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Amphitherium
''Amphitherium'' is an extinct genus of stem cladotherian mammal that lived during the Middle Jurassic of England. It was one of the first Mesozoic mammals ever described. A recent phylogenetic study found it to be the sister taxon of ''Palaeoxonodon''. It is found in the Forest Marble Formation and the Taynton Limestone Formation. Etymology ''Amphitherium'' comes from the Greek ''amphi'' meaning 'on both sides', and ''therion'' meaning 'wild beast'. This was in reference to de Blainville's incorrect belief that the original fossil jaw of this animal was not a mammal, but something in between mammals and reptiles. History The first jaws of mammals from the Mesozoic - including ''Amphitherium'' - were found in the Stonesfield Slate, part of the Taynton Limestone Formation near Stonesfield in England.Rudwick, M.J.S. 2008Worlds Before Adam/ref> These were bought by a student of the British paleontologist William Buckland. Although he thought the jaws were mammalian, the anatomis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphitheriida
Amphitheriidae is a family of Mesozoic mammals restricted to the Middle Jurassic of Britain, with indeterminate members also possibly known from the equivalently aged Itat Formation in Siberia and the Anoual Formation of Morocco. They were members of Cladotheria, more derived than members of Dryolestida, and forming a close relationship with Peramuridae.Panciroli E; Roger B.J. Benson; Richard J. Butler (2018).New partial dentaries of amphitheriid mammalian Palaeoxonodon ooliticus from Scotland, and posterior dentary morphology in early cladotherians. Acta Palaeontologica Polonica. in press. doi:10.4202/app.00434.2017. Amphitheriidae is the only family of the order Amphitheriida. Classification * Mammalia ** Yinotheria (monotremes and relatives) ** Theriimorpha ***†Eutriconodonta *** Theriiformes ****† Allotheria *****†Gondwanatheria *****† Multituberculata **** Trechnotheria ***** †Spalacotheriidae ***** †Zhangheotheriidae ***** Cladotheria ****** †Meridiole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphilestes
''Amphilestes'' is a genus of extinct eutriconodont mammal from the Middle Jurassic of the United Kingdom. It was one of the first Mesozoic mammals discovered and described. Discovery The first specimen of ''Amphilestes'' was discovered along with several other mammal jaws in the Stonesfield Slate Quarry, Oxfordshire before 1764.Kermack, KA. 1988 British Mesozoic mammal sites. ''Special Papers in Palaeontology'', 40:85-93. However, it was not until 1812 that William Broderip bought the jaws, and he and his mentor - the famous palaeontologist Revd William Buckland William Buckland DD, FRS (12 March 1784 – 14 August 1856) was an English theologian who became Dean of Westminster. He was also a geologist and palaeontologist. Buckland wrote the first full account of a fossil dinosaur, which he named ' ... - recognised that they were of mammal origin. ''Amphilestes broderipii'' was originally '' Amphitherium broderipii'', until it was recognised as a distinct and new spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phascolotherium
''Phascolotherium'' is a genus of extinct eutriconodont mammal from the Middle Jurassic of the United Kingdom. Found in the Stonesfield Slate, it was one of the first Mesozoic mammals ever found and described, although like the other mammal jaws found at the same time, it was mistakenly thought at first to be a marsupial.Broderip W.J. 1828. Observations on the jaw of a fossil mammiferous animal found in the Stonesfield Slate. Zoological Journal of London 3, 408–412 Discovery ''Phascolotherium'' was one of the first mammals described from Mesozoic-aged rocks. It is only known from single lower jaws and some isolated teeth. Buckland showed the fossil jaws of Stonesfield to the exceptional comparative anatomist, Georges Cuvier, who incorrectly identified them as marsupials, based on the similarity of the bones to modern marsupials. Blainville also attributed the fossil to his newly erected genus, Amphitherium. More than one specimen was given to Buckland, and one of these lower ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
Mammals () are a group of vertebrate animals constituting the class (biology), class Mammalia (), characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or hair, and three ossicles, middle ear bones. These characteristics distinguish them from reptiles (including birds) from which they Genetic divergence, diverged in the Carboniferous, over 300 million years ago. Around 6,400 extant taxon, extant species of mammals have been described divided into 29 Order (biology), orders. The largest Order (biology), orders, in terms of number of species, are the rodents, bats, and Eulipotyphla (hedgehogs, Mole (animal), moles, shrews, and others). The next three are the Primates (including humans, apes, monkeys, and others), the Artiodactyla (cetaceans and even-toed ungulates), and the Carnivora (cats, dogs, pinniped, seals, and others). In terms of cladistic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taynton Limestone Formation
The Taynton LimestoneWeishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 538–541. . is a geological formation in Oxfordshire in the United Kingdom. It dates to the Middle Jurassic, mid-Bathonian stage.Benson, R.B.J. (2009). "An assessment of variability in theropod dinosaur remains from the Bathonian (Middle Jurassic) of Stonesfield and New Park Quarry, UK and taxonomic implications for ''Megalosaurus bucklandii'' and ''Iliosuchus incognitus''." ''Palaeontology'', It predominantly consists of ooidal grainstone. The term "Stonesfield Slate" refers to slaty limestone horizons within the formation that during the 18th and 19th centuries were extensively quarried for use in roof tiling within the vicinity of Stonesfield, Oxfordshire. Previously these were thought to belong to the Sharp's Hill Formation, but bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoxonodon
