Archosauromorpha is a clade of diapsid reptiles containing all reptiles more closely related to archosaurs rather than lepidosaurs. Archosauromorphs first appeared during the late Middle Permian or Late Permian, though they became much more common and diverse during the Triassic period.
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".
Coelurus is a genus of coelurosaurian dinosaur from the Late Jurassic period. The name means "hollow tail", referring to its hollow tail vertebrae. Although its name is linked to one of the main divisions of theropods (Coelurosauria), it has historically been poorly understood, and sometimes confused with its better-known contemporary Ornitholestes. Like many dinosaurs studied in the early years of paleontology, it has had a confusing taxonomic history, with several species being named and later transferred to other genera or abandoned. Only one species is currently recognized as valid: the type species, C. fragilis, described by Othniel Charles Marsh in 1879. It is known from one partial skeleton found in the Morrison Formation of Wyoming, United States. It was a small bipedal carnivore with elongate legs.
Podokesaurus is a genus of coelophysoid dinosaur that lived in what is now the eastern United States during the Early Jurassic Period. The first fossil was discovered by the geologist Mignon Talbot near Mount Holyoke, Massachusetts, in 1910. The specimen was fragmentary, preserving much of the body, limbs, and tail. In 1911, Talbot described and named the new genus and species Podokesaurus holyokensis based on it. The full name can be translated as "swift-footed lizard of Holyoke". This discovery made Talbot the first woman to find and describe a non-bird dinosaur. The holotype fossil was recognized as significant and was studied by other researchers, but was lost when the building it was kept in burned down in 1917; no unequivocal Podokesaurus specimens have since been discovered. It was made state dinosaur of Massachusetts in 2022.
Rapator is a genus of theropod dinosaur from the Griman Creek Formation of New South Wales, Australia, dating to the Cenomanian age of the Cretaceous period. It contains only the type species, Rapator ornitholestoides, which was originally named by Friedrich von Huene in 1932.
Halticosaurus (pron.:"HAL-tick-oh-SORE-us") is a dubious genus of theropod dinosaur from the late Triassic period. It is known from a single fragmentary fossil specimen of the species H. longotarsus, found in the Middle Stubensandstein formation of what is present-day Germany The only known specimen was poorly preserved and may have been put together from bones of unrelated animals. Further research would be required to determine which of the bones belonged together, and what kind of theropod Halticosaurus was. However, most of the bones have been lost. For these reasons, Halticosaurus is considered to be a nomen dubium.
Teratosaurus is a genus of rauisuchians known from the Triassic Stubensandstein of Germany. It is estimated to be 6.2 meters (20.35 ft) long.
Spinosuchus is an extinct genus of trilophosaurid allokotosaur from the Late Triassic of Texas, southern United States. It has been assigned to a variety of groups over its history, from coelophysid dinosaur to pseudosuchian to uncertain theropod dinosaur and to Proterosuchidae. This uncertainty is not unusual, given that it was only known from a poorly preserved, wall-mounted, partial vertebral column of an animal that lived in a time of diverse, poorly known reptile groups. However, newly collected material and recent phylogenetic studies of early archosauromorphs suggest that it represents an advanced trilophosaurid very closely related to Trilophosaurus.
Mecistotrachelos is an extinct genus of gliding reptile from the Late Triassic of Virginia. It is generally interpreted as an archosauromorph, distantly related to crocodylians and dinosaurs. The type and only known species is M. apeoros. This specific name translates to "soaring longest neck", in reference to its gliding habits and long neck. This superficially lizard-like animal was able to spread its lengthened ribs and glide on wing-like membranes. Mecistotrachelos had a much longer neck than other gliding reptiles of the Triassic such as Icarosaurus and Kuehneosaurus. It was probably an arboreal insectivore.
Rhabdopelix is a dubious genus of possible kuehneosaurid reptile, from the Late Triassic-age Lockatong Formation of Pennsylvania, United States. Based on partial, possibly chimeric remains, it was described by American naturalist and paleontologist Edward Drinker Cope as an early pterosaur. It held this status until the 1960s, when Ned Colbert reevaluated it for his description of Icarosaurus. He noted that the bones came from a block with the remains of other animals, and that Cope had misinterpreted some of the remains; for example, the rod-like "pubic bones" that had given it its name were actually much more like the bony structures used by Icarosaurus and related animals to glide. Additionally, he couldn't relocate the fossils, which are assumed to be lost. He recommended considering Rhabdopelix a dubious name. Peter Wellnhofer retained it as a pterosaur of unknown affinities in his 1978 review, but rejected this by 1991.
