Poposauroidea

Arizonasaurus (meaning "Arizona reptile") is a genus of ctenosauriscid archosaur from the Middle Triassic (243 million years ago) Moenkopi Formation of what is now Arizona. It is known for having a large back sail formed by elongated neural spines of its vertebrae. The type and only known species is A. babbitti, named and described in 1947.

Poposaurus is an extinct genus of pseudosuchian archosaur from the Late Triassic of the southwestern and eastern United States. It belongs to the clade Poposauroidea, an unusual group of Triassic pseudosuchians that includes sail-backed, beaked, and aquatic forms. Fossils have been found in Wyoming, Utah, Arizona, Texas, and Virginia. Except for the skull, most parts of the skeleton are known. The type species, P. gracilis, was described and named by Maurice Goldsmith Mehl in 1915. A second species, P. langstoni, was originally the type species of the genus Lythrosuchus. Since it was first des

Shuvosaurus (meaning "Shuvo [Chatterjee]'s lizard") is a genus of beaked, bipedal poposauroid pseudosuchian from the Late Triassic (early to middle Norian) of western Texas. Despite superficially resembling a theropod dinosaur, especially the ostrich-like ornithomimids, it is instead more closely related to living crocodilians than to dinosaurs. Shuvosaurus is known by the type and only species S. inexpectatus, and is closely related to the very similar Effigia within the clade Shuvosauridae. Shuvosaurus was originally described from a restored skull and very few fragmentary postcranial bones

Effigia is an extinct genus of shuvosaurid known from the Late Triassic of New Mexico, south-western USA. With a bipedal stance, long neck, and a toothless beaked skull, Effigia and other shuvosaurids bore a resemblance to the ornithomimid dinosaurs of the Cretaceous Period. However, shuvosaurids were not dinosaurs, but were instead a specialized family of poposauroid pseudosuchians, meaning that their closest living relatives are crocodilians.

Poposauridae is a family of large carnivorous archosaurs which lived alongside dinosaurs during the Late Triassic. They were around long. Poposaurids are known from fossil remains from North and South America. While originally believed to be theropod dinosaurs (they mirrored the theropods in a number of respects, such as features of the skull and bipedal locomotion), cladistic analysis has shown them to be more closely related to crocodiles.

Ctenosauriscidae is an extinct family of pseudosuchian archosaurs within the clade Poposauroidea. Ctenosauriscids existed in Africa, Asia, Europe and North America during the Early Triassic to the Middle Triassic period (latest Olenekian to Anisian stages). All species had large "sails" on their backs. Ctenosauriscids are among some of the earliest archosaurs and represent the first global radiation of the group.

Poposauroidea is a clade of advanced pseudosuchians. It includes poposaurids, shuvosaurids, ctenosauriscids, and other unusual pseudosuchians such as Qianosuchus and Lotosaurus. It excludes most large predatory quadrupedal "rauisuchians" such as rauisuchids and "prestosuchids". Those reptiles are now allied with crocodylomorphs (crocodile ancestors) in a clade known as Loricata, which is the sister taxon to the poposauroids in the clade Paracrocodylomorpha. Although it was first formally defined in 2007, the name "Poposauroidea" has been used for many years. The group has been referred to as P

Sillosuchus is a genus of large (femur length = in the holotype) shuvosaurid poposauroid archosaur that lived in South America during the Late Triassic period. Shuvosaurids were an unusual family of reptiles belonging to the group Poposauroidea; although their closest modern relatives are crocodilians, they were bipedal and lightly armored, with dinosaur-like hip and skull structures. Based on skull remains from members of the family such as Effigia, they were also toothless and likely beaked herbivores.

Qianosuchus is an extinct genus of aquatic poposauroid archosaur from the middle Triassic (Anisian) Guanling Formation of Pan County, China. It is represented by two nearly complete skeletons and a crushed skull preserved in the limestone. Qianosuchus was at least 3 metres long, and had several skeletal adaptations which indicate a semi-marine lifestyle, similar to modern-day saltwater crocodiles. These adaptations have not been seen in any other archosaur from the Triassic.

Ctenosauriscus (meaning "Ctenosaura-like") is an extinct genus of sail-backed poposauroid archosaur from Early Triassic deposits of Lower Saxony in northern Germany. It gives its name to the family Ctenosauriscidae, which includes other sail-backed poposauroids such as Arizonasaurus. Fossils have been found in latest Olenekian deposits around 247.5-247.2 million years old, making it one of the first known archosaurs.

Lotosaurus is an extinct genus of sail-backed poposauroid known from Hunan Province of central China.

Shuvosauridae is an extinct family of theropod-like pseudosuchians within the clade Poposauroidea. Shuvosaurids existed in North America (United States) and South America (Argentina) during the Late Triassic period (late Carnian to Rhaetian stages). Shuvosauridae was named by Sankar Chatterjee in 1993 to include the genus Shuvosaurus.

Hypselorhachis is a genus of extinct reptile, possibly a ctenosauriscid archosaur related to Ctenosauriscus. It lived during the Triassic Period. It is currently known only from a single vertebra found from the Middle Triassic Manda Beds in Tanzania. The vertebra is preserved in reasonably good condition, as although the tall neural spine is chipped in several places it is not broken despite being quite slender, only around 20 mm thick transversely.

Xilousuchus is an extinct genus of poposauroid from lower Triassic (Olenekian stage) deposits of Fugu County of northeastern Shanxi Province, China. Xilousuchus is one of the oldest archosaurs known to date.

Bromsgroveia is an extinct genus of predatory ctenosauriscid archosaur from the Middle Triassic Bromsgrove Sandstone of England. Ctenosauriscids were a group of rauisuchians that was related to the ancestors of modern crocodiles and alligators.