Arackar | |
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Model, next to one of Saltasaurus (from the Carnegie collection), and remains of Arackar licanantay, presented in the Museo Nacional de Historia Natural (MNHN) from Chile | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | † Sauropodomorpha |
Clade: | † Sauropoda |
Clade: | † Macronaria |
Clade: | † Titanosauria |
Clade: | † Lithostrotia |
Genus: | † Arackar Rubilar-Rogers et al., 2021 |
Species: | †A. licanantay |
Binomial name | |
†Arackar licanantay Rubilar-Rogers et al., 2021 | |
Arackar (meaning "skeleton" in Kunza [1] ) is an extinct genus of lithostrotian sauropod, possibly part of the Saltasauridae, discovered in the Hornitos Formation of Atacama Province, Chile. The genus contains a single species, Arackar licanantay, described by Rubilar-Rogers et al. in 2021. [2]
The holotype was discovered in 1993 at Quebrada La Higuera, approximately 75 km (47 mi) south of Copiapó. The fossil material was briefly mentioned by Rubilar-Rogers & Gutstein in 2012 and was found to not be referable to the genus Atacamatitan . [3] In 2021, Arackar licanantay was named and described by David Rubilar-Rogers, Alexander O. Vargas, Bernardo González Riga, Sergio Soto-Acuña, Jhonatan Alarcón-Muñoz, José Iriarte-Díaz, Carlos Arévalo and Carolina S. Gutstein. [2]
The holotype, SNGM-1, was found in a layer of the Hornitos Formation in Chile that dates back to the Late Cretaceous period (Campanian-Maastrichtian stages). It includes vertebrae of the neck and back, as well as a humerus, femur and ischium. It belonged to a juvenile and is currently the most complete specimen of a sauropod found in Chile. [2]
The full binomial name, Arackar licanantay, translates to "bones of the Atacamans" in the Kunza language.
The holotype represents a small individual with a body length estimated at around 6.3 metres (21 ft) long. [2] The size of a fully grown Arackar is unknown.
Some distinctive features have been identified by Ruilar-Rogers et al.. [2] The hollowing out between the front joint process and the vertebral body is high and wide. The hollowing out between the parapophysis and the lamina between the front joint process and the vertebral body extends over the entire front of the pedestal of the neural arch but not above the spinal canal. The posterior joint processes are narrower than the neural spine. The ridges between the neural spine and the posterior joint processes are reduced and shorter than the facet of the posterior joint process. [2]
Arackar was placed in the Titanosauria within the Lithostrotia in 2021, as a sister taxon of Isisaurus . Together, they form a sister clade to Rapetosaurus , within the Lithostrotia. The cladogram from Rubilar-Rogers et al. (2021) is shown below: [2]
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.
Secernosaurus is a genus of herbivorous dinosaur. Secernosaurus was a hadrosaur, a "duck-billed" dinosaur which lived during the Late Cretaceous.
Huabeisaurus was a genus of dinosaur from the Late Cretaceous. It was a sauropod which lived in what is present-day northern China. The type species, Huabeisaurus allocotus, was first described by Pang Qiqing and Cheng Zhengwu in 2000. Huabeisaurus is known from numerous remains found in the 1990s, which include teeth, partial limbs and vertebrae. Due to its relative completeness, Huabeisaurus represents a significant taxon for understanding sauropod evolution in Asia. Huabeisaurus comes from Kangdailiang and Houyu, Zhaojiagou Town, Tianzhen County, Shanxi province, China. The holotype was found in the unnamed upper member of the Huiquanpu Formation, which is Late Cretaceous (?Cenomanian–?Campanian) in age based on ostracods, charophytes, and fission-track dating.
Isisaurus is a genus of titanosaurian dinosaur from the Late Cretaceous Lameta Formation of India and Pab Formation of Pakistan. The genus contains a single species, Isisaurus colberti.
