| Lametasaurus Temporal range: Late Cretaceous, | |
|---|---|
 | |
| Tibia from the holotype of L. indicus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Dinosauria |
| Genus: | † Lametasaurus Matley, 1923 |
| Type species | |
| †Lametasaurus indicus | |
Lametasaurus (lə-MAY-tə-SOR-us - meaning "Lameta lizard") named for the Lameta Formation, Jabalpur, India, is the generic name given to a possibly chimeric dinosaur species. [1] The type species is L. indicus.
Between October 1917 and 1919 Charles Alfred Matley excavated fossils near Jabalpur. [2] In 1921 he reported the find in the "Carnosaur Bed" of what he considered to be two megalosaurians, theropod dinosaurs. [3] In 1923/1924 he named one of these as the type species Lametasaurus indicus. The generic name refers to the Lameta Formation, dating from the Maastrichtian, the specific name refers to India. However, Matley no longer identified it as a theropod but as a member of the Stegosauria instead, which concept at the time also included the armoured dinosaurs today assigned to the Ankylosauria; at first Matley had seen it as a stegosaurian in the modern sense and even intended to name it as a species of Omosaurus . [2] The type specimen consisted of a number of dermal scutes, a sacrum of at least five sacral vertebrae, a pelvis, a tibia and teeth. [4] In 1933 Matley and Friedrich von Huene described some more remains collected by Barnum Brown, [2] thought to have been part of a tail club; [5] later this was shown to be a large osteoderm. [2]
However, in 1935 Dhirendra Kishore Chakravarti contested the interpretation as an armoured dinosaur. He claimed that the specimen was a chimera including titanosaurid armor, crocodile teeth and theropod hindlimb material. [6] In 1964 Alick Walker chose the scutes as the lectotype, thus removing the teeth and the bones from the type material. [7] The name Lametasaurus now designated the scutes only and was generally considered to represent a member of the Nodosauridae. The pelvis and hindlimb bones have in 2003 been suggested to belong to Rajasaurus, based on shared features in the ilium . [8] In 2008 Matthew Carrano e.a. discarded the possibility the scutes were ankylosaurian, stating they were probably titanosaurian, but noted that a comparison to the osteoderms of Ceratosaurus would help in determining its affinities. If in which case the species were to be found ceratosaurian, it would possibly be a senior synonym of Indosaurus and/or Rajasaurus. [9] Most recently, it has been suggested that some of the osteoderms assigned to Lametasaurus show ankylosaurian synapomorphies, [10] which renders Lametasaurus a chimera regardless of the affinities of the other material.
The type material has been lost, lacking a known inventory number, making it difficult to test the several hypotheses. The taxon is today commonly seen as a nomen dubium . [11]
Carnosauria is an extinct group of carnivorous theropod dinosaurs that lived during the Jurassic and Cretaceous periods.
Rajasaurus is a genus of carnivorous abelisaurid theropod dinosaur from the Late Cretaceous of India, containing one species: Rajasaurus narmadensis. The bones were excavated from the Lameta Formation in the Gujarat state of Western India, probably inhabiting what is now the Narmada River Valley. It was formally described by palaeontologist Jeffrey A. Wilson and colleagues in 2003 based on a partial skeleton comprising the braincase, spine, hip bone, legs, and tail–a first for an Indian theropod. The dinosaur likely measured 6.6 metres (22 ft), and had a single horn on the forehead which was probably used for display and head-butting. Like other abelisaurids, Rajasaurus was probably an ambush predator.
Scelidosaurus is a genus of herbivorous armoured ornithischian dinosaur from the Jurassic of England.
Jainosaurus is a genus of titanosaurian sauropod dinosaur of India and wider Asia, which lived in the Maastrichtian. It is thought to have been about the same size as its contemporary relative Isisaurus, measuring 18 metres (59 ft) long and weighing 15 metric tons. The humerus of the type specimen is 134 centimetres long.
Indosuchus is a genus of abelisaurid dinosaur from the Late Cretaceous Period, a theropod related to Abelisaurus. Like most theropods, Indosuchus was a bipedal carnivore. It was about 7 metres long, weighed about 1.2 tonnes, and had a crested skull, flattened on the top.
