WAdeopapposaurus is a genus of prosauropod dinosaur from the Early Jurassic Cañón del Colorado Formation of San Juan, Argentina. It was similar to Massospondylus. Four partial skeletons with two partial skulls are known.
WAmygdalodon was a genus of basal sauropod from the Middle Jurassic of Argentina. The type species is Amygdalodon patagonicus. Fossils of Amygdalodon have been found in the Toarcian Cerro Carnerero Formation of the Jurassic. Very little is known about it, but it is one of the few Jurassic dinosaurs from South America found thus far.
WChindesaurus is an extinct genus of basal saurischian dinosaur from the Late Triassic of the southwestern United States. It is known from a single species, C. bryansmalli, based on a partial skeleton recovered from Petrified Forest National Park in Arizona. The original specimen was nicknamed "Gertie", and generated much publicity for the park upon its discovery in 1984 and airlift out of the park in 1985. Other fragmentary referred specimens have been found in Late Triassic sediments throughout Arizona, New Mexico, and Texas, but these may not belong to the genus. Chindesaurus was a bipedal carnivore, approximately as large as a wolf.
WColoradisaurus is a genus of massospondylid sauropodomorph dinosaur. It lived during the Late Triassic period in what is now La Rioja Province, Argentina. It is known from two specimens collected from the Los Colorados Formation of the Ischigualasto-Villa Unión Basin.
WCondorraptor is an extinct genus of megalosauroid theropod dinosaur. Its genus name means 'robber from Cerro Condor', referencing a nearby village, while its species name, currumili, is named after Hipolito Currumil, the landowner and discoverer of the locality. It was among the earliest large South American theropods, having been found in Lower Jurassic strata of the Cañadón Asfalto Formation in the Cañadón Asfalto Basin of Argentina. The type species, described in 2005, is Condorraptor currumili. It is based on a tibia, with an associated partial skeleton that may belong to the same individual. Initially described as a basal tetanuran, Benson (2010) found it to be a piatnitzkysaurid megalosauroid and the sister taxon of Piatnitzkysaurus, a finding supported by later studies.
WEoabelisaurus is a genus of abelisaurid theropod dinosaur from the Lower Jurassic Cañadón Asfalto Formation of the Cañadón Asfalto Basin in Argentina, South America. The generic name combines a Greek ἠώς, (eos), "dawn", with the name Abelisaurus, in reference to the fact it represents an early relative of the latter. Only one species is currently recognized, E. mefi; the specific name honours the MEF, the Museo Paleontológico "Egidio Feruglio", where discoverer Diego Pol is active. It is characterized by reduced forelimb proportions that show primitive characteristics of the Abelisauridae family.
WEodromaeus is an extinct genus of probable basal theropod dinosaurs from the Late Triassic of Argentina. Like many other of the earliest-known dinosaurs, it hails from the Carnian-age Ischigualasto Formation, within the Ischigualasto-Villa Unión Basin of northwestern Argentina. Upon its discovery, it was argued to be one of the oldest true theropods, supplanting its contemporary Eoraptor, which was reinterpreted as a basal sauropodomorph.
WEoraptor is a genus of small, lightly built, basal sauropodomorph. One of the earliest-known dinosaurs, it lived approximately 231 to 228 million years ago, during the Late Triassic in Western Gondwana, in the region that is now northwestern Argentina. The type and only species, Eoraptor lunensis, was first described in 1993, and is known from an almost complete and well-preserved skeleton and several fragmentary ones. Eoraptor had multiple tooth shapes, which suggests that it was omnivorous.
WGuaibasaurus is an extinct genus of basal sauropodomorph dinosaur known from the Late Triassic Caturrita Formation of Rio Grande do Sul, southern Brazil. It was possibly a basal theropod or sauropodomorph. In 2016 Gregory S. Paul estimated it at 2 meters and 10 kg, whereas in 2020 Molina-Pérez and Larramendi listed it at 3 meters and 35 kg.
WHerrerasaurus was a genus of saurischian dinosaur from the Late Triassic period. This genus was one of the earliest dinosaurs from the fossil record. Its name means "Herrera's lizard", after the rancher who discovered the first specimen in 1958 in South America. All known fossils of this carnivore have been discovered in the Ischigualasto Formation of Carnian age in northwestern Argentina. The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 and is the only species assigned to the genus. Ischisaurus and Frenguellisaurus are synonyms.
WLeonerasaurus is a basal genus of sauropodomorph dinosaur. Currently, there is only one species known, named L. taquetrensis by Diego Pol, Alberto Garrido and Ignacio A. Cerda in 2011. The fossil, an incomplete subadult individual, was found in the Las Leoneras Formation in Argentina. This formation is probably Early Jurassic in age. Leonerasaurus was a small non-sauropod sauropodomorph, showing an unusual combination of basal and derived characters. This indicates that the evolution of early sauropodomorphs witnessed a great degree of convergent evolution.
WLeptorhynchos is an extinct genus of caenagnathid dinosaurs known from the Late Cretaceous Aguja Formations of west Texas United States. It lived about 80.5–72 million years ago. It is distinguished from its relatives Chirostenotes and Anzu by its smaller size, and by a more strongly upturned mandible, similar to that of oviraptorids. The specializations of the beak in Leptorhynchos and other caenagnathids suggest that they were herbivores. The species L. elegans has since been transferred to the genus Citipes, leaving only the type species L. gaddisi in the genus.
