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Cyrtlatherium
''Cyrtlatherium'' is a dubious genus of extinct docodontan mammaliaform from the Middle Jurassic rocks of Oxfordshire, England. As it is only known from a few isolated molar teeth, there is disagreement about whether ''Cyrtlatherium'' is a separate genus, or whether it is a synonym and the molar teeth are the milk teeth of another genus of docodont. ''Cyrtlatherium'' was named from a few single molar teeth found in the Kirtlington Kirtlington is a village and Civil parishes in England, civil parish in Oxfordshire about west of Bicester. The parish includes the Hamlet (place), hamlet of Northbrook. The United Kingdom Census 2011, 2011 Census recorded the parish's populat ... mammal beds in England, which were originally thought to belong to a kuehneotheriid,Freeman EF. 1979. A Middle Jurassic mammal bed from Oxfordshire. Palaeontology 22:135-166 but were later reclassified as belonging to a docodont.Sigogneau-Russell D. 200Docodont nature of Cyrtlatherium, an upper Bathoni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docodonta
Docodonta is an Order (biology), order of extinct Mammaliaformes, mammaliaforms that lived during the Mesozoic, from the Middle Jurassic to Early Cretaceous. They are distinguished from other early Mammaliaformes, mammaliaforms by their relatively complex Molar (tooth), molar teeth, from which the order gets its name. Until recently, Docodonta were represented primarily by teeth and jaws found across former Laurasia, (modern-day North America, Europe, and Asia). However, recent discoveries in China include some exceptionally well preserved, almost complete body fossils. Description Skeletal traits Docodonts have a long and low mandible (lower jaw), formed primarily by the tooth-bearing dentary bone. The dentary connects to the cranium via a joint with the Squamosal bone, squamosal, a connection which is strengthened relative to earlier mammaliaforms. The other bones in the jaw, known as postdentary elements, are still connected to the dentary and lie within a groove (the postd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docodonts
Docodonta is an order of extinct mammaliaforms that lived during the Mesozoic, from the Middle Jurassic to Early Cretaceous. They are distinguished from other early mammaliaforms by their relatively complex molar teeth, from which the order gets its name. Until recently, Docodonta were represented primarily by teeth and jaws found across former Laurasia, (modern-day North America, Europe, and Asia). However, recent discoveries in China include some exceptionally well preserved, almost complete body fossils. Description Skeletal traits Docodonts have a long and low mandible (lower jaw), formed primarily by the tooth-bearing dentary bone. The dentary connects to the cranium via a joint with the squamosal, a connection which is strengthened relative to earlier mammaliaforms. The other bones in the jaw, known as postdentary elements, are still connected to the dentary and lie within a groove (the postdentary trough) in the rear part of the dentary’s inner edge. Nevertheless, ... [...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] |
Mammaliaform
Mammaliaformes ("mammalian forms") is a clade that contains the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts. It is defined as the clade originating from the most recent common ancestor of Morganucodonta and the crown group mammals; the latter is the clade originating with the most recent common ancestor of extant Monotremata, Marsupialia, and Placentalia. Besides Morganucodonta and the crown group mammals, Mammaliaformes includes Docodonta and '' Hadrocodium'' as well as the Triassic ''Tikitherium'', the earliest known member of the group. Mammaliaformes is a term of phylogenetic nomenclature. In contrast, the assignment of organisms to Mammalia has traditionally been founded on traits and, on this basis, Mammalia is slightly more inclusive than Mammaliaformes. In particular, trait-based taxonomy generally includes ''Adelobasileus'' and ''Sinoconodon'' in Mammalia, though they fall outside the Mammaliaform ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxfordshire
Oxfordshire is a ceremonial and non-metropolitan county in the north west of South East England. It is a mainly rural county, with its largest settlement being the city of Oxford. The county is a centre of research and development, primarily due to the work of the University of Oxford and several notable science parks. These include the Harwell Science and Innovation Campus and Milton Park, both situated around the towns of Didcot and Abingdon-on-Thames. It is a landlocked county, bordered by six counties: Berkshire to the south, Buckinghamshire to the east, Wiltshire to the south west, Gloucestershire to the west, Warwickshire to the north west, and Northamptonshire to the north east. Oxfordshire is locally governed by Oxfordshire County Council, together with local councils of its five non-metropolitan districts: City of Oxford, Cherwell, South Oxfordshire, Vale of White Horse, and West Oxfordshire. Present-day Oxfordshire spanning the area south of the Thames was h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirtlington
Kirtlington is a village and civil parish in Oxfordshire about west of Bicester. The parish includes the hamlet of Northbrook. The 2011 Census recorded the parish's population as 988. The parish measures nearly north–south and about east–west. It is bounded by the River Cherwell to the west, and elsewhere mostly by field boundaries. In 1959 its area was . Archaeology The Portway is a pre-Roman road running parallel with the Cherwell on high ground about east of the river. It bisects Kirtlington parish and passes through the village. A short stretch of it is now part of the A4095 road through the village. Longer stretches form minor roads to Bletchingdon and Upper Heyford. Akeman Street Roman road bisects the parish east–west passing just north of Kirtlington village. A minor road linking Kirtlington with Chesterton uses its course. Aves ditch is pre-Saxon. One end of the ditch is in Kirtlington parish about north of the village. Just east of the parish school is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kuehneotheriid
Kuehneotheriidae is an extinct family of mammaliaforms traditionally placed within 'Symmetrodonta', though now generally considered more basal than true symmetrodonts. All members of Kuehneotheriidae which have been found so far are represented only by teeth, but these teeth have features which have led paleontologists to classify kuehneotheriids as very close relatives of the first true mammals. But fossil clades based solely on teeth often lead to difficulties (Ausktribosphenidae being a good example), and it is not possible to draw significant conclusions about mammalian evolution from Kuehneotheriidae unless some more complete skeletons are found. See also * Evolution of mammals The evolution of mammals has passed through many stages since the first appearance of their synapsid ancestors in the Pennsylvanian sub-period of the late Carboniferous period. By the mid-Triassic, there were many synapsid species that looked l ... References Prehistoric mammaliaforms Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simpsonodon
''Simpsonodon'' is an extinct genus of docodontan mammaliaform known from the Middle Jurassic of England, Kyrgyzstan and Russia. The type species ''S. oxfordensis'' was described from the Kirtlington Mammal Bed and Watton Cliff in the Forest Marble Formation of England. It was named after George Gaylord Simpson, a pioneering mammalologist and contributor to the Modern Evolutionary Synthesis. A second species ''S. sibiricus'' is known from the Itat Formation of Russia, and indeterminate species of the genus are also known from the Balabansai Formation in Kyrgyzstan Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ... References Docodonts Prehistoric cynodont genera Bathonian life Callovian life Middle Jurassic synapsids of Asia Middle Jurassic synapsids of Europe Jur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Synapsids Of Europe
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and is the only boundary between geological periods to remain formally undefined. By the beginning of the Jurassic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1979
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxa Named By Eric F
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in ''Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the intr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
