Sauropoda, whose members are known as sauropods, is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads, and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include Apatosaurus, Argentinosaurus, Alamosaurus, Brachiosaurus, Camarasaurus, Diplodocus, and Mamenchisaurus.
Titanosaurs were a diverse group of sauropod dinosaurs, including genera from all seven continents. The titanosaurs were the last surviving group of long-necked sauropods, with taxa still thriving at the time of the extinction event at the end of the Cretaceous. This group includes some of the largest land animals known to have ever existed, such as Patagotitan—estimated at 37 m (121 ft) long with a weight of 69 tonnes —and the comparably-sized Argentinosaurus and Puertasaurus from the same region.
Antarctosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. The type species, Antarctosaurus wichmannianus, and a second species, Antarctosaurus giganteus, were described by prolific German paleontologist Friedrich von Huene in 1929. Three additional species of Antarctosaurus have been named since then but later studies have considered them dubious or unlikely to pertain to the genus.
Aeolosaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous Period of what is now South America. Like most sauropods, it would have been a quadrupedal herbivore with a long neck and tail. Aeolosaurus is well known for a titanosaur, as it is represented by the remains of several individuals belonging to at least two species. However, like most titanosaurs, no remains of the skull are known. The holotype of Aeolosaurus rionegrinus consists of a series of seven tail vertebrae, as well as parts of both forelimbs and the right hindlimb. It was discovered in the Angostura Colorada Formation in Argentina, which dates from the Campanian stage of the Late Cretaceous, about 83 to 74 million years ago. The species A. maximus was transferred over to the new genus Arrudatitan in 2021.
Bonitasaura is a genus of titanosaurian dinosaur hailing from uppermost layers of the Late Cretaceous (Santonian) Bajo de la Carpa Formation, Neuquén Group of the eastern Neuquén Basin, located in Río Negro Province, Northwestern Patagonia, Argentina. The remains, consisting of a partial sub-adult skeleton jumbled in a small area of fluvial sandstone, including a lower jaw with teeth, a partial vertebrae series, and limb bones, were described by Sebastian Apesteguía in 2004.
Macronaria is a clade of sauropod dinosaurs. Macronarians are named after the large diameter of the nasal opening of their skull, known as the external naris, which exceeded the size of the orbit, the skull opening where the eye is located. Fossil evidence suggests that macronarian dinosaurs lived from the Middle Jurassic (Bathonian) through the Late Cretaceous (Maastrichtian). Macronarians have been found globally, including discoveries in Argentina, the United States, Portugal, China, and Tanzania. Like other sauropods, they are known to have inhabited primarily terrestrial areas, and little evidence exists to suggest that they spent much time in coastal environments. Macronarians are diagnosed through their distinct characters on their skulls, as well as appendicular and vertebral characters. Macronaria is composed of several subclades and families notably including Camarasauridae and Titanosauriformes, among several others. Titanosauriforms are particularly well known for being some of the largest terrestrial animals to ever exist.
Andesaurus is a genus of basal titanosaurian sauropod dinosaur which existed during the middle of the Cretaceous Period in South America. Like most sauropods, belonging to one of the largest animals ever to walk the Earth, it would have had a small head on the end of a long neck and an equally long tail.
Clasmodosaurus is a genus of titanosaurian sauropod dinosaur from the Mata Amarilla Formation and the Cerro Fortaleza Formation. It lived during the Late Cretaceous in what is now Argentina. It is known from five fossilized and assorted teeth, but is diagnosed by a unique combination of characters.
Amargatitanis is a genus of dicraeosaurid sauropod dinosaur from the Barremian-age La Amarga Formation of Neuquén, Argentina. It is known from a single, incomplete postcranial skeleton consisting of a partial hindlimb, ischium, and two vertebrae. These remains were unearthed by Argentine paleontologist José Bonaparte in 1983 during an expedition by the Museo Argentino de Ciencias Naturales and later described as a new genus and species, Amargatitanis macni by Sebastián Apesteguía. The genus name comes from the words Amarga, where the fossils were collected, and titanis meaning "titan". Its species name is in reference to the MACN, where the remains are stored.
Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch et al. in 2004 as the most recent common ancestor of Malawisaurus and Saltasaurus and all the descendants of that ancestor. Lithostrotia is derived from the Ancient Greek lithostros, meaning "inlaid with stones", referring to the fact that many known lithostrotians are preserved with osteoderms. However, osteoderms are not a distinguishing feature of the group, as the two noted by Unchurch et al. include caudal vertebrae with strongly concave front faces (procoely), although the farthest vertebrae are not procoelous.