''Palaeoxonodon'' is an extinct genus of Cladotherian mammal from the Middle Jurassic of England and Scotland. Discovery The first fossils of ''Palaeoxonodon ooliticus'' were found in the Kirtlington cement quarry, Oxfordshire, England. This site was rich in Mesozoic mammal remains from the Bathonian Forest Marble Formation. Later, two more species of ''Palaeoxonodon'' were named from the same site, ''P. leesi'' and ''P. freemani''.Sigogneau-Russell D. 2003. Holotherian mammals from the Forest Marble(Middle Jurassic of England). ''Geodiversitas'', 25, 501–537. All of these fossils were individual teeth. However, a recent fossil recovered from the Kilmaluag Formation of Skye, Scotland comprised a lower jaw with five molar teeth, four premolars, a Canine tooth, canine and one incisor present. This more complete fossil suggests that the separate species previously named from England were in fact all the same species, ''P. ooliticus'', and only appeared different due to their diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladotherian
Cladotheria is a clade (sometimes ranked as a legion) of mammals. It contains modern therian mammals (marsupials and placentals) and several extinct groups, such as the dryolestoids, amphitheriids and peramurids. The clade was named in 1975 by Malcolm McKenna. In 2002, it was defined as a node-based taxon containing "the common ancestor of dryolestids and living therians, plus all its descendants". A different, stem-based definition was given in 2013, in which Cladotheria contains all taxa that are closer to ''Mus musculus'' (the house mouse) than to the " symmetrodont" ''Spalacotherium tricuspidens''. Description Early cladotherians can be distinguished from other mammals by a number of derived traits (apomorphies). Their teeth differed from those of the " symmetrodonts" by the evolution of a talonid shelf ( hypoflexid) on the lower molars, which occluded with the paracone of the corresponding upper molars. A true talonid basin, allowing for the crushing and grinding of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Marble Formation
The Forest Marble is a geological formation in England. Part of the Great Oolite Group, it dates to the late Bathonian stage of the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 538–541. . Lithology The primary lithology of the formation typically consists of greenish grey variably calcareous silicate mudstone, with lenticular cross bedded limestone units deposited in a marine setting. Dinosaurian fauna Ornithischians Saurischians Microvertebrate fauna Despite the formation being nearly entirely marine, at several localities abundant remains of terrestrial microvertebrates are found, the primary locality being the Kirtlington Mammal Bed (designated 3p) in Kirtlington Quarry near Kirtlington, Oxfordshire. Another important locality is Watton Cliff near Eype in Dorset. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megalosaurus
''Megalosaurus'' (meaning "great lizard", from Greek , ', meaning 'big', 'tall' or 'great' and , ', meaning 'lizard') is an extinct genus of large carnivorous theropod dinosaurs of the Middle Jurassic period (Bathonian stage, 166 million years ago) of Southern England. Although fossils from other areas have been assigned to the genus, the only certain remains of ''Megalosaurus'' come from Oxfordshire and date to the late Middle Jurassic. ''Megalosaurus'' was, in 1824, the first genus of non-avian dinosaur to be validly named. The type species is ''Megalosaurus bucklandii'', named in 1827. In 1842, ''Megalosaurus'' was one of three genera on which Richard Owen based his Dinosauria. On Owen's directions a model was made as one of the Crystal Palace Dinosaurs, which greatly increased the public interest for prehistoric reptiles. Over fifty other species would eventually be classified under the genus; at first, this was because so few types of dinosaur had been identified, but the ... [...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 subd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Robert Joseph Gay Savage (2 July 1927 – 9 May 1998) was a British palaeontologist known as Britain's leading expert on fossil mammals. He worked at the University of Bristol for nearly 40 years and studied fossils around the world, especially ... and Michael Waldman.Waldman, M and Savage, R.J.G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsupial
Marsupials are any members of the mammalian infraclass Marsupialia. All extant marsupials are endemic to Australasia, Wallacea and the Americas. A distinctive characteristic common to most of these species is that the young are carried in a pouch. Marsupials include opossums, Tasmanian devils, kangaroos, koalas, wombats, wallabies, bandicoots, and the extinct thylacine. Marsupials represent the clade originating from the last common ancestor of extant metatherians, the group containing all mammals more closely related to marsupials than to placentals. They give birth to relatively undeveloped young that often reside in a pouch located on their mothers' abdomen for a certain amount of time. Close to 70% of the 334 extant species occur on the Australian continent (the mainland, Tasmania, New Guinea and nearby islands). The remaining 30% are found in the Americas—primarily in South America, thirteen in Central America, and one species, the Virginia opossum, in Nort ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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