Abdarainurus Temporal range: Late Cretaceous | |
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Skeletal reconstruction with known material in white | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | † Sauropodomorpha |
Clade: | † Sauropoda |
Clade: | † Macronaria |
Clade: | † Titanosauria |
Genus: | † Abdarainurus Averianov & Lopatin, 2020 |
Type species | |
†Abdarainurus barsboldi Averianov & Lopatin, 2020 |
Abdarainurus (meaning "Abdrant Nuru tail" after the holotype locality) is a genus of titanosaur dinosaur from the Alagteeg Formation in Mongolia. The type and only species is A. barsboldi. Currently seen as an indeterminate titanosaur, it may represent a previously unknown lineage of Asian macronarians. [1] Abdarainurus is not known from many remains; it is only known from eight front tail vertebrae and a middle tail vertebra and several chevrons.
The holotype, PIN 5669/1, was discovered in 1970 in Abdrant Nuru, hence the genus name, during a Joint Soviet–Mongolian Paleontological expedition and was excavated by V. P. Tverdokhlebov of Saratov State University. The fossils were left unprepared until at least 2000, when paleontologist Andrei Podlesnow revealed that they probably belonged to a new genus of sauropod. [2] The species Abdarainurus barsboldi was named in February 2020. [1]
Abdarainurus was discovered in the Abdarant Nuru locality of the Alagteeg Formation (which may be the same unit as the overlying Djadochta Formation) [3] of Mongolia [1] and coexisted with the ankylosaur Pinacosaurus sp., and indeterminate turtles and dinosaurs.
Abdarainurus was added to the phylogenetic analysis of Mannion and colleagues by Averianov and Lopatin, who ran the matrix under three different conditions. With all characters treated as equally important, Abdarainurus resolved as a non-titanosaur member of Somphospondyli, in a large polytomy with a variety of taxa. The more labile characters treated as slightly, or significantly, less important, Abdarainurus was either a basal titanosaur in a clade with Andesaurus and Huabeisaurus or as a member of Aeolosaurinae, respectively. As Abdarainurus was resolved with the fewest unique features as a basal titanosaur, Averianov and Lopatin suggested that phylogenetic result was the most likely, shown below. [1]
In their 2024 description of Gandititan , Han et al. recovered it as the sister taxon to Abdarainurus, in a clade of basal titanosaurs also including Andesaurus and Huabeisaurus , like the original analysis by Averianov & Lopatin (2020), in addition to Baotianmansaurus and Dongyangosaurus , which were recovered as part of a slightly more derived clade by Averianov & Lopatin (2020). [1] The results of their phylogenetic analyses are shown in the cladogram below: [4]
Nemegtosaurus was a sauropod dinosaur from the Late Cretaceous Period of what is now Mongolia. It was named after the Nemegt Basin in the Gobi Desert, where the remains — a single skull — were found. The skull resembles diplodocoids in being long and low, with pencil-shaped teeth. However, recent work has shown that Nemegtosaurus is in fact a titanosaur, closely related to animals such as Saltasaurus, Alamosaurus and Rapetosaurus.
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.
Patagonykus is a genus of theropod dinosaur from the Upper Cretaceous of Argentina. This alvarezsauroid was discovered in exposures of the Portezuelo Formation (Turonian-Coniacian) of the Rio Neuquén Subgroup in the Neuquén Basin, Neuquen Province of Patagonia, Argentina. The holotype consists of an incomplete but well-preserved skeleton, lacking a skull, but including many vertebrae, the coracoids, a partial forelimb, pelvic girdle, and hindlimbs. Patagonykus has been classed with the Alvarezsauridae, a family which includes such taxa as the Mongolian Mononykus and the Argentinian Alvarezsaurus. In 2010 Gregory S. Paul estimated its length at 1 meter and its weight at 3.5 kg.
Mongolosaurus is a genus of titanosauriform sauropod dinosaur which lived during the Early Cretaceous of China.
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.
The Alagteeg Formation is a geological formation in Mongolia whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation. It predominantly consists of alternating reddish brown mudstone and horizontally laminated sandstone, with ripple cross laminations and rhizoliths. It was first formally defined as a unit by Hasegawa et al. in 2008 as a distinct unit from the overlying Djadochta Formation. The environment of deposition is suggested to be fluvial, originating in sandy braided river, floodplain and ephemeral lake depositional environments, as opposed to the desert depositional environment of the Djadochta Formation.