Antarctopelta is a genus of ankylosaurian dinosaur, a group of large, quadrupedal herbivores, that lived during the Maastrichtian stage of the Late Cretaceous period on what is now James Ross Island, Antarctica. Antarctopelta is the only known ankylosaur from Antarctica and a member of Parankylosauria. The only described specimen was found in 1986, the first dinosaur to be found on the continent, by Argentine geologists Eduardo Olivero and Robert Scasso. The fossils were later described in 2006 by paleontologists Leonardo Salgado and Zulma Gasparini, who named the type species A. oliveroi after Olivero.
Neuquensaurus is a genus of saltasaurid sauropod dinosaur that lived in the Late Cretaceous, about 80 million years ago in Argentina in South America. Its fossils were recovered from outcrops of the Anacleto Formation around Cinco Saltos, near the Neuquén river from which its name is derived.
Pellegrinisaurus is a genus of titanosaurian sauropod dinosaur that lived in South America during the Late Cretaceous period. The holotype was found in the Allen Formation, Argentina.
Puertasaurus is a genus of sauropod dinosaur that lived in South America during the Late Cretaceous Period. It is known from a single specimen recovered from sedimentary rocks of the Cerro Fortaleza Formation in southwestern Patagonia, Argentina, which probably is Campanian or Maastrichtian in age. The only species is Puertasaurus reuili. Described by the paleontologist Fernando Novas and colleagues in 2005, it was named in honor of Pablo Puerta and Santiago Reuil, who discovered and prepared the specimen. It consists of four well-preserved vertebrae, including one cervical, one dorsal, and two caudal vertebrae. Puertasaurus is a member of Titanosauria, the dominant group of sauropods during the Cretaceous.
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.
Diamantinasaurus is a genus of titanosaurian sauropod from Australia that lived during the early Late Cretaceous, about 94 million years ago. The type species of the genus is D. matildae, first described and named in 2009 by Scott Hocknull and colleagues based on fossil finds in the Winton Formation. Meaning "Diamantina lizard", the name is derived from the location of the nearby Diamantina River and the Greek word sauros, "lizard". The specific epithet is from the Australian song Waltzing Matilda, also the locality of the holotype and paratype. The known skeleton includes most of the forelimb, shoulder girdle, pelvis, hindlimb and ribs of the holotype, and one shoulder bone, a radius and some vertebrae of the paratype.
The Hornitos Formation is a Campanian geologic formation of the Algarrobal Basin in the Atacama Region of northern Chile. The formation comprises limestones, sandstones, conglomerates, marls and tuff. Dinosaur remains are among the fossils that have been recovered from the formation, including the sauropod Arackar licanantay.
Atacamatitan is a genus of titanosaurian sauropod dinosaurs from the Late Cretaceous Tolar Formation of Chile.
Bonapartesaurus is an extinct genus of herbivorous ornithopod dinosaur belonging to Hadrosauridae, which lived in the area of modern Argentina during the Campanian and Maastrichtian stages of the Late Cretaceous.
Mnyamawamtuka is a genus of lithostrotian titanosaur sauropod dinosaur from the Cretaceous Galula Formation in Tanzania. The type and only species is M. moyowamkia.
The Dorotea Formation is a geological formation in the Río de Las Chinas Valley of the Magallanes Basin in Patagonian Chile whose strata date back to the Campanian to Maastrichtian of the Late Cretaceous.
Stegouros is a genus of ankylosaurian dinosaur from the Late Cretaceous Dorotea Formation of southern Chile. The genus contains a single species, Stegouros elengassen, known from a semi-articulated, near-complete skeleton.
Huallasaurus is an extinct genus of saurolophine hadrosaur from the Late Cretaceous Los Alamitos Formation of Patagonia in Argentina. The type and only species is H. australis. Originally named as a species of Kritosaurus in 1984, it was long considered a synonym of Secernosaurus before being recognized as its own distinct genus in a 2022 study, different from other members of Kritosaurini.
Kelumapusaura is a genus of saurolophine hadrosaur from the Late Cretaceous Allen Formation in what is now Patagonia in Argentina. The type and only species is K. machi, known from a bonebed of various individuals.
Gonkoken is an extinct genus of hadrosauroid ornithopod dinosaur from the Late Cretaceous Dorotea Formation of Chilean Patagonia. The genus contains a single species, G. nanoi, known from disarticulated bones of multiple individuals.