Dinocephalosaurus is a genus of long necked, aquatic protorosaur that inhabited the Triassic seas of China. The genus contains the type and only known species, D. orientalis, which was named by Chun Li in 2003. Unlike other long-necked protorosaurs, Dinocephalosaurus convergently evolved a long neck not through elongation of individual neck vertebrae, but through the addition of neck vertebrae that each had a moderate length. As indicated by phylogenetic analyses, it belonged in a separate lineage that also included at least its closest relative Pectodens, which was named the Dinocephalosauridae in 2021. Like tanystropheids, however, Dinocephalosaurus probably used its long neck to hunt, utilizing the fang-like teeth of its jaws to ensnare prey; proposals that it employed suction feeding have not been universally accepted. It was probably a marine animal by necessity, as suggested by the poorly-ossified and paddle-like limbs which would have prevented it from going ashore.
Tanystropheus is an extinct genus of archosauromorph reptile which lived during the Triassic Period in Europe, Asia, and North America. It is recognisable by its extremely elongated neck, longer than the torso and tail combined. The neck was composed of 13 vertebrae strengthened by extensive cervical ribs. Tanystropheus is one of the most well-described non-archosauriform archosauromorphs, known from numerous fossils, including nearly complete skeletons. Some species within the genus may have reached a total length of 6 meters (20 ft), making Tanystropheus the longest non-archosauriform archosauromorph as well. Tanystropheus is the namesake of the family Tanystropheidae, a clade collecting many long-necked Triassic archosauromorphs previously described as "protorosaurs" or "prolacertiforms".
Macrocnemus is an extinct genus of archosauromorph reptile known from the Middle Triassic of Europe and China. Macrocnemus is a member of the Tanystropheidae family and includes three species. Macrocnemus bassanii, the first species to be named and described, is known from the Besano Formation and adjacent paleontological sites in the Italian and Swiss Alps. Macrocnemus fuyuanensis, on the other hand, is known from the Zhuganpo Formation in southern China. A third species, Macrocnemus obristi, is known from the Prosanto Formation of Switzerland and is characterized by gracile limbs. The name Macrocnemus is Greek for "long tibia".
Langobardisaurus is an extinct genus of tanystropheid archosauromorph reptile, with one valid species, L. pandolfii. Its fossils have been found in Italy and Austria, and it lived during the Late Triassic period, roughly 228 to 201 million years ago. Langobardisaurus was initially described in 1994, based on fossils from the Calcare di Zorzino Formation in Northern Italy. Fossils of the genus are also known from the Forni Dolostone of Northern Italy and the Seefeld Formation of Austria.
Protanystropheus is an extinct genus of archosauromorph from the Middle Triassic of Poland, Germany, Austria and the Netherlands. It was named by Sennikov in 2011 and the type species is Protanystropheus antiquus, first described in 1908 by German paleontologist Friedrich von Huene under the name Tanystropheus antiquus. Sennikov (2011) referred to Protanystropheus several vertebrae, including those belonging to "Thecodontosaurus" primus, but such a referral has later been questioned, because these specimens may represent other basal archosauromorphs.
Sinosaurosphargis is an extinct genus of basal marine saurosphargid reptile known from the Middle Triassic Guanling Formation of Yunnan and Guizhou Provinces, southwestern China. It contains a single species, Sinosaurosphargis yunguiensis.
Jesairosaurus is an extinct genus of early archosauromorph reptile known from the Illizi Province of Algeria. It is known from a single species, Jesairosaurus lehmani. Although a potential relative of the long-necked tanystropheids, this lightly-built reptile could instead be characterized by its relatively short neck as well as various skull features.
Protorosauria is an extinct, likely paraphyletic group of basal archosauromorph reptiles from the latest Middle Permian to the end of the Late Triassic of Asia, Europe and North America. It was named by the English anatomist and paleontologist Thomas Henry Huxley in 1871 as an order, originally to solely contain Protorosaurus. Other names which were once considered equivalent to Protorosauria include Prolacertiformes and Prolacertilia.
Tanystropheidae is an extinct family of archosauromorph reptiles that lived throughout the Triassic Period, often considered to be "protorosaurs". They are characterized by their long, stiff necks formed from elongated cervical vertebrae with very long cervical ribs. Members of the group include both terrestrial and aquatic forms. While some tanystropheids were small lizard-like animals, other tanystropheids such as Tanystropheus were large animals that had necks that were several meters long, longer than the rest of their bodies.
