| Unaysaurids Temporal range: Late Triassic, | |
|---|---|
 | |
| Restoration of Unaysaurus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Clade: | Saurischia |
| Clade: | † Sauropodomorpha |
| Clade: | † Bagualosauria |
| Clade: | † Unaysauridae Müller et al., 2018 |
| Genera | |
Unaysauridae is a clade of basal sauropodomorphs from the Late Triassic of India and Brazil.
Unaysauridae was defined by Müller et al. (2018) as the most inclusive clade including Unaysaurus tolentinoi, but not Plateosaurus engelhardti nor Saltasaurus loricatus . [1]
Members of Unaysauridae are diagnosed by a substantially expanded cranial part of the medial condyle of the astragalus, as well as a promaxillary fenestra. Unaysauridae is sister to Plateosauria, more derived than Nambalia , Thecodontosaurus ISI R277, Pantydraco , and Efraasia . [1] Unaysaurus and Jaklapallisaurus had previously been assigned to Plateosauridae by prior authors. [2] [3] However, Beccari et al. (2021) questioned the validity of Unaysauridae in their description of Issi saaneq because it "suffers from the missing data and fragmentary nature of specimens. For example, one synapomorphy of unaysaurids is related to the astragalus medial end length ratio to the anteroposterior length of the lateral end, a which has not been confirmed in U. tolentinoi, whereas a second synapomorphy, the presence of a promaxillary fenestra, cannot be observed in J. asymmetrica which lacks the required cranial remains." [4] Subsequently, their phylogenetic analysis recovered Unaysaurus and Macrocollum within Plateosauridae. [4]
Eoraptor is a genus of small, lightly built, basal sauropodomorph dinosaur. One of the earliest-known dinosaurs and one of the earliest sauropodomorphs, 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.
Sauropodomorpha is an extinct clade of long-necked, herbivorous, saurischian dinosaurs that includes the sauropods and their ancestral relatives. Sauropods generally grew to very large sizes, had long necks and tails, were quadrupedal, and became the largest animals to ever walk the Earth. The prosauropods, which preceded the sauropods, were smaller and were often able to walk on two legs. The sauropodomorphs were the dominant terrestrial herbivores throughout much of the Mesozoic Era, from their origins in the Late Triassic until their decline and extinction at the end of the Cretaceous.
Staurikosaurus is a genus of herrerasaurid dinosaur from the Late Triassic of Brazil, found in the Santa Maria Formation.
Unaysaurus 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.
Herrerasauridae is a family of carnivorous dinosaurs, possibly basal to either theropods or even all of saurischians, or even their own branching from Dracohors, separate from Dinosauria altogether. They are among the oldest known dinosaurs, first appearing in the fossil record around 233.23 million years ago, before becoming extinct by the end of the Carnian stage. Herrerasaurids were relatively small-sized dinosaurs, normally no more than 4 metres (13 ft) long, although the holotype specimen of "Frenguellisaurus ischigualastensis" is thought to have reached around 6 meters long. The best known representatives of this group are from South America, where they were first discovered in the 1930s in relation to Staurikosaurus and 1960s in relation to Herrerasaurus. A nearly complete skeleton of Herrerasaurus ischigualastensis was discovered in the Ischigualasto Formation in San Juan, Argentina, in 1988. Less complete possible herrerasaurids have been found in North America and Africa, and they may have inhabited other continents as well.
Herrerasaurus is likely a genus of saurischian dinosaur from the Late Triassic period. Measuring 6 m (20 ft) long and weighing around 350 kg (770 lb), 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.
Chindesaurus 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.
Plateosauridae is a family of plateosaurian sauropodomorphs from the Late Triassic of Europe, Greenland, Africa and Asia. Although several dinosaurs have been classified as plateosaurids over the years, the family Plateosauridae is now restricted to Plateosaurus, Yimenosaurus, Euskelosaurus, and Issi. In another study, Yates (2003) sunk Sellosaurus into Plateosaurus. Gresslyosaurus is alternatively considered its own genus or a synonym of Plateosaurus.
