Seitaad Temporal range: Early Jurassic, | |
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Skeletal reconstruction | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Dinosauria |
Clade: | Saurischia |
Clade: | † Sauropodomorpha |
Clade: | † Sauropodiformes |
Genus: | † Seitaad Sertich & Loewen, 2010 |
Species: | †S. ruessi |
Binomial name | |
†Seitaad ruessi Sertich & Loewen, 2010 | |
Seitaad is a genus of sauropodomorph dinosaur which lived during the Early Jurassic period in what is now southern Utah, United States. [1]
Seitaad is known from an articulated partial postcranial holotype skeleton referred to as UMNH VP 18040. The skeleton is missing its head, neck and tail. It was collected from the Lower Jurassic Navajo Sandstone, the uppermost unit of the Glen Canyon Group, dating to the Pliensbachian stage, near Comb Ridge, San Juan County. A phylogenetic study of Seitaad found it to be a plateosaur sauropodomorph, placing it in Massospondylidae or alternatively (a less probable position) in Plateosauridae, but its placement within the Plateosauria is not well understood. [1] In a cladistic analysis, presented by Apaldetti and colleagues in November 2011, Seitaad was found to be within Massopoda, just outside Anchisauria. [2]
Seitaad was first described by Joseph J. W. Sertich and Mark A. Loewen in 2010 and the type species is Seitaad ruessi. The generic name is derived from Séít‘áád (Navajo language), a mythological sand monster from the Diné folklore who buried its victims in dunes. Seitaad appears to have been entombed by the collapse of a sand dune. The specific name honours Everett Ruess, a young artist, poet and naturalist, who mysteriously disappeared in 1934 while exploring southern Utah. [1] Seitaad is the second basal sauropodomorph dinosaur to have been identified in North America. [3]
Eoraptor is a genus of small, lightly built, basal sauropodomorph dinosaur. One of the earliest-known dinosaurs and one of the earliest members of the sauropod family, 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. Eoraptor was 1.5 feet tall and 3 feet long.
Saturnalia is an extinct genus of basal sauropodomorph dinosaur known from the Late Triassic Santa Maria Formation of Rio Grande do Sul, southern Brazil.
Vulcanodon is an extinct genus of sauropod dinosaur from the Early Jurassic of southern Africa. The only known species is V. karibaensis. Discovered in 1969 in Zimbabwe, it was regarded as the earliest-known sauropod for decades, and is still one of the most primitive sauropods that has been discovered. As a quadrupedal, ground-dwelling herbivore, Vulcanodon already showed the typical sauropod body plan with column-like legs and a long neck and tail. It was smaller than most other sauropods, measuring approximately eleven metres (36 ft) in length. Vulcanodon is known from a fragmentary skeleton including much of the pelvic girdle, hindlimbs, forearms, and tail, but lacking the trunk and neck vertebrae as well as the skull.
Guaibasaurus is an extinct genus of basal saurischian dinosaur known from the Late Triassic Caturrita Formation of Rio Grande do Sul, southern Brazil. Most analyses recover it as a sauropodomorph, although there are some suggestions that it was a theropod instead. In 2016 Gregory S. Paul estimated it at 2 meters and 10 kg, whereas in 2020 Molina-Pérez and Larramendi listed it at 3 meters and 35 kg.
Lessemsaurus is an extinct genus of sauropod dinosaur belonging to Lessemsauridae.
The Navajo Sandstone is a geological formation in the Glen Canyon Group that is spread across the U.S. states of southern Nevada, northern Arizona, northwest Colorado, and Utah as part of the Colorado Plateau province of the United States.
Guanlong (冠龍) is a genus of extinct proceratosaurid tyrannosauroid dinosaur from the Late Jurassic of China. The taxon was first described in 2006 by Xu Xing et al., who found it to represent a new taxon related to Tyrannosaurus. The name is derived from Chinese, translating as "crown dragon". Two individuals are currently known, a partially complete adult and a nearly complete juvenile. These specimens come from the Oxfordian stage of the Chinese Shishugou Formation.
