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Simolestes
''Simolestes'' (meaning "hearkening thief") is an extinct pliosaurid genus that lived in the Middle to Late Jurassic. The type specimen, BMNH R. 3319 is an almost complete but crushed skeleton diagnostic to ''Simolestes vorax'', dating back to the Callovian of the Oxford Clay formation, England. The genus is also known from the Callovian and Bajocian of France (''S.keileni''), and the Tithonian of India (''S.indicus''). The referral of these two species to ''Simolestes'' is dubious, however. Description ''Simolestes'' possessed a short, high, and wide skull which was built to resist torsional forces when hunting. The largest specimens of ''S.vorax'' reached approximately in length, if a head to body ratio similar to ''Liopleurodon'' is applied. ''S.keileni'' was larger, with specimens from France suggesting that some individuals grew more than long. ''S. vorax'' and ''S. keileni'' weighed about , respectively. Palaeobiology Like most Pliosaurs, ''Simolestes'' possessed sal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simolestes Size Chart
''Simolestes'' (meaning "hearkening thief") is an extinct pliosaurid genus that lived in the Middle to Late Jurassic. The type specimen, BMNH R. 3319 is an almost complete but crushed skeleton diagnostic to ''Simolestes vorax'', dating back to the Callovian of the Oxford Clay formation, England. The genus is also known from the Callovian and Bajocian of France (''S.keileni''), and the Tithonian of India (''S.indicus''). The referral of these two species to ''Simolestes'' is dubious, however. Description ''Simolestes'' possessed a short, high, and wide skull which was built to resist torsional forces when hunting. The largest specimens of ''S.vorax'' reached approximately in length, if a head to body ratio similar to ''Liopleurodon'' is applied. ''S.keileni'' was larger, with specimens from France suggesting that some individuals grew more than long. ''S. vorax'' and ''S. keileni'' weighed about , respectively. Palaeobiology Like most Pliosaurs, ''Simolestes'' possessed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simolestes Skull Side1
''Simolestes'' (meaning "hearkening thief") is an extinct pliosaurid genus that lived in the Middle to Late Jurassic. The type specimen, BMNH R. 3319 is an almost complete but crushed skeleton diagnostic to ''Simolestes vorax'', dating back to the Callovian of the Oxford Clay formation, England. The genus is also known from the Callovian and Bajocian of France (''S.keileni''), and the Tithonian of India (''S.indicus''). The referral of these two species to ''Simolestes'' is dubious, however. Description ''Simolestes'' possessed a short, high, and wide skull which was built to resist torsional forces when hunting. The largest specimens of ''S.vorax'' reached approximately in length, if a head to body ratio similar to ''Liopleurodon'' is applied. ''S.keileni'' was larger, with specimens from France suggesting that some individuals grew more than long. ''S. vorax'' and ''S. keileni'' weighed about , respectively. Palaeobiology Like most Pliosaurs, ''Simolestes'' possessed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiosaur
The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period, possibly in the Rhaetian stage, about 203 million years ago. They became especially common during the Jurassic Period, thriving until their disappearance due to the Cretaceous–Paleogene extinction event at the end of the Cretaceous Period, about 66 million years ago. They had a worldwide oceanic distribution, and some species at least partly inhabited freshwater environments. Plesiosaurs were among the first fossil reptiles discovered. In the beginning of the nineteenth century, scientists realised how distinctive their build was and they were named as a separate order in 1835. The first plesiosaurian genus, the eponymous ''Plesiosaurus'', was named in 1821. Since then, more than a hundred valid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford Clay
The Oxford Clay (or Oxford Clay Formation) is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay Formation dates to the Jurassic, specifically, the Callovian and Oxfordian ages, and comprises two main facies. The lower facies comprises the Peterborough Member, a fossiliferous organic-rich mudstone. This facies and its rocks are commonly known as lower Oxford Clay. The upper facies comprises the middle Oxford Clay, the Stewartby Member, and the upper Oxford Clay, the Weymouth Member. The upper facies is a fossil poor assemblage of calcareous mudstones. Oxford Clay appears at the surface around Oxford, Peterborough and Weymouth and is exposed in many quarries around these areas. The top of the Lower Oxford Clay shows a lithological change, where fissile shale changes to grey mudstone. The Middle and Upper Oxford Clays differ slightly, as they are separated by an argillaceou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liopleurodon
