Gravisauria

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Gravisaurians
Temporal range: Early JurassicLate Cretaceous, 196.5–66  Ma
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Clade: Saurischia
Clade: Sauropodomorpha
Clade: Sauropoda
Clade: Gravisauria
Allain & Aquesbi, 2008
Subgroups [1]

Gravisauria is a clade of sauropod dinosaurs consisting of some genera, Vulcanodontidae and Eusauropoda. [2]

Contents

Classification

The clade Gravisauria was appointed by the French paleontologist Ronan Allain and Moroccan paleontologist Najat Aquesbi in 2008 when a cladistic analysis of the dinosaur found by Allain, Tazoudasaurus , as the outcome was that the family Vulcanodontidae. The group includes Tazoudasaurus and Vulcanodon, and the sister taxon Eusauropoda, but also certain species such as Antetonitrus , Gongxianosaurus and Isanosaurus that do not belong in Vulcanodontidae but to an even more basic position occupied in Sauropoda. It made sense to have Sauropoda compared to this, more derived group that included Vulcanodontidae and Eusauropoda in a definition: Gravisauria (heavy lizards), defined as the group formed by the last common ancestor of Tazoudasaurus and Saltasaurus (Bonaparte and Powell, 1980) and all its descendants. [2]

Below is a cladogram found by Nair and Salisbury in 2012 showing the relationships of Gravisauria: [1]

Gravisauria

Vulcanodon

Tazoudasaurus

Spinophorosaurus

Barapasaurus

Rhoetosaurus

Eusauropoda

Shunosaurus

Patagosaurus

Omeisaurus

Mamenchisaurus

Turiasauria

Losillasaurus

Haplocanthosaurus

Neosauropoda

Synapomorphies

Aquesbi mentioned two synapomorphies, shared derived characteristics of Gravisauria: the vertebrae are wider side to side than front to rear and possession of asymmetrical condyles femoris at the bottom of the femur. Those were previously not thought to be Eusauropoda synapomorphies but Allian found these properties also on Tazoudasaurus . [2]

Involvement in extinction

Gravisauria split off in the Early Jurassic, around the Pliensbachian and Toarcian, 183 million years ago, and Aquesbi thought that this was part of a much larger revolution in the fauna, which includes the disappearance of Prosauropoda, Coelophysoidea and basal Thyreophora, which they attributed to a worldwide mass extinction. [2]

Related Research Articles

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Barapasaurus is a genus of basal sauropod dinosaur from Jurassic rocks of India. The only species is B. tagorei. Barapasaurus comes from the lower part of the Kota Formation, which is of Early to Middle Jurassic age. It is therefore one of the earliest known sauropods. Barapasaurus is known from approximately 300 bones from at least six individuals, so that the skeleton is almost completely known except for the anterior cervical vertebrae and the skull. This makes Barapasaurus one of the most completely known sauropods from the early Jurassic.

<span class="mw-page-title-main">Titanosauria</span> Extinct clade of dinosaurs

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.

Jobaria is a genus of sauropod dinosaur that lived in what is now Niger during the middle Jurassic Period, between 164 and 161 million years ago. Jobaria is currently the only known valid sauropod from the Tiouraren, where it was discovered in 1997.

<span class="mw-page-title-main">Brachiosauridae</span> Extinct family of dinosaurs

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<i>Vulcanodon</i> Extinct genus of dinosaurs

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.

<span class="mw-page-title-main">Megalosauridae</span> Extinct family of dinosaurs

Megalosauridae is a monophyletic family of carnivorous theropod dinosaurs within the group Megalosauroidea. Appearing in the Middle Jurassic, megalosaurids were among the first major radiation of large theropod dinosaurs. They were a relatively primitive group of basal tetanurans containing two main subfamilies, Megalosaurinae and Afrovenatorinae, along with the basal genus Eustreptospondylus, an unresolved taxon which differs from both subfamilies.

<span class="mw-page-title-main">Macronaria</span> Extinct clade of dinosaurs

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<i>Tazoudasaurus</i> Extinct genus of dinosaurs

Tazoudasaurus is a genus of gravisaurian, probably a vulcanodontid sauropod dinosaurs hailing from the late Early Jurassic (Toarcian), that was recovered in the "Toundoute Continental Series" located in the High Atlas Mountains of Morocco in North Africa. Along with Patagosaurus, Volkheimeria, Bagualia and Perijasaurus represents one of the few sauropods named from this stage on Gondwana, as well the only one from Africa.