Neosauropoda is a clade within Dinosauria, coined in 1986 by Argentine paleontologist José Bonaparte and currently described as Saltasaurus loricatus, Diplodocus longus, and all animals directly descended from their most recent common ancestor. The group is composed of two subgroups: Diplodocoidea and Macronaria. Arising in the early Jurassic and persisting until the Cretaceous–Paleogene extinction event, Neosauropoda contains the majority of sauropod genera, including genera such as Apatosaurus, Brachiosaurus, and Diplodocus. It also includes giants such as Argentinosaurus, Patagotitan and Sauroposeidon, and its members remain the largest land animals ever to have lived.
Guaibasauridae is a family of basal sauropodomorph dinosaurs, known from fossil remains of late Triassic period formations in Brazil, Argentina and India.
Glacialisaurus is a genus of sauropodomorph dinosaur from the Early Jurassic period of Antarctica. It is known from two specimens; the holotype, a partial tarsus (ankle) and metatarsus, and a partial left femur. The fossils were collected by a team led by paleontologist William R. Hammer during a 1990–91 field expedition to the central region of the Transantarctic Mountains. They come from sedimentary rocks of the Hanson Formation and date to the Pliensbachian stage of the Early Jurassic, around 186 to 182 million years ago. The fossils were described in 2007, and made the basis of the new genus and species Glacialisaurus hammeri. The genus name translates as “icy” or "frozen lizard”, and the specific name honors Hammer.
Lagerpetidae is a family of basal avemetatarsalians. Though traditionally considered the earliest-diverging dinosauromorphs, fossils described in 2020 suggest that lagerpetids may instead be pterosauromorphs. Lagerpetid fossils are known from the Triassic of Argentina, Arizona, Brazil, Madagascar, New Mexico, and Texas. They were typically small, although some lagerpetids, like Dromomeron gigas and a specimen from the Santa Rosa Formation attributed to Dromomeron sp., were able to get quite large. Lagerpetid fossils are rare; the most common finds are bones of the hindlimbs, which possessed a number of unique features.
Saturnaliidae is a family of basal sauropodomorph dinosaurs found in Brazil, Argentina and possibly Zimbabwe. It is not to be confused with Saturnalidae, a family of radiolarian protists.
Eodromaeus 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.
Jaklapallisaurus is a genus of unaysaurid sauropodomorph dinosaur. It lived during the Late Triassic period in what is now Telangana, central India.The genus is monotypic, only including the species Jaklapallisaurus asymmetricus.
Pampadromaeus is an extinct genus of basal sauropodomorph dinosaurs known from the Late Triassic (Carnian) Santa Maria Formation of the Paraná Basin in Rio Grande do Sul, southern Brazil.
Buriolestes is a genus of early sauropodomorph dinosaurs from the Late Triassic Santa Maria Formation of the Paraná Basin in southern Brazil. It contains a single species, B. schultzi, named in 2016. The type specimen was found alongside a specimen of the lagerpetid dinosauromorph Ixalerpeton.
Macrocollum is a genus of unaysaurid sauropodomorph dinosaur that lived during the Late Triassic period in what is now Brazil. It is one of the oldest dinosaurs known.
Nhandumirim is a genus of basal sauropodomorph dinosaur from the Carnian age of Late Triassic Brazil. It is currently considered a saturnaliid sauropodomorph. The type and only species, Nhandumirim waldsangae, is known from a single immature specimen including vertebrae, a chevron, pelvic material, and a hindlimb found in the Santa Maria Formation in Rio Grande do Sul.
Issi is a plateosaurid dinosaur described in 2021 from the Late Triassic Fleming Fjord Formation of Greenland. It contains one species, Issi saaneq; the full binomial name means "cold bone".
