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Stereognathus
''Stereognathus'' is an extinct genus of tritylodontid cynodonts from the Middle Jurassic of the United Kingdom. There is a single named species: ''S. ooliticus'', named after the Great Oolite deposits of England. A second species, ''S. hebridicus'', was named after the Hebrides in Scotland, where it was found; it was synonymized with ''S. ooliticus'' in 2017. Discovery and naming ''S. ooliticus'' was the first tritylodontid species ever found, being described by Charlesworth in 1855 and later by Sir Richard Owen. In 1972, ''S. hebridicus'' was named from several postcanine teeth recovered in Bathonian age deposits on the Isle of Skye in Scotland by palaeontologists R. J. G. Savage and Michael Waldman.Waldman, M and Savage, R.J.G 197The first Jurassic mammal from Scotland Journal of the Geological Society of London 128:119-125 Despite being the first tritylodontid genus found and named, ''Stereognathus'' remains poorly represented, being known mainly from isolated molar teeth. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montirictus
''Montirictus'' is an extinct genus of Tritylodontidae, tritylodonts known from the Early Cretaceous Kuwajima Formation of Japan. It is currently the latest surviving tritylodontid species, and is closely related to the earlier ''Xenocretosuchus'' from mainland Asia, and the Jurassic ''Stereognathus'' from the UK. It may be a species of the genus ''Stereognathus'', but resolution of its affinities conditions upon the discovery of additional material. References Prehistoric cynodont genera Fossil taxa described in 2016 Extinct animals of Japan Early Cretaceous synapsids Tritylodontids Fossils of Japan {{paleo-Therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritylodontidae
Tritylodontidae ("three-knob teeth", named after the shape of their cheek teeth) is an extinct family of small to medium-sized, highly specialized mammal-like cynodonts, bearing several mammalian traits like erect limbs, endothermy and details of the skeleton. They were the last-known family of the non-mammaliaform synapsids, persisting into the Early Cretaceous. Most tritylodontids are thought to have been herbivorous, feeding on vegetation, such as stems, leaves, and roots, although at least one may have had a more omnivorous diet. Tritylodontid fossils are found in the Americas, South Africa, and Eurasia—they appear to have had an almost global distribution, including Antarctica. Description The skull of tritylodontids had a high sagittal crest. They retained the primitive condition of the joint between the quadrate bone of the skull and the articular bone of the lower jaw—the retention of the joint is one of the reasons they are technically regarded to not be mam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritylodontids
Tritylodontidae ("three-knob teeth", named after the shape of their cheek teeth) is an extinct family of small to medium-sized, highly specialized mammal-like cynodonts, bearing several mammalian traits like erect limbs, endothermy and details of the skeleton. They were the last-known family of the non-mammaliaform synapsids, persisting into the Early Cretaceous. Most tritylodontids are thought to have been herbivorous, feeding on vegetation, such as stems, leaves, and roots, although at least one may have had a more omnivorous diet. Tritylodontid fossils are found in the Americas, South Africa, and Eurasia—they appear to have had an almost global distribution, including Antarctica. Description The skull of tritylodontids had a high sagittal crest. They retained the primitive condition of the joint between the quadrate bone of the skull and the articular bone of the lower jaw—the retention of the joint is one of the reasons they are technically regarded to not be mammals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polistodon
''Polistodon'' is an extinct genus of tritylodonts from the Bajocian or Callovian (Middle Jurassic) of China. It contains one species, ''P. chuannanensis'', which is known from a single skull from the Xiashaximiao Formation. According to one study, it may be a species of the genus ''Stereognathus ''Stereognathus'' is an extinct genus of tritylodontid cynodonts from the Middle Jurassic of the United Kingdom. There is a single named species: ''S. ooliticus'', named after the Great Oolite deposits of England. A second species, ''S. hebridic ...''. References Tritylodontids Prehistoric cynodont genera Bajocian genera Callovian genera Middle Jurassic synapsids of Asia Jurassic China Fossils of China Fossil taxa described in 1984 {{paleo-therapsid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenocretosuchus
''Xenocretosuchus'' is an extinct genus of tritylodont therapsids from the Aptian (Early Cretaceous) Ilek Formation of Siberia, in the Russian Federation. The type species, ''X. sibiricus'', is known only from dental elements, as is ''X. kolossovi'', described from the Batylykh Formation in 2008.Lopatin & Agadjanian, 2008. "A Tritylodont (Tritylodontidae, Synapsida) from the Mesozoic of Yakutia." Retrieved fro/ref> Some authors have treated these species as part of the genus ''Stereognathus,'' otherwise known from the Middle Jurassic of Britain But this is rejected by other authors. Alongside ''Montirictus'' and '' Fossiomanus'', it is amongst the latest known non-mammaliform-synapsid Synapsids + (, 'arch') > () "having a fused arch"; synonymous with ''theropsids'' (Greek, "beast-face") are one of the two major groups of animals that evolved from basal amniotes, the other being the sauropsids, the group that includes reptil ..., extending their range to the Early Cretaceous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathonian
