Dinosaurus Temporal range: ~ | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Synapsida |
Clade: | Therapsida |
Genus: | † Dinosaurus Fischer, 1847 |
Species: | †D. murchisonii |
Binomial name | |
†Dinosaurus murchisonii (Fischer, 1845) | |
Dinosaurus is an extinct genus of therapsid of controversial affinities. Its type and only species is Dinosaurus murchisonii. It is only known from a partial snout from the Permian of Russia. Its taxonomic history is intertwined with several other poorly-known Russian therapsids, particularly Rhopalodon , Brithopus , and Phthinosuchus .
Dinosaurus is not a dinosaur; the similarity in names is coincidental. Dinosaurs belong to the clade Dinosauria, a clade of reptiles, whereas Dinosaurus is a therapsid, and as such, more closely related to mammals. Dinosauria was named only five years prior to Dinosaurus, in 1842. Dinosaurus also lived in the Permian period, which is part of the Paleozoic era, before dinosaurs existed, the first dinosaurs appeared in the following Triassic period of the Mesozoic era.
The holotype of Dinosaurus murchisonii was collected in a copper mine in the Orenburg Governorate of the Russian Empire during the 1840s. [2] It was collected in two pieces, found on separate occasions. The director of the mine, Wagenheim von Qualen, initially identified the first piece as a plant fossil in a letter to Johann Fischer von Waldheim, but Fischer realized it was part of a skull and described it as a new species of Rhopalodon, R. murchisonii, in 1845. [3] In 1847, Fischer described the second piece and established a new genus, Dinosaurus, for the species. In 1848, Eichwald recognized that the two specimens were not only from the same species, but fit together as parts of the same individual. He provisionally returned the species to Rhopalodon, as he felt there were not enough differences yet identified to justify a second genus, and noted the existence of the similarly-named taxon Dinosauria, named by Richard Owen only a few years prior, in 1842. [4]
Wagenheim von Qualen donated both specimens to the collection of Maximilian de Beuharnais, Duke of Leuchtenberg, and the originals have since been lost. However, casts of the specimens are housed in the Paleontological Institute, Russian Academy of Sciences under the catalog numbers PIN 296/1 and PIN 296/2.
In 1894, H. G. Seeley remarked that Cliorhizodon, which is now regarded as a junior synonym of Syodon , [5] could not be distinguished from Dinosaurus. [6] In 1954, Ivan Efremov synonymized Dinosaurus with Brithopus . This has been followed by some other authors, [7] but Christian Kammerer has regarded Brithopus, which is based on only a partial humerus, as a nomen dubium , and as such did not regard Dinosaurus as synonymous with it.
In 2000, M. F. Ivakhnenko synonymized Phthinosuchus with Dinosaurus. [8] As such, he classified Dinosaurus in the family Phthinosuchidae, which he grouped with Rubidgeidae [a] in the superfamily Rubidgeoidea of the order Gorgonopia. [10] Kammerer has remarked that the limited anatomical information available for Dinosaurus makes it hard to confirm this proposed synonymy. [11]
Dinocephalians are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. Dinocephalians included herbivorous, carnivorous, and omnivorous forms. Many species had thickened skulls with many knobs and bony projections. Dinocephalians were the first non-mammalian therapsids to be scientifically described and their fossils are known from Russia, China, Brazil, South Africa, Zimbabwe, and Tanzania.
Biarmosuchus is an extinct genus of biarmosuchian therapsids that lived around 267 mya during the Middle Permian period. Biarmosuchus was discovered in the Perm region of Russia. The first specimen was found in channel sandstone that was deposited by flood waters originating from the young Ural Mountains.
Deuterosaurus is an extinct genus of dinocephalian therapsids, one of the non-mammalian synapsids dominating the land during the late Paleozoic.
Biarmosuchia is an extinct clade of non-mammalian synapsids from the Permian. Biarmosuchians are the most basal group of the therapsids. They were moderately-sized, lightly built carnivores, intermediate in form between basal sphenacodont "pelycosaurs" and more advanced therapsids. Biarmosuchians were rare components of Permian ecosystems, and the majority of species belong to the clade Burnetiamorpha, which are characterized by elaborate cranial ornamentation.
Inostrancevia is an extinct genus of large carnivorous therapsids which lived during the Late Permian in what are now Siberia, Russia and Southern Africa. The first-known fossils of this gorgonopsian were discovered in the Northern Dvina, where two almost complete skeletons were exhumed. Subsequently, several other fossil materials were discovered in various oblasts, and these finds will lead to a confusion about the exact number of valid species in the country, before only three of them were officially recognized: I. alexandri, I. latifrons and I. uralensis. More recent research carried out in South Africa has discovered fairly well-preserved remains of the genus, being attributed to the species I. africana. An isolated left premaxilla suggests that Inostrancevia also lived in Tanzania during the earliest Lopingian age. The whole genus is named in honor of Alexander Inostrantsev, professor of Vladimir P. Amalitsky, the paleontologist who described the taxon.
Estemmenosuchus is an extinct genus of large, early omnivorous therapsid. It is believed and interpreted to have lived during the middle part of the Middle Permian around 267 million years ago. The two species, E. uralensis and E. mirabilis, are characterised by distinctive horn-like structures, which were probably used for intra-specific display. Both species of Estemmenosuchus are from the Perm region of Russia. Two other estemmenosuchids, Anoplosuchus and Zopherosuchus, are now considered females of the species E. uralensis. There were many complete and incomplete skeletons found together.
Rhopalodon is an extinct genus of therapsids from the Permian of Russia. It has been variously classified as a dinosaur, a dinocephalian, or another branch of amniotes. Rhopalodon is notable for being among the first "reptiles" mentioned in Nature. T.H. Huxley wrote of this animal, among others, in the inaugural issue of the magazine, in November 1869. He gave the age of this animal and of the contemporary Deuterosaurus as Triassic, but both are now known to have lived during the Middle Permian.