Bagaraatan is a genus of theropod dinosaur from the Late Cretaceous period. Its fossils were found in the Nemegt Formation of Mongolia. Bagaraatan may have been around 3 to 4 metres in length.
The Kayenta Formation is a geological formation in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. Traditionally has been suggested as Sinemurian-Pliensbachian, but more recent dating of detrital zircons has yielded a depositional age of 183.7 ± 2.7 Ma, thus a Pliensbachian-Toarcian age is more likely. A previous depth work recovered a solid "Carixian" age from measurements done in the Tenney Canyon. More recent works have provided varied datations for the layers, with samples from Colorado and Arizona suggesting 197.0±1.5-195.2±5.5 Ma, while the topmost section is likely Toarcian or close in age, maybe even recovering terrestrial deposits coeval with the Toarcian Oceanic Anoxic Event. This last age asignation also correlated the Toarcian Vulcanism on the west Cordilleran Magmatic Arc, as the number of grains from this event correlate with the silt content in the sandstones of the upper layers.
The Kaiparowits Formation is a sedimentary rock formation found in the Kaiparowits Plateau in Grand Staircase–Escalante National Monument, in the southern part of Utah in the western United States. It is over 2800 feet thick, and is Campanian in age. This Upper Cretaceous formation was formed from alluvial floodplains of large rivers in coastal southern Laramidia; sandstone beds are the deposit of rivers, and mudstone beds represent floodplain deposits. It is fossiliferous, with most specimens from the lower half of the formation, but exploration is only comparatively recent, with most work being done since 1982. It has been estimated that less than 10% of the Kaiparowits formation has been explored for fossils. Most fieldwork has been conducted by The Natural History Museum of Utah.
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. In 2019, a specimen previously assigned to Massospondylus from South Africa was re-examined and found to belong to a separate genus that was named Ngwevu.
Plateosauria is a clade of sauropodomorph dinosaurs which lived during the Late Triassic to the Late Cretaceous. The name Plateosauria was first coined by Gustav Tornier in 1913. The name afterwards fell out of use until the 1980s.
The Wahweap Formation of the Grand Staircase–Escalante National Monument is a geological formation in southern Utah and northern Arizona, around the Lake Powell region, whose strata date back to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.
Diabloceratops is an extinct genus of centrosaurine ceratopsian dinosaur that lived approximately 81.4-81 million years ago during the latter part of the Cretaceous Period in what is now Utah, in the United States. Diabloceratops was a medium-sized, moderately built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated 4.5 metres (15 ft) in length and 1.3 metric tons in body mass. At the time of its discovery, it was the oldest-known ceratopsid, and first centrosaurine known from latitudes south of the U.S. state of Montana. The generic name Diabloceratops means "devil-horned face," coming from Diablo, Spanish for "devil," and ceratops, Latinized Greek for "horned face." The specific name honors Jeffrey Eaton, a paleontologist at Weber State University and long time friend of the lead author Jim Kirkland. Eaton had a big role in establishing the Grand Staircase-Escalante National Monument where the specimen was found. The type species, Diabloceratops eatoni, was named and described in 2010 by James Ian Kirkland and Donald DeBlieux.
Ignavusaurus is a genus of basal sauropodomorph dinosaur that lived during the Early Jurassic in what is now Lesotho. Its fossils were found in the Upper Elliot Formation which is probably Hettangian in age. It was described on the basis of a partial, well preserved articulated skeleton. The type species, I. rachelis, was described in 2010 by Spanish palaeontologist F. Knoll.
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.
Sarahsaurus is a genus of basal sauropodomorph dinosaur which lived during the Early Jurassic period in what is now northeastern Arizona, United States.
Leyesaurus is an extinct genus of massospondylid sauropodomorph dinosaur known from the San Juan Province, northwestern Argentina.
The year 2011 in Archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2011 in paleontology included various significant developments regarding archosaurs.
The year 2010 in Archosaur paleontology was eventful. Archosaurs include the only living dinosaur group — birds — and the reptile crocodilians, plus all extinct dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosaur palaeontology is the scientific study of those animals, especially as they existed before the Holocene Epoch began about 11,700 years ago. The year 2010 in paleontology included various significant developments regarding archosaurs.