more closely related to Sichuanchelys than Meiolania, Helochelydra, or any extant turtles.
Xinjiangchelyidae is an extinct family of turtles known from the Lower Jurassic to the Middle Cretaceous of Asia and western Europe. They have generally been interpreted as either being basal cryptodires or placed outside of crown Testudines.
The Xintiangou Formation is a geological formation in China. Part of the stratigraphy of the Sichuan Basin, it is of an uncertain Middle Jurassic age, with preliminary U-Pb estimates giving an age range of 170 ma. It predominantly consists of interbedded mudstone and sandstone, with subordinate shelly limestone. At the Laojun site remains of lungfish, bony fish, freshwater sharks, temnospondyls, plesiosaurs, crocodyliformes, the Xinjiangchelyid turtle Protoxinjiangchelys and tritylodontids are known. The dinosaurs Sanxiasaurus,Yunyangosaurus, and indeterminate sauropods are also known from the formation. Theropod and ornithopod tracks have also been reported from the formation.
Mesochelydia is a clade within Pantestudines, more inclusive than Perichelydia, but less than Testudinata. The clade is known from the Early Jurassic to the Present, and contains all Jurassic representatives of Testudinata aside from Australochelys. The ancestral condition for Mesochelydia is thought to be aquatic, as opposed to terrestrial for Testudinata. They are distinguished from more basal testudinatans by the presence of the following characters: strap like pectoral girdle, supramarginals absent, reduced posterior entoplastral process, eleven pairs of peripherals, elongate processus interfenestralis, paired basioccipital tubercles, fully formed cavum tympani and antrum postoticum, single vomer, confluent external nares, lacrimals and supratemporals absent.