Fuyuansaurus is an extinct genus of "protorosaur" reptiles known from the Middle Triassic Zhuganpo Formation of southern China. Fuyuansaurus was first named by Nicholas C. Fraser, Olivier Rieppel and Li Chun in 2013 and the type species is Fuyuansaurus acutirostris.
Saurosphargidae is an extinct family of marine reptiles known from the Early Triassic and early Middle Triassic of Europe and China.
Pectodens is an extinct genus of archosauromorph reptile which lived during the Middle Triassic in China. The type and only species of the genus is P. zhenyuensis, named by Chun Li and colleagues in 2017. It was a member of the Archosauromorpha, specifically part of the unnatural grouping Protorosauria. However, an unusual combination of traits similar and dissimilar to other protorosaurs initially led to confusion over its evolutionary relationships. In 2021, it was placed in a newly-established group, Dinocephalosauridae, along with its closest relative Dinocephalosaurus.
Rhombopholis is an extinct genus of archosauromorph reptile known from England. The type species of Rhombopholis is Rhombopholis scutulata. Specimens of this genus were collected from the Leamington quarry, near Warwick. This locality belongs to the Bromsgrove Sandstone Formation, which is dated to the Anisian age of the Middle Triassic, approximately 245 million years ago.
Raibliania is an extinct genus of tanystropheid archosauromorph discovered in the Calcare del Predil Formation in Italy. It lived during the Carnian stage of the Late Triassic and it was related to Tanystropheus. Raibliania is distinct from Tanystropheus due to some distinct features of the cervical vertebrae and teeth. The type species is Raibliania calligarisi, named in 2020. The holotype consists of a partial post-cranial skeleton, with the known elements including vertebrae, a single tooth, several ribs, gastralia and parts of the pelvis.
Trachelosaurus is an extinct genus of lizard-like early archosauromorph reptiles in the family Trachelosauridae. It was originally described as a dinosaur until it was redescribed as a "protorosaur" reptile by Robert L. Carroll in 1988. The type species, T. fischeri, was described by F. Broili & E. Fischer in 1917 based on remains found in the Solling Formation (Buntsandstein), Bernburg, Germany. A 2024 redescription identified Trachelosaurus as a long-necked and presumably aquatic reptile closely related to Dinocephalosaurus from the Guanling Formation of China.
Trachelosauridae is an extinct clade of archosauromorph reptiles that lived throughout the Triassic period. Like their close relatives the tanystropheids, they were "protorosaur"-grade archosauromorphs characterized by their long necks. Unlike tanystropheids, which lengthen their neck primarily by elongating the individual cervical (neck) vertebrae, trachelosaurids achieved their long necks by the addition of more vertebrae. The most extreme example of this trend was Dinocephalosaurus, which had at least 32 vertebrae in the neck alone, far more than the 13 neck vertebrae of Tanystropheus.
Luopingosaurus is an extinct genus of pachypleurosaurid sauropterygian from the Middle Triassic Guanling Formation of Yunnan Province, China. The genus contains a single species, L. imparilis, known from a well-preserved, nearly complete skeleton.
Luxisaurus is an extinct genus of tanystropheid archosauromorph reptile from the Middle Triassic (Anisian) Guanling Formation of China. The genus contains a single species, L. terrestris, known from an articulated partial skeleton. Luxisaurus is hypothesized to have lived a more terrestrial lifestyle than many other tanystropheids, which may have been aquatic.
Austronaga is an extinct genus of dinocephalosaurid archosauromorph reptile from the Middle Triassic (Anisian) Guanling Formation of China. The genus contains a single species, A. minuta, known from a partial skull, as well as vertebrae from the tail and neck. Austronaga was significantly smaller than the coeval Dinocephalosaurus.
Tanysauria is an extinct clade long-necked archosauromorph reptiles from the Triassic period of Europe, Asia, North America, and South America. It comprises the families Tanystropheidae and Trachelosauridae. Within the Archosauromorpha, Tanysauria represents the sister group to the Crocopoda. It contains many of the species formerly placed in "Protorosauria", which is now thought to be a paraphyletic group.