Dinogorgon is a genus of gorgonopsid from the Late Permian of South Africa and Tanzania. The generic name Dinogorgon is derived from Greek, meaning "terrible gorgon", while its species name rubidgei is taken from the surname of renowned Karoo paleontologist, Professor Bruce Rubidge, who has contributed to much of the research conducted on therapsids of the Karoo Basin. The type species of the genus is D. rubidgei.
Brithopus is an extinct genus of dinocephalian therapsids. It contains a single species, Brithopus priscus, known from fragmentary remains found in the Copper Sandstones near Isheevo, Russia.
Rubidgea is a genus of gorgonopsian from the upper Permian of South Africa and Tanzania, containing the species Rubidgea atrox. The generic name Rubidgea is sometimes believed to be derived from the surname of renowned Karoo paleontologist, Professor Bruce Rubidge, who has contributed to much of the research conducted on therapsids of the Karoo Basin. However, this generic name was actually erected in honor of Rubidge's paternal grandfather, Sidney Rubidge, who was a renowned fossil hunter. Its species name atrox is derived from Latin, meaning “fierce, savage, terrible”. Rubidgea is part of the gorgonopsian subfamily Rubidgeinae, a derived group of large-bodied gorgonopsians restricted to the Late Permian (Lopingian). The subfamily Rubidgeinae first appeared in the Tropidostoma Assemblage Zone. They reached their highest diversity in the Cistecephalus and Daptocephalus assemblage zones of the Beaufort Group in South Africa.
Microurania is an extinct genus of therapsids from the Middle Permian first named and described by Mikhaïl Ivakhnenko. It is known from a single partial skull found in the region of Orenburg, Russia. According to Kammerer, 2011, it likely represents the remains of a juvenile dinocephalian.
Scylacops is an extinct genus of Gorgonopsia. It was first named by Broom in 1913, and contains two species, S. bigendens, and S. capensis. Its fossils have been found in South Africa and Zambia. It is believed to be closely related to the Gorgonopsian Sauroctonus progressus. Scylacops was a moderately sized Gorgonopsid.
Venyukovia is an extinct genus of venyukovioid therapsid, a basal anomodont from the Middle Permian of Russia. The type and sole species, V. prima, is known only by a partial lower jaw with teeth. Venyukovia has often been incorrectly spelt as 'Venjukovia' in English literature. This stems from a spelling error made by Russian palaeontologist Ivan Efremov in 1940, who mistakenly replaced the 'y' with a 'j', which subsequently permeated through therapsid literature before the mistake was caught and corrected. Venyukovia is the namesake for the Venyukovioidea, a group of small Russian basal anomodonts also including the closely related Otsheria, Suminia, Parasuminia and Ulemica, although it itself is also one of the poorest known. Like other venyukovioids, it had large projecting incisor-like teeth at the front and lacked canines, although the remaining teeth are simple compared to some other venyukovioids, but may resemble those of Otsheria.
Eurosaurus is an extinct genus of non-mammalian synapsids. Its taxonomic history is intertwined with that of the therapsids Brithopus and Orthopus and the temnospondyl Melosaurus.
Niaftasuchus is an extinct genus of therapsids. Its type and only named species is Niaftasuchus zekkeli.
Venyukovioidea is an infraorder of anomodont therapsids related to dicynodonts from the Permian of Russia. They have also been known as 'Venjukovioidea', as well as by the similar names 'Venyukoviamorpha' or 'Venjukoviamorpha' in literature. This in part owes to a misspelling by Russian palaeontologist Ivan Efremov in 1940 when he mistakenly spelt Venyukovia, the namesake of the group, with a 'j' instead of a 'y', which permeated through subsequent therapsid literature before the mistake was caught and corrected. The order Ulemicia has also been coined for a similar taxonomic concept in Russian scientific literature, which notably excludes Suminia and Parasuminia.
Phthinosuchia is an extinct group of therapsids including two poorly known species, Phthinosuchus discors and Phthinosaurus borrisiaki, from the Middle Permian of Russia. Phthinthosuchus is known a partial crushed skull and Phthinosaurus is known from an isolated lower jaw. The two species have traditionally been grouped together based on their shared primitive characteristics, but more recent studies have proposed that they are more distantly related. Phthinosuchus is either a carnivorous gorgonopsian relative or an anteosaurian dinocephalian while Phthinosaurus is either a herbivorous rhopalodont dinocephalian or a therocephalian.
Phthinosaurus is an extinct genus of therapsids from the Middle Permian of Russia. The type species Phthinosaurus borrisiaki was named by Soviet paleontologist Ivan Yefremov in 1940 on the basis of an isolated lower jaw. Because this jaw provides few distinguishing characteristics, the evolutionary relationships of Phthinosaurus are poorly known. Yefremov named the family Phthinosuchidae in 1954 to include Phthinosaurus and the newly named Phthinosuchus, which was described on the basis of a crushed partial skull. American paleontologist Everett C. Olson placed both of these therapsids in the larger infraorder Phthinosuchia in 1961. In 1974 Leonid Tatarinov named the family Phthinosauridae to include Phthinosaurus alone, retaining Phthinosuchus within Phthinosuchidae.
Leogorgon is an extinct genus of dubious therapsid from the Late Permian Sokolki Faunal Assemblage of Russia. It was originally classified as a rubidgeine gorgonopsian, and would have been the first member of that clade from outside of Africa if that identification had been valid. However, it may instead be a combination of the tooth of a gorgonopsian and the braincase of a dicynodont, and may be a wastebin taxon.