Ruyangosaurus is a genus of titanosauriform sauropod dinosaur recovered from the Early Cretaceous Haoling Formation of China. The type species is R. giganteus, described in 2009 by Lü Junchang et al.
Wintonotitan is a genus of titanosauriform dinosaur from Cenomanian -age Winton Formation of Australia. It is known from partial postcranial remains.
Xianshanosaurus is a genus of sauropod dinosaur from the Early Cretaceous (Aptian-Albian) of the Ruyang Basin in Henan Province, China. Its type and only species is Xianshanosaurus shijiagouensis. It was described in 2009 by a team of paleontologists led by Lü Junchang. Xianshanosaurus may be a titanosaur, and Daxiatitan may be its closest relative, but its evolutionary relationships remain controversial.
Opisthocoelicaudiinae is a subfamily of titanosaurian dinosaurs from the Late Cretaceous. It was named by John McIntosh in 1990. Opisthocoelicaudiines are known from Mongolia, Argentina, and the United States. Two genera were assigned to Opisthocoelicaudiinae by Gonzalez et al. (2009): Alamosaurus and Opisthocoelicaudia, a conclusion also found by Díez Díaz et al. (2018). The hands of opisthocoelicaudiines lacked wrist bones and phalanges.
Bonapartenykus is a monospecific genus of alvarezsauroid dinosaur from Argentina that lived during the Late Cretaceous (Campanian-Maastrichtian) in what is now the upper Allen Formation of the Río Negro Province. The type and only species, Bonapartenykus ultimus, is known from a nearly articulated but partial skeleton that was found in close association to two incomplete eggs and several clusters of eggshells belonging to the oogenus Arriagadoolithus. Bonapartenykus was named in 2012 by Federico L. Agnolin, Jaime E. Powell, Fernando E. Novas and Martin Kundrát. Bonapartenykus has an estimated length of 2.5 m (8.2 ft) and weight of 72 kg (159 lb), making it the largest member of the clade Alvarezsauroidea.
Diamantinasauria is an extinct clade of somphospondylan titanosauriform sauropod dinosaurs with close affinities to the Titanosauria, known from the early Late Cretaceous (Cenomanian-Turonian) of South America and Australia. It was named by Poropat and colleagues in 2021, and contains four genera: Australotitan, Savannasaurus and Diamantinasaurus from the Winton Formation of Queensland, as well as Sarmientosaurus from the Bajo Barreal Formation of Patagonia. The existence of the clade indicates connectivity between Australia and South America via Antarctica during the Cretaceous period.
Dzharatitanis is a genus of sauropod from the Bissekty Formation in Uzbekistan, dating to the Turonian age of the Late Cretaceous. The genus contains a single species, Dzharatitanis kingi, named after geologist Christopher King, who contributed to the Cretaceous geology of Asia. It is currently one of two known sauropods from the Bissekty Formation, alongside an indeterminate titanosaur. In its original publication it was considered to be a member of Rebbachisauridae, but later papers considered it to be a titanosaur.
Khulsanurus is an extinct genus of alvarezsaurid theropod dinosaur from the Late Cretaceous Barungoyot Formation of the Khulsan Locality in the Gobi Desert region of Mongolia. The type and only species is Khulsanurus magnificus.
Rhomaleopakhus is a genus of mamenchisaurid sauropod, dinosaur from the Late Jurassic Kalaza Formation of China. The type and only species is Rhomaleopakhus turpanensis.
Ruixinia is an extinct genus of somphospondylan titanosauriform dinosaur from the Early Cretaceous (Barremian) Yixian Formation of China. The genus contains a single species, Ruixinia zhangi. The Ruixinia holotype is a partial articulated skeleton with the most complete series of caudal vertebrae known from any Asian titanosauriform.
Jiangxititan is an extinct genus of somphospondylan titanosauriform dinosaur from the Late Cretaceous Nanxiong Formation of China. The genus contains a single species, J. ganzhouensis, known from several articulated vertebrae with ribs. Originally described as a titanosaur, Jiangxititan was later suggested to be a non-titanosaurian somphospondylan.
Gandititan is an extinct genus of titanosaurian sauropod dinosaur from the Late Cretaceous Zhoutian Formation of China. The genus contains a single species, G. cavocaudatus, known from a partial skeleton.
Kiyacursor is an extinct genus of noasaurid theropod dinosaur from the Early Cretaceous Ilek Formation of Russia. The genus contains a single species, K. longipes, known from a partial skeleton. Kiyacursor represents the first Early Cretaceous ceratosaur discovered in Asia, as well as the second non-avian theropod named from Russia, after Kileskus in 2010.