The Triassic Lockatong Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It is named after the Lockatong Creek in Hunterdon County, New Jersey.
Rauisuchus is a genus of extinct archosaurs which lived in what is now the Geopark of Paleorrota, Brazil, during the Late Triassic period. It contains one species, R. tiradentes.
Stegomosuchus is an extinct genus of small protosuchian crocodyliform. It is known from a single incomplete specimen discovered in the late 19th century in Lower Jurassic rocks of south-central Massachusetts, United States. It was originally thought to be a species of Stegomus, an aetosaur, but was eventually shown to be related to Protosuchus and thus closer to the ancestry of crocodilians. Stegomosuchus is also regarded as a candidate for the maker of at least some of the tracks named Batrachopus in the Connecticut River Valley.
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.
Cosesaurus is a genus of archosauromorph reptiles likely belonging to the family Tanystropheidae. It is known from fossil imprints of a single small skeleton, MGB V1, which was found in Muschelkalk outcrops near the municipalities of Mont-ral and Alcover in Spain. These outcrops are dated to the Ladinian age of the middle Triassic about 242 to 237 million years ago. The specimen is stored at the Museu Martorell, which is now part of the Museu de Ciències Naturals de Barcelona. The poor preservation and likely juvenile nature of the specimen has led to the anatomy of Cosesaurus being misidentified by several different sources. For example, Paul Ellenberger claimed that it was an ancestor to birds in the 1970s, while David Peters claimed that it was a pterosaur ancestor in 2000. Both of these claims contrast with mainstream scientific theories on the origins of either group, and other paleontologists who study the specimen are unable to find the features which Ellenberger or Peters reported to be present. The Ellenberger and Peters hypotheses are thus considered fringe theories with questionable scientific soundness due to their low reproducibility. Mainstream hypotheses for the relations of Cosesaurus generally agree that it is a "protorosaur", specifically a tanystropheid closely related to long-necked reptiles such as Macrocnemus, Tanytrachelos, Tanystropheus, or Langobardisaurus.
Tanytrachelos is an extinct genus of tanystropheid archosauromorph reptile from the Late Triassic of the eastern United States. It contains a single species, Tanytrachelos ahynis, which is known from several hundred fossil specimens preserved in the Solite Quarry in Cascade, Virginia. Abundant fossils of Tanytrachelos are found in a series of lakebed sediments that were deposited over the course of about 350 thousand years in a lake which existed approximately 230 million years ago. Some fossils are very well-preserved and include the remains of soft tissues. Tanytrachelos is the most likely trackmaker of the ichnogenus Gwyneddichnium.
Saurosphargis is an extinct genus of a basal marine reptile, saurosphargid, known from the Middle Triassic of southwestern Poland and eastern Netherlands. It contains a single species, Saurosphargis volzi.
Ozimek is a genus of sharovipterygid archosauromorph reptile, known from Late Triassic deposits in Poland and closely related to the Kyrgyzstani Sharovipteryx. It contains one species, O. volans, named in 2016 by Jerzy Dzik and Tomasz Sulej. Like Sharovipteryx, Ozimek had long, slender limbs with the hindlimbs longer than the forelimbs; the hindlimbs likely supported gliding membranes as fossilized in Sharovipteryx. Another unusual characteristic was the shoulder girdle, where the massive coracoids formed a shield-like structure covering the bottom of the shoulder region that would have limited mobility. In other respects, such as its long neck, it was a typical member of the non-natural grouping Protorosauria. Phylogenetic analysis has indicated that it, possibly along with Sharovipteryx, may have been an unusual member of the protorosaur group Tanystropheidae, although further study of its anatomy is needed to resolve its precise relationships.
Megacnemus is an extinct genus of archosauromorph reptile. Megacnemus is an enigmatic and poorly described genus, known from a single bone. The type species of Megacnemus, Megacnemus grandis, was named by Friedrich von Huene in 1954. The holotype of Megacnemus is a limb bone, believed to be a femur. Although the exact locality from which this bone was unearthed is unknown, it is believed to have come from Middle Triassic deposits near Gogolin, in southwest Poland. As the bone is more than 20 centimeters long, Megacnemus may have been quite large, similar to Vritraminosaurus in size.
Gwyneddichnium is an ichnogenus from the Late Triassic of North America and Europe. It represents a form of reptile footprints and trackways, likely produced by small tanystropheids such as Tanytrachelos. Gwyneddichnium includes a single species, Gwyneddichnium major. Two other proposed species, G. elongatum and G. minore, are indistinguishable from G. major apart from their smaller size and minor taphonomic discrepancies. As a result, they are considered junior synonyms of G. major.
