|
Menarana
''Menarana'' is an extinct genus of madtsoiid snake which existed in Madagascar during the Late Cretaceous. The type species is ''Menarana nosymena''. Several vertebrae and rib fragments as well as part of the basicranium have been found from the Maastrichtian-age Maevarano Formation in the Mahajanga Basin. Paleobiology ''Menarana'' was around long and was probably fossorial, burrowing with its head. Evidence of a fossorial lifestyle can be found in its braincase, as the bones of the basicranium are highly fused to withstand stresses from burrowing. This degree of fusion is otherwise only seen in caecilians, amphisbaenians, and uropeltid snakes, all of which are highly specialized burrowers. The vertebrae are depressed and have very low neural spines similar to those of living burrowing snakes. The atlas, which is the first vertebra of the spine closest to the head, may show adaptations toward structural integrity under loads that would be encountered during tunnel excavation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madtsoiidae
Madtsoiidae is an extinct family of mostly Gondwanan snakes with a fossil record extending from early Cenomanian (Upper Cretaceous) to late Pleistocene strata located in South America, Africa, India, Australia and Southern Europe. Madtsoiidae include very primitive snakes, which like extant boas and pythons would likely dispatch their prey by constriction. Genera include '' Madtsoia'', one of the longest snakes known, at an estimated , and the Australian '' Wonambi'' and '' Yurlunggur''. As a grouping of basal forms the composition and even the validity of Madtsoiidae is in a state of flux as new pertinent finds are described, with more recent evidence suggesting that it is paraphyletic as previously defined. Although madtsoiids persisted on Australia until the Pleistocene, they largely went extinct elsewhere during the Eocene. However, some species persisted in South America and India through the Oligocene. Description Madtsoiidae was first classified as a subfamily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2010 In Paleontology
Plants Angiosperms Molluscs Newly named bivalves Arthropods Fishes Amphibians Newly named amphibians Basal reptiles Newly named basal reptiles Ichthyopterygians Newly named ichthyopterygians Lepidosauromorphs Newly named plesiosaurs Newly named basal lepidosaurs Newly named lizards Newly named snakes Turtles Newly named turtles Archosauromorphs Newly named basal archosauromorphs Archosaurs Synapsids Newly named non-mammalian synapsids Mammals Other animals Footnotes Complete author list As science becomes more collaborative, papers with large numbers of authors are becoming more common. To prevent the deformation of the tables, these footnotes list the contributors to papers that erect new genera and have many authors. References {{Reflist, 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maevarano Formation
The Maevarano Formation is a Late Cretaceous sedimentary rock formation found in the Mahajanga Province of northwestern Madagascar. It is most likely Maastrichtian in age, and records a seasonal, semiarid environment with rivers that had greatly varying discharges. Notable animal fossils recovered include the theropod dinosaur ''Majungasaurus'', the early bird ''Vorona'', the paravian ''Rahonavis'', the titanosaurian sauropod ''Rapetosaurus'', and the giant frog ''Beelzebufo''. Description The Maevarano Formation is well exposed in the Mahajanga Basin, in particular near the village of Berivotra near the northwestern coast of the island where its outcrops have been heavily dissected by erosion. At the time it was being deposited, its latitude was between 30°S and 25°S as Madagascar drifted northward after splitting from India about 88 million years ago. It is composed of three smaller units or members. The lowest is the Masorobe Member, which is usually reddish and is at least ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadratic Function
In mathematics, a quadratic polynomial is a polynomial of degree two in one or more variables. A quadratic function is the polynomial function defined by a quadratic polynomial. Before 20th century, the distinction was unclear between a polynomial and its associated polynomial function; so "quadratic polynomial" and "quadratic function" were almost synonymous. This is still the case in many elementary courses, where both terms are often abbreviated as "quadratic". For example, a univariate (single-variable) quadratic function has the form :f(x)=ax^2+bx+c,\quad a \ne 0, where is its variable. The graph of a function, graph of a univariate quadratic function is a parabola, a curve that has an axis of symmetry parallel to the -axis. If a quadratic function is equation, equated with zero, then the result is a quadratic equation. The solutions of a quadratic equation are the zero of a function, zeros of the corresponding quadratic function. The bivariate function, bivariate case ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atlas (anatomy)