Abelisauridae is a family of ceratosaurian theropod dinosaurs. Abelisaurids thrived during the Cretaceous period, on the ancient southern supercontinent of Gondwana, and today their fossil remains are found on the modern continents of Africa and South America, as well as on the Indian subcontinent and the island of Madagascar. Isolated teeth were found in the Late Jurassic of Portugal, and the Late Cretaceous genera Tarascosaurus and Arcovenator have been described in France. Abelisaurids first appear in the fossil record of the early middle Jurassic period, and at least three genera survived until the end of the Mesozoic era 66 million years ago.
Deltadromeus is a genus of theropod dinosaur from the Aoufous Formation of Morocco.
Jeffrey A. Wilson, also known as JAW, is a paleontologist and professor of geological sciences and assistant curator at the Museum of Paleontology at the University of Michigan.
Brachypodosaurus is a dubious genus of dinosaur, possibly an ornithischian, from the Late Cretaceous Lameta Formation (Maastrichtian) in India.
Indosaurus is a genus of carnivorous theropod dinosaur that lived in what is now India, about 69 to 66 million years ago during the Maastrichtian division of the Late Cretaceous.
Coeluroides is an extinct genus of theropod dinosaur that lived during the Late Cretaceous Period in what is now India. It is based solely on the holotype caudal vertebrae GSI K27/562, K27/574 and K27/595, discovered in a layer of the Lameta Formation. The type species, C. largus, was described by Friedrich von Huene and Charles Alfred Matley in 1933.
Compsosuchus is a dubious genus of abelisauroid dinosaur from the Late Cretaceous Lameta Formation of India.
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.
Erectopus is an extinct genus of basal allosauroid theropod from the Early Cretaceous La Penthiève Beds Formation of France and also possibly the Cernavodă Formation of southern Romania. The type species is E. superbus, which was initially known as a species of Megalosaurus.
Laevisuchus is a genus of theropod dinosaur from the Late Cretaceous. Its remains were discovered by Charles Alfred Matley near Jabalpur in Maastrichtian "Carnosaur Bed" deposits in the Lameta Formation in Madhya Pradesh, central India, and were named and described by paleontologists Friedrich von Huene and Matley in 1933.
Orthogoniosaurus was a genus of theropod dinosaur from the late Maastrichtian-age Upper Cretaceous Lameta Formation of Jabalpur, India. It is based on one small, fragmentary tooth.
The Lameta Formation, also known as the Infratrappean Beds, is a sedimentary geological formation found in Madhya Pradesh, Gujarat, Maharashtra, Telangana, and Andhra Pradesh, India, associated with the Deccan Traps. It is of the Maastrichtian age, and is notable for its dinosaur fossils
Rahiolisaurus is a genus of abelisaurid theropod dinosaur which existed in India during the Late Cretaceous period. It was described in 2010, based on fossils recovered from the Lameta Formation in the Indian state of Gujarat. These fossils include elements from at least seven different individuals and are believed to have been from the Maastrichtian stage, sometime between 72.1 and 66 million years ago, making it one of the last non-avian dinosaurs known in the fossil record. Despite representing a variety of different growth stages, all recovered fossils from the locality indicate a single species, the type species Rahiolisaurus gujaratensis.
Majungasaurinae is a subfamily of large carnivorous theropods from the Upper Cretaceous, found in Madagascar, India, and France. It is a subgroup within the theropod family Abelisauridae, a Gondwanan clade known for their thick and often horned skulls and vestigial arms. The two subfamilies of Abelisauridae are Carnotaurinae, best known from the South American Carnotaurus, and Majungasaurinae, consisting of Madagascar’s Majungasaurus and its closest relatives. Their ancestors emerged in the Middle Jurassic, and the clade lasted until the Upper Cretaceous.
This timeline of ceratosaur research is a chronological listing of events in the history of paleontology focused on the ceratosaurs, a group of relatively primitive, often horned, predatory theropod dinosaurs that became the apex predators of the southern hemisphere during the Late Cretaceous. The nature and taxonomic composition of the Ceratosauria has been controversial since the group was first distinguished in the late 19th century. In 1884 Othniel Charles Marsh described the new genus and species Ceratosaurus nasicornis from the Late Jurassic Morrison Formation of the western United States. He felt that it belonged in a new family that he called the Ceratosauridae. He created the new taxon Ceratosauria to include both the Ceratosauridae and the ostrich-like ornithomimids. The idea of the Ceratosauria was soon contested, however. Later that same decade both Lydekker and Marsh's hated rival Edward Drinker Cope argued that the taxon was invalid.
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