WLessemsaurus is an extinct genus of sauropod dinosaur belonging to Lessemsauridae.
WLeyesaurus is an extinct genus of massospondylid sauropodomorph dinosaur known from the San Juan Province, northwestern Argentina.
WMussaurus is a genus of herbivorous sauropodomorph dinosaur that lived in southern Argentina during the Early Jurassic, with a maximum age of 192.8 Ma. It receives its name from the small size of the skeletons of juvenile and infant individuals, which were once the only known specimens of the genus. However, since Mussaurus is now known from adult specimens, the name is something of a misnomer; adults possibly reached 6 metres (20 ft) in length and weighed more than 1,000 kilograms (2,200 lb). Mussaurus possesses anatomical features suggesting a close, possibly transitional evolutionary relationship with true sauropods.
WNiebla is a genus of abelisaurid theropod dinosaur from the Late Cretaceous Period (Campanian-Maastrichtian) of Río Negro province, Argentina. The genus contains a single species, Niebla antiqua, and is known from a partial, non-articulated skeleton. The holotype, found in the Allen Formation, represents an adult individual.
WOverosaurus is an extinct genus of sauropod dinosaurs, containing only a single species, Overosaurus paradasorum. This species lived approximately 86 to 84 million years ago during the latter part of the Cretaceous Period in what is now Patagonia. Overosaurus paradasorum was relatively small compared to other sauropods from Patagonia, like the saltasaurids and other aeolosaurines. It was a ground-dwelling herbivore, relatively small for a sauropod, with a length estimated as approximately 10 m (33 ft) long.
WPanphagia is a genus of sauropodomorph dinosaur described in 2009. It lived around 231 million years ago, during the Carnian age of the Late Triassic period in what is now northwestern Argentina. Fossils of the genus were found in the La Peña Member of the Ischigualasto Formation in the Ischigualasto-Villa Unión Basin. The name Panphagia comes from the Greek words pan, meaning "all", and phagein, meaning "to eat", in reference to its inferred omnivorous diet. Panphagia is one of the earliest known dinosaurs, and is an important find which may mark the transition of diet in early sauropodomorph dinosaurs.
WPatagosaurus is an extinct genus of eusauropod dinosaur from the Middle-Late Toarcian of Patagonia, Argentina. It was first found in deposits of the Cañadón Asfalto Formation, which date to around 179 to 177 million years ago. Although originally twelve specimens were assigned to the taxon, at least one of them may belong to a different genus. Patagosaurus probably lived alongside genera as Piatnitzkysaurus, Condorraptor, and Volkheimeria.
WPiatnitzkysaurus is a genus of megalosauroid theropod dinosaur that lived approximately 179 to 177 million years ago during the lower part of the Jurassic Period in what is now Argentina. Piatnitzkysaurus was a moderately large, lightly built, bipedal, ground-dwelling carnivore that could grow up to 6.6 m (21.7 ft) long.
WRiojasaurus was a herbivorous sauropodomorph dinosaur named after La Rioja Province in Argentina where it was found in the Los Colorados Formation in the Ischigualasto-Villa Unión Basin by José Bonaparte. It lived during the Late Triassic and grew to about 10 metres (33 ft) long. Riojasaurus is the only known riojasaurid to live in South America.
WRukwatitan is a genus of titanosaur sauropod dinosaur from the Galula Formation in Tanzania. It lived around 100 million years ago, during the middle Cretaceous. The species, which shared features with another southern African species, Malawisaurus dixeyi, measured 30 feet (9.1 m) from the head to the tip of the tail, and had forelimbs that were estimated around 6.5 feet (2.0 m) long. Its fossils were found embedded in a cliff face near Lake Rukwa in the Rukwa Valley, from which it gets its name.
WSanjuansaurus is a genus of herrerasaurid dinosaur from the Late Triassic (Carnian) Cancha de Bochas and La Peña Members of the Ischigualasto Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina.
WStaurikosaurus is a genus of herrerasaurid dinosaur from the Late Triassic of Brazil, found in the Santa Maria Formation.
WTehuelchesaurus is a genus of dinosaur. It is named in honor of the Tehuelche people, native to the Argentinian province of Chubut, where it was first found.
WThecospondylus is a dubious genus of dinosaur from the Early Cretaceous of England. Scientists are unsure as to whether Thecospondylus was a saurischian or an ornithischian.
WTongtianlong is a genus of oviraptorid theropod dinosaurs that lived in the late Maastrichtian epoch of the late Cretaceous period. It contains one species, T. limosus.
WUnaysaurus is a genus of unaysaurid sauropodomorph herbivore dinosaur. Discovered in southern Brazil, in the geopark of Paleorrota, in 1998, and announced in a press conference on Thursday, December 3, 2004, it is one of the oldest dinosaurs known. It is closely related to plateosaurid dinosaurs found in Germany, which indicates that it was relatively easy for species to spread across the giant landmass of the time, the supercontinent of Pangaea.
WZupaysaurus is an extinct genus of early theropod dinosaur living during the Norian stage of the Late Triassic in what is now Argentina. Fossils of the dinosaur were found in the Los Colorados Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina. Although a full skeleton has not yet been discovered, Zupaysaurus can be considered a bipedal predator, up to 4 metres (13 ft) long. It may have had two parallel crests running the length of its snout.