In anatomy, the atlas (C1) is the most superior (first) cervical vertebra of the spine and is located in the neck. It is named for Atlas of Greek mythology because, just as Atlas supported the globe, it supports the entire head. The atlas is the topmost vertebra and, with the axis (the vertebra below it), forms the joint connecting the skull and spine. The atlas and axis are specialized to allow a greater range of motion than normal vertebrae. They are responsible for the nodding and rotation movements of the head. The atlanto-occipital joint allows the head to nod up and down on the vertebral column. The dens acts as a pivot that allows the atlas and attached head to rotate on the axis, side to side. The atlas's chief peculiarity is that it has no body. It is ring-like and consists of an anterior and a posterior arch and two lateral masses. The atlas and axis are important neurologically because the brainstem extends down to the axis. Structure Anterior arch The anterio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Arch
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch (in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occipital Condyle
The occipital condyles are undersurface protuberances of the occipital bone in vertebrates, which function in articulation with the superior facets of the atlas vertebra. The condyles are oval or reniform (kidney-shaped) in shape, and their anterior extremities, directed forward and medialward, are closer together than their posterior, and encroach on the basilar portion of the bone; the posterior extremities extend back to the level of the middle of the foramen magnum. The articular surfaces of the condyles are convex from before backward and from side to side, and look downward and lateralward. To their margins are attached the capsules of the atlanto-occipital joints, and on the medial side of each is a rough impression or tubercle for the alar ligament. At the base of either condyle the bone is tunnelled by a short canal, the hypoglossal canal. Clinical significance Fracture of an occipital condyle may occur in isolation, or as part of a more extended basilar skull fracture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yurlunggur
''Yurlunggur'' is a genus of fossil snake in the extinct family Madtsoiidae. This genus was a part of the extinct megafauna of Australia, and contains the species ''Yurlunggur camfieldensis''. ''Y. camfieldensis'' was a large apex predator that typically reached in length, with one vertebra from the Wyandotte Creek suggesting a maximum length of . It persisted in the region from the Oligocene until the Miocene epoch. It is described as a member of the family Madtsoiidae, that includes the species such as ''Wonambi naracoortensis'', present in Australia until the Pleistocene. The name of the genus is derived from traditional name given by the people of Arnhem Land to the Rainbow serpent. They closely resemble '' Varanus'' (monitors) more than small burrowing lizards. John Scanlon has presented this as evidence of descent from the former, rather than burrowing ancestors that evolved into the elongate and legless snakes. The fossil material described by this species includes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species, are among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Spine
The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic irregular bone whose complex structure is composed primarily of bone, and secondarily of hyaline cartilage. They show variation in the proportion contributed by these two tissue types; such variations correlate on one hand with the cerebral/caudal rank (i.e., location within the backbone), and on the other with phylogenetic differences among the vertebrate taxa. The basic configuration of a vertebra varies, but the bone is its ''body'', with the central part of the body constituting the ''centrum''. The upper (closer to) and lower (further from), respectively, the cranium and its central nervous system surfaces of the vertebra body support attachment to the intervertebral discs. The posterior part of a vertebra forms a vertebral arch (in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notosuchia
Notosuchia is a suborder of primarily Gondwanan mesoeucrocodylian crocodylomorphs that lived during the Jurassic and Cretaceous. Some phylogenies recover Sebecosuchia as a clade within Notosuchia, others as a sister group (see below); if Sebecosuchia is included within Notosuchia its existence is pushed into the Middle Miocene, about 11 million years ago. Fossils have been found from South America, Africa, Asia, and Europe. Notosuchia was a clade of terrestrial crocodilians that evolved a range of feeding behaviours, including herbivory ('' Chimaerasuchus''), omnivory (''Simosuchus''), and terrestrial hypercarnivory (''Baurusuchus''). It included many members with highly derived traits unusual for crocodylomorphs, including mammal-like teeth, flexible bands of shield-like body armor similar to those of armadillos (''Armadillosuchus''), and possibly fleshy cheeks and pig-like snouts (''Notosuchus''). The suborder was first named in 1971 by Zulma Gasparini and has since undergone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