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<i>Ohmdenosaurus</i> Extinct species of reptile

Ohmdenosaurus is a genus of sauropod dinosaur that lived during the Early Jurassic epoch in what is now Germany. The only specimen – a tibia (shinbone) and ankle – was discovered in rocks of the Posidonia Shale near the village of Ohmden. The specimen, which was originally identified as a plesiosaur, is exhibited in a local museum, the Urweltmuseum Hauff. In the 1970s, it caught the attention of German palaeontologist Rupert Wild, who recognised it as the remains of a sauropod. Wild named Ohmdenosaurus in a 1978 publication; the only known species is Ohmdenosaurus liasicus.

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<span class="mw-page-title-main">Neosauropoda</span> Extinct clade of dinosaurs

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<span class="mw-page-title-main">Maniraptoriformes</span> Clade of dinosaurs

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<i>Berberosaurus</i> Extinct genus of dinosaurs

Berberosaurus is a genus of neotheropod dinosaur, possibly a ceratosaur, from the Toarcian-age "Toundoute Continental Series" found in the Central High Atlas of Toundoute, Ouarzazate, Morocco. The type species of the genus Berberosaurus is B. liassicus, in reference to the Lias epoch. Berberosaurus might be the oldest known ceratosaur, and is based on partial postcranial remains. This genus represents the oldest formally identified theropod from the North of Africa, as well one of the few from the region in the Early Jurassic.

<span class="mw-page-title-main">Massopoda</span> Extinct clade of dinosaurs

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<i>Spinophorosaurus</i> Middle Jurassic genus of sauropod dinosaur

Spinophorosaurus is a genus of sauropod dinosaur that lived in what is now Niger during the Middle Jurassic period. The first two specimens were excavated in the 2000s by German and Spanish teams under difficult conditions. The skeletons were brought to Europe and digitally replicated, making Spinophorosaurus the first sauropod to have its skeleton 3D printed, and were to be returned to Niger in the future. Together, the two specimens represented most of the skeleton of the genus, and one of the most completely known basal sauropods of its time and place. The first skeleton was made the holotype specimen of the new genus and species Spinophorosaurus nigerensis in 2009; the generic name refers to what was initially thought to be spiked osteoderms, and the specific name refers to where it was found. A juvenile sauropod from the same area was later assigned to the genus.

<span class="mw-page-title-main">Eusauropoda</span> Extinct clade of dinosaurs

Eusauropoda is a derived clade of sauropod dinosaurs. Eusauropods represent the node-based group that includes all descendant sauropods starting with the basal eusauropods of Shunosaurus, and possibly Barapasaurus, and Amygdalodon, but excluding Vulcanodon and Rhoetosaurus. The Eusauropoda was coined in 1995 by Paul Upchurch to create a monophyletic new taxonomic group that would include all sauropods, except for the vulcanodontids.

The Tilougguit Formation, also known as the Tillouguit Formation, is an Early Bathonian geologic formation in Morocco. An indeterminate sauropod is known from the formation

The El Mers Group is a geological group in the Middle Atlas of Morocco. It is subdivided into 3 formations named the El Mers 1, 2 and 3 Formations respectively. It is a marine deposit primarily consisting of marl, with gypsum present in the upper part of unit 3. and is the lateral equivalent of the terrestrial Guettioua Sandstone. Dinosaur remains are among the fossils that have been recovered from the group, most notably those of indeterminate theropods, the sauropod "Cetiosaurus" mogrebiensis, the stegosaur Adratiklit, the ankylosaur Spicomellus, the inchnofossil Selenichnites and an indeterminate teleosauroid.

References

  1. 1 2 Nair, J. P.; Salisbury, S. W. (2012). "New anatomical information on Rhoetosaurus brownei Longman, 1926, a gravisaurian sauropodomorph dinosaur from the Middle Jurassic of Queensland, Australia". Journal of Vertebrate Paleontology. 32 (2): 369. doi:10.1080/02724634.2012.622324.
  2. 1 2 3 4 5 Allain, R. and Aquesbi, N. (2008). "Anatomy and phylogenetic relationships of Tazoudasaurus naimi (Dinosauria, Sauropoda) from the late Early Jurassic of Morocco." Geodiversitas, 30(2): 345-424.