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Polycotylus Latipinnis
''Polycotylus'' is a genus of plesiosaur within the family Polycotylidae. The type species is ''P. latippinis'' and was named by American paleontologist Edward Drinker Cope in 1869. Eleven other species have been identified. The name means 'much-cupped vertebrae', referring to the shape of the vertebrae. It lived in the Western Interior Seaway of North America toward the end of the Cretaceous. One fossil preserves an adult with a single large fetus inside of it, indicating that ''Polycotylus'' gave live birth, an unusual adaptation among reptiles. History Edward Drinker Cope named ''Polycotylus'' from the Niobrara Formation in Kansas in 1869. The holotype bones from which he based his description were fragmentary, representing only a small portion of the skeleton. A more complete skeleton was later found in Kansas and was described in 1906. A nearly complete skeleton was found in 1949 from the Mooreville Chalk Formation in Alabama, but was not described until 2002. A new specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Drinker Cope
Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of 19. Though his father tried to raise Cope as a gentleman farmer, he eventually acquiesced to his son's scientific aspirations. Cope married his cousin and had one child; the family moved from Philadelphia to Haddonfield, New Jersey, although Cope would maintain a residence and museum in Philadelphia in his later years. Cope had little formal scientific training, and he eschewed a teaching position for field work. He made regular trips to the American West, prospecting in the 1870s and 1880s, often as a member of United States Geological Survey teams. A personal feud between Cope and paleontologist Othniel Charles Marsh led to a period of intense fossil-finding competition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ischium
The ischium () forms the lower and back region of the (''os coxae''). Situated below the ilium and behind the pubis, it is one of three regions whose fusion creates the . The superior portion of this region forms approximately one-third of the acetabulum. |
Polycotylus Latipinnis Paddle Williston
''Polycotylus'' is a genus of plesiosaur within the family (biology), family Polycotylidae. The type species is ''P. latippinis'' and was named by American paleontologist Edward Drinker Cope in 1869. Eleven other species have been identified. The name means 'much-cupped vertebrae', referring to the shape of the vertebrae. It lived in the Western Interior Seaway of North America toward the end of the Late Cretaceous, Cretaceous. One fossil preserves an adult with a single large fetus inside of it, indicating that ''Polycotylus'' gave live birth, an unusual adaptation among reptiles. History Edward Drinker Cope named ''Polycotylus'' from the Niobrara Formation in Kansas in 1869. The holotype bones from which he based his description were fragmentary, representing only a small portion of the skeleton. A more complete skeleton was later found in Kansas and was described in 1906. A nearly complete skeleton was found in 1949 from the Mooreville Chalk Formation in Alabama, but was not d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptocleidus
''Cryptoclidus'' ( ) is a genus of plesiosaur reptile from the Middle Jurassic period of England, France, and Cuba. Discovery ''Cryptoclidus'' was a plesiosaur whose specimens include adult and juvenile skeletons, and remains which have been found in various degrees of preservation in England, Northern France, Russia, and South America. Its name, meaning "hidden clavicles", refer to its small, practically invisible clavicles buried in its front limb girdle. The type species was initially described as '' Plesiosaurus eurymerus'' by Phillips (1871). The specific name "wide femur" refers to the forelimb, which was mistaken for a hindlimb at the time. Fossils of ''Cryptoclidus'' have been found in the Oxford Clay of Cambridgeshire, England. The dubious species ''Cryptoclidus beaugrandi'' is known from Kimmeridgian-age deposits in Boulogne-sur-Mer, France. ''Cryptoclidus vignalensis'', which is now considered undiagnostic, hails from the Jagua Formation of western Cuba. Descri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), 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, 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, 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 Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptocleidoidea
Cryptoclidia is a clade of plesiosaurs. Cryptoclidia was named and defined as a node clade in 2010 by Hilary Ketchum and Roger Benson: the group consisting of the last common ancestor of ''Cryptoclidus eurymerus'' and ''Polycotylus latipinnis''; and all its descendants. The following 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 d ... follows an analysis by Benson & Druckenmiller (2014). References Plesiosaurs {{plesiosaur-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peloneustes
''Peloneustes'' (meaning "mud swimmer") is a genus of pliosaurid plesiosaur from the Middle Jurassic of England. Its remains are known from the Peterborough Member of the Oxford Clay Formation, which is Callovian in age. It was originally described as a species of ''Plesiosaurus'' by palaeontologist Harry Govier Seeley in 1896, before being given its own genus by naturalist Richard Lydekker in 1889. While many species have been assigned to ''Peloneustes'', ''P. philarchus'' is currently the only one still considered valid, with the others moved to different genera, considered '' nomina dubia'', or synonymised with ''P. philarchus''. Some of the material formerly assigned to ''P. evansi'' have since been reassigned to ''"Pliosaurus" andrewsi''. ''Peloneustes'' is known from many specimens, including some very complete material. With a total length of , ''Peloneustes'' is not a large pliosaurid. It had a large, triangular skull, which occupied about a fifth of its body length. The ... [...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] |
Pliosaur
Pliosauroidea is an extinct clade of plesiosaurs, known from the earliest Jurassic to early Late Cretaceous. They are best known for the subclade Thalassophonea, which contained crocodile-like short-necked forms with large heads and massive toothed jaws, commonly known as pliosaurs. More primitive non-thalassophonean pliosauroids resembled pleisiosaurs in possessing relatively long necks and smaller heads. They originally included only members of the family Pliosauridae, of the order Plesiosauria, but several other genera and families are now also included, the number and details of which vary according to the classification used. The distinguishing characteristics are a short neck and an elongated head, with larger hind flippers compared to the fore flippers, the opposite of the plesiosaurs. They were carnivorous and their long and powerful jaws carried many sharp, conical teeth. Pliosaurs range from 4 to 15 metres and more in length. Their prey may have included fish, sharks, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elasmosaurus
''Elasmosaurus'' (;) is a genus of plesiosaur that lived in North America during the Campanian stage of the Late Cretaceous period, about 80.5million years ago. The first specimen was discovered in 1867 near Fort Wallace, Kansas, US, and was sent to the American paleontologist Edward Drinker Cope, who named it ''E.platyurus'' in 1868. The generic name means "thin-plate reptile", and the specific name means "flat-tailed". Cope originally reconstructed the skeleton of ''Elasmosaurus'' with the skull at the end of the tail, an error which was made light of by the paleontologist Othniel Charles Marsh, and became part of their "Bone Wars" rivalry. Only one incomplete ''Elasmosaurus'' skeleton is definitely known, consisting of a fragmentary skull, the spine, and the pectoral and pelvic girdles, and a single species is recognized today; other species are now considered invalid or have been moved to other genera. Measuring in length and in body mass, ''Elasmosaurus'' would have ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