Uberabatitan is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Brazil. It is known from bones including neck, back, and tail vertebrae, pelvic bones, and limb bones. These fossils were found in the uppermost portion of the Maastrichtian-age Serra da Galga Formation of the Bauru Group, in Uberaba, Minas Gerais. The type species, described by Salgado and Carvalho in 2008, is U. ribeiroi. To date, it is the most recent titanosaur from Bauru Group rocks; other titanosaurs from the Bauru Group, including Baurutitan and Trigonosaurus, come from lower levels.
Lognkosauria is a clade of giant long-necked sauropod dinosaurs within the clade Titanosauria. It includes some of the largest and heaviest dinosaurs known. They lived in South America and likely Asia during the Late Cretaceous period.
Leinkupal is a genus of diplodocine sauropod known from the Early Cretaceous of the Bajada Colorada Formation, southeastern Neuquén Basin in the Neuquén Province of Argentina. It contains a single species, Leinkupal laticauda.
Patagotitan is a genus of titanosaurian sauropod dinosaur from the Cerro Barcino Formation in Chubut Province, Patagonia, Argentina. The genus contains a single species known from at least six young adult individuals, Patagotitan mayorum, which was first announced in 2014 and then named in 2017 by José Carballido and colleagues. Preliminary studies and press releases suggested that Patagotitan was the largest known titanosaur and land animal overall, with an estimated length of 37 m (121 ft) and an estimated weight of 69 tonnes. Later research revised the length estimate down to 31 m (102 ft) and weight estimates down to approximately 50–57 tonnes, suggesting that Patagotitan was of a similar size to, if not smaller than, its closest relatives Argentinosaurus and Puertasaurus. Still, Patagotitan is one of the most-known titanosaurs, and so its interrelationships with other titanosaurs have been relatively consistent in phylogenetic analyses. This led to its use in a re-definition of the group Colossosauria by Carballido and colleagues in 2022.
Rinconsauria is an extinct clade of giant titanosaurian sauropods known from the late Cretaceous period of Argentina.
Bajadasaurus is a genus of sauropod dinosaur from the Early Cretaceous epoch of northern Patagonia, Argentina. It was first described in 2019 based on a single specimen found in 2010 that includes a largely complete skull and parts of the neck. The only species is Bajadasaurus pronuspinax. The genus is classified as a member of the Dicraeosauridae, a group of relatively small and short-necked sauropods.
The Bajada Colorada Formation is a geologic formation of the southern Neuquén Province in the Neuquén Basin of northern Patagonia, Argentina. The formation belongs to the Mendoza Group and is Late Berriasian to Early Valanginian in age. The formation is renowned for preserving fossil remains of Bajadasaurus pronuspinax, a genus of dicraeosaurid dinosaurs named after the formation.
Colossosauria is a clade of titanosaur sauropods from the latest Early Cretaceous through the Late Cretaceous of South America. The group was originally named by Bernardo González-Riga et al. in 2019 and defined as the "most inclusive clade containing Mendozasaurus neguyelap but not Saltasaurus loricatus or Epachthosaurus sciuttoi". The clade contains different taxa depending on the phylogenetic analysis used, in the defining paper the only subgroups were Rinconsauria and Lognkosauria, but alternate phylogenies published previously had also included various similar titanosaurs such as Aeolosaurus, Bonitasaura, Drusilasaura, Overosaurus and Quetecsaurus. The phylogenetic analysis of González-Riga et al. (2019) placed Colossosauria as sister taxa to Epachthosaurus, Pitekunsaurus and a larger clade including Saltasauridae.
Inawentu is an extinct genus of titanosaurian sauropod dinosaur from the Late Cretaceous Bajo de la Carpa Formation of Argentina. The genus contains a single species, I. oslatus, known from a partial articulated skeleton including the skull. The square-shaped jaw of Inawentu demonstrates convergent characteristics with rebbachisaurids.
Sidersaura is an extinct genus of rebbachisaurid sauropod dinosaur from the Late Cretaceous Huincul Formation of Argentina. The genus contains a single species, S. marae, known from the remains of four individuals. Sidersaura represents one of the largest known rebbachisaurids.