''Liopleurodon'' (; meaning 'smooth-sided teeth') is an extinct genus of large, carnivorous marine reptile belonging to the Thalassophonea, a clade of short-necked pliosaurid plesiosaurs. ''Liopleurodon'' lived from the Callovian Stage of the Middle Jurassic to the Kimmeridgian stage of the Late Jurassic Period (c. 166 to 155 mya). It was the apex predator of the Middle to Late Jurassic seas that covered Europe. The largest species, ''L. ferox'', is estimated to have grown up to in length, but could have been larger. The name "Liopleurodon" (meaning "smooth-sided tooth") derives from Ancient Greek words: ', "smooth"; ', "side" or "rib"; and ', "tooth". Discovery and species Even before ''Liopleurodon'' was named, material likely belonging to it was described. In 1841, Hermann von Meyer named the species ''Thaumatosaurus oolithicus'' based on a fragmentary specimen consisting of partial teeth, skull elements, vertebrae, and ribs from deposits in Württemberg, Germany poss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachycostasaurus
''Pachycostasaurus'' (meaning 'thick-ribbed lizard') is an extinct Pliosauroid from the Oxford Clay formation of Peterborough, England. History and naming The holotype fossil of Pachycostasaurus was discovered by Alan Dawn, an amateur geologist and museum volunteer, in what is now a quarry in Peterborough. The fossil was described in 1997 by Palaeontologists Arthur Cruickshank, David Martill and Leslie Noè, due to its distinct set of features not present in contemporary pliosaurids ''Liopleurodon'' and '' Simolestes.'' Description The type species, ''P. dawni'', is represented by a single near complete specimen (PETMG R338) which was approximately long and weighed . Perhaps the most defining feature of this genus is the large, pachyostic ribs and gastralia described as ‘sausage-like’ in profile. Pachyostosis is known from a number of Pliosaurid genera (for example ''Monquirasaurus''), and is present in modern animals such as Sirenians (Dugong and Manatees). This robust, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eurysaurus
''Eurysaurus'' (meaning "wide lizard") is an extinct genus of plesiosaur, originally classed as a nothosaur, from the Early Jurassic of Echenoz-la-Meline, France, named in 1878. The type material, consisting of a cranium, teeth and five vertebrae, is now lost.Gaudry, a. 1878. Sur un grand reptile fossil (the ''Eurysaurus raincourti''). Comptes rendus hebdomadaires des Séances de l ' Académie des Sciences, Paris, 86: 1031–1033. The type species is ''E. raincourti'', and a second species, ''E. schafferi'', was named in 1924 but it has since been absorbed into the unrelated genus ''Germanosaurus''.O. Rieppel. 1997. Revision of the sauropterygian reptile genus ''Cymatosaurus'' v. Fritsch, 1894, and the relationships of ''Germanosaurus'' Nopcsa, 1928, from the Middle Triassic of Europe. ''Fieldiana: Geology, new series'' History The holotype, first described in 1878 by Albert Gaudry, has since been lost. A new study based essentially on illustrations of the type material by Noà ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliosaurid
Pliosauridae is a family of plesiosaurian marine reptiles from the Latest Triassic to the early Late Cretaceous ( Rhaetian to Turonian stages) of Australia, Europe, North America and South America. The family is more inclusive than the archetypal short-necked large headed species that are placed in the subclade Thalassophonea, with basal forms resembling other plesiosaurs with long necks. They became extinct during the early Late Cretaceous and were subsequently replaced by the mosasaurs. It was formally named by Harry G. Seeley in 1874. Relationships Pliosauridae is a stem-based taxon defined in 2010 (and in earlier studies in a similar manner) as "all taxa more closely related to ''Pliosaurus brachydeirus'' than to '' Leptocleidus superstes'', '' Polycotylus latipinnis'' or ''Meyerasaurus victor''". The family Brachauchenidae has been proposed to include pliosauroids which have very short necks and may include ''Brachauchenius'' and ''Kronosaurus''. However, modern cladisti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonites
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) than they are to shelled nautiloids such as the living ''Nautilus'' species. The earliest ammonites appeared during the Devonian, with the last species vanishing during the Cretaceous–Paleogene extinction event. Ammonites are excellent index fossils, and linking the rock layer in which a particular species or genus is found to specific geologic time periods is often possible. Their fossil shells usually take the form of planispirals, although some helically spiraled and nonspiraled forms (known as heteromorphs) have been found. The name "ammonite", from which the scientific term is derived, was inspired by the spiral shape of their fossilized shells, which somewhat resemble tightly coiled rams' horns. Pliny the Elder ( 79 AD near Pomp ... [...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] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
