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.
Melanorosaurus is a genus of basal sauropodomorph dinosaur that lived during the Late Triassic period. An omnivore from South Africa, it had a large body and sturdy limbs, suggesting it moved quadrupedally. Its limb bones were massive and heavy like the limb bones of true sauropods.
Isanosaurus is an extinct genus of sauropod dinosaur from Thailand. It was originally dated to approximately 210 million years ago during the Late Triassic, which would make it one of the oldest known sauropods. Its age was later considered uncertain, and may be Early Jurassic or even as young as Late Jurassic. The only species is Isanosaurus attavipachi. Though important for the understanding of sauropod origin and early evolution, Isanosaurus is poorly known. Exact relationships to other early sauropods remain unresolved.
Lessemsaurus is an extinct genus of sauropodiform dinosaur belonging to Lessemsauridae.
Lufengosaurus is a genus of massospondylid dinosaur which lived during the Early Jurassic period in what is now southwestern China.
Antetonitrus is a genus of sauropodiform dinosaur found in the Early Jurassic Elliot Formation of South Africa. The only species is Antetonitrus ingenipes. Sometimes considered a basal sauropod, it is crucial for the understanding of the origin and early evolution of this group. It was a quadrupedal herbivore, like its later relatives, but shows primitive adaptations to use the forelimbs for grasping, instead of purely for weight support.
Blikanasaurus is a genus of sauropodomorph dinosaur from the late Triassic of South Africa. The generic name Blikanasaurus is derived from Greek, meaning "lizard from Blikana". The species name cromptoni is taken from the surname of A.W. "Fuzz" Crompton, an American paleontologist who led numerous field expeditions in Elliot Formation outcrop localities in South Africa. Blikanasaurus is only known from partial hindlimb bones that were recovered from the lower Elliot Formation (LEF) in the Eastern Cape.
Coloradisaurus 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.
Gresslyosaurus is a genus of plateosaurian sauropodomorph dinosaur that lived during the Late Triassic period, around 214 to 204 million years ago, in France, Germany, Norway, Greenland and Switzerland.
Massospondylidae is a family of early massopod dinosaurs that existed in Asia, Africa, North America, South America and Antarctica during the Late Triassic to the Early Jurassic periods. Several dinosaurs have been classified as massospondylids over the years. The largest cladistic analysis of early sauropodomorphs, which was presented by Apaldetti and colleagues in November 2011, found Adeopapposaurus, Coloradisaurus, Glacialisaurus, Massospondylus, Leyesaurus and Lufengosaurus to be massospondylids. This result supports many previous analyses that tested fewer taxa. However, this analysis found the two recently described North American massopods, Sarahsaurus and Seitaad, and the South African Ignavusaurus to nest outside Massospondylidae, as opposed to some provisional proposals. Earlier in 2011, Pradhania, a sauropodomorph from India, was tested for the first time in a large cladistic analysis and was found to be a relatively basal massospondylid. Mussaurus and Xixiposaurus may also be included within Massospondylidae.
Glacialisaurus is a genus of sauropodomorph dinosaur. It lived during the Pliensbachian stage of the Early Jurassic period around 186 to 182 million years ago in what is now the central region of the Transantarctic Mountains 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 Hanson Formation of Antarctica. They 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 species name honors Hammer.
Massopoda is a clade of sauropodomorph dinosaurs which lived during the Late Triassic to Late Cretaceous epochs. It was named by paleontologist Adam M. Yates of the University of the Witwatersrand in 2007. Massopoda is a stem-based taxon, defined as all animals more closely related to Saltasaurus loricatus than to Plateosaurus engelhardti.
Adeopapposaurus is a genus of plateosaurian 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.
Aardonyx is a genus of basal sauropodomorph dinosaur. It is known from the type species Aardonyx celestae found from the Early Jurassic Elliot Formation of South Africa. A. celestae was named after Celeste Yates, who prepared much of the first known fossil material of the species. It has arm features that are intermediate between basal sauropodomorphs and more derived sauropods.
Leyesaurus is an extinct genus of massospondylid sauropodomorph dinosaur known from the San Juan Province, northwestern Argentina.
Pulanesaura is an extinct genus of basal sauropodiform known from the Early Jurassic Upper Elliot Formation of the Free State, South Africa. It contains a single species, Pulanesaura eocollum, known from partial remains of at least two subadult to adult individuals.
Xingxiulong is a genus of bipedal sauropodiform from the Early Jurassic of China. It contains a single species, X. chengi, described by Wang et al. in 2017 from three specimens, two adults and an immature individual, that collectively constitute a mostly complete skeleton. Adults of the genus measured 4–5 metres (13–16 ft) long and 1–1.5 metres tall. Phylogenetic analysis suggests that Xingxiulong is most closely related to its contemporary Jingshanosaurus, although an alternative position outside of both the Sauropodiformes and Massospondylidae is also plausible.
Lessemsauridae is a clade of early sauropodiform dinosaurs that lived in the Triassic and Jurassic of Argentina, South Africa and possibly Lesotho. A phylogenetic analysis performed by Apaldetti and colleagues in 2018 recovered a new clade of sauropodiforms uniting Lessemsaurus, Antetonitrus, and Ingentia which they named Lessemsauridae. It is a node-based taxon, defined as all descendants of the most recent common ancestor of Lessemsaurus sauropoides and Antetonitrus ingenipes. Depending on the definition of Sauropoda, Lessemsauridae is either one of the most basal sauropod taxa, or a sister taxon of Sauropoda. An additional member of the clade was named later in 2018, Ledumahadi. A 2021 study by Pol and colleagues also assigned the genera Kholumolumo and Meroktenos to the group.
Schleitheimia, is an extinct genus of sauropodiform sauropodomorph dinosaur, from the Gruhalde Member of Klettgau Formation of Switzerland. The type species, Schleitheimia schutzi was formally described in 2020.