In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Stratigraphic definitions The Bathonian Stage takes its name from Bath, a spa town in England built on Jurassic limestone (the Latinized form of the town name is ''Bathonium''). The name was introduced in scientific literature by Belgian geologist d'Omalius d'Halloy in 1843. The original type locality was located near Bath. The French palaeontologist Alcide d'Orbigny was in 1852 the first to define the exact length of the stage. The base of the Bathonian is at the first appearance of ammonite species '' Parkinsonia (Gonolkites) convergens'' in the stratigraphic column. The global reference profile for the base of the Bathonian (a GSSP) was ratified as Ravin du Bès, Bas-Auran area, Alpes de Haute Provence, France in 2009. The top of the Bat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barremian
The Barremian is an age in the geologic timescale (or a chronostratigraphic stage) between 129.4 ± 1.5 Ma (million years ago) and 121.4 ± 1.0 Ma). It is a subdivision of the Early Cretaceous Epoch (or Lower Cretaceous Series). It is preceded by the Hauterivian and followed by the Aptian Stage.See Gradstein ''et al.'' (2004) or the online geowhen database (link below) Stratigraphic definitions The original type locality for the Barremian Stage is in the vicinity of the village of Barrême, Alpes-de-Haute-Provence, France. Henri Coquand defined the stage and named it in 1873. The base of the Barremian is determined by the first appearance of the ammonites ''Spitidiscus hugii'' and ''Spitidiscus vandeckii''. The end of the Barremian is determined by the geomagnetic reversal at the start of the M0r chronozone, which is biologically near the first appearance of the ammonite '' Paradeshayesites oglanlensis''. Regional equivalents The Barremian falls in the Gallic epoch, a su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cynodont
The cynodonts () (clade Cynodontia) are a clade of eutheriodont therapsids that first appeared in the Late Permian (approximately 260 mya), and extensively diversified after the Permian–Triassic extinction event. Cynodonts had a wide variety of lifestyles, including carnivory and herbivory. Mammals are cynodonts, as are their extinct ancestors and close relatives, having evolved from advanced probainognathian cynodonts during the Late Triassic. All other cynodont lines went extinct, with the last known non-mammalian cynodont group, the Tritylodontidae, having its youngest records in the Early Cretaceous. Description Early cynodonts have many of the skeletal characteristics of mammals. The teeth were fully differentiated and the braincase bulged at the back of the head. Outside of some crown-group mammals (notably the therians), all cynodonts probably laid eggs. The temporal fenestrae were much larger than those of their ancestors, and the widening of the zygomatic arch in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations containing land animal fossils include the Forest Marble Formation in England, the Kilmaluag Formation in Scotland,British Geological Survey. 2011Stratigraphic framework for the Middle Jurassic strata of Great Britain and the adjoining continental shelf: research report RR/11/06 British Geological Survey, Keyworth, Nottingham. the Daohugou Beds in China, the Itat Formation in Russia, and the Isalo III Formation of western Madagascar. Paleogeography During the Middle Jurassic Epoch, Pangaea began to separate into Laurasia and Gondwana, and the Atlantic Ocean formed. Eastern Laurasia was tectonically active as the Cimmerian plate continued to collide with Laurasia's southern coast, completely closing the Paleo-Tethys Ocean. A subduction zone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Ireland, and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is , with an estimated 2020 population of more than 67 million people. The United Kingdom has evolved from a series of annexations, unions and separations of constituent countries over several hundred years. The Treaty of Union between the Kingdom of England (which included Wales, annexed in 1542) and the Kingdom of Scotland in 170 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Oolite
The Great Oolite Group is a Middle Jurassic stratigraphic unit that outcrops in southern England. It consists of a complex set of marine deposits primarily mudstone and bioclastic ooidal and fine grained limestone, deposited in nearshore to shelf settings. It is exposed at the surface as a variably thick belt extending roughly NE-SW from the coast of Dorset up to the Humber. It is also present at depth in the Weald and Wessex Basins, as well as offshore. Several of the constituent formations, notably the Taynton Limestone Formation and the Forest Marble Formation are notable for their fossil content, including those of dinosaurs and pterosaurs and some of the earliest mammals. Paleofauna * '' Cardiodon rugulosus'' * ''Cetiosaurus oxoniensis'' * '' Eoplophysis vetustus'' (stegosaurid indet) * ''Megalosaurus bucklandii'' * ''Proceratosaurus bradleyi'' * '' Seldsienean megistorhynchus'' See also * List of dinosaur-bearing rock formations ** List of stratigraphic units with f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebrides
The Hebrides (; gd, Innse Gall, ; non, Suðreyjar, "southern isles") are an archipelago off the west coast of the Scottish mainland. The islands fall into two main groups, based on their proximity to the mainland: the Inner and Outer Hebrides. These islands have a long history of occupation (dating back to the Mesolithic period), and the culture of the inhabitants has been successively influenced by the cultures of Celtic-speaking, Norse-speaking, and English-speaking peoples. This diversity is reflected in the various names given to the islands, which are derived from the different languages that have been spoken there at various points in their history. The Hebrides are where much of Scottish Gaelic literature and Gaelic music has historically originated. Today, the economy of the islands is dependent on crofting, fishing, tourism, the oil industry, and renewable energy. The Hebrides have less biodiversity than mainland Scotland, but a significant number of seals an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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