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Florissantia (planthopper)
''Florissantia'' is an extinct monotypic genus of planthopper in the dictyopharid subfamily Dictyopharinae. The single species, ''Florissantia elegans,'' was described by Samuel Hubbard Scudder (1890) from fossils found in the Florissant Formation of Colorado. History and classification At the time of description, both the holotype and paratype of ''F. elegans'' were deposited in the paleoentomology collections at Princeton University, with Samuel Scudder's type description of the genus and species being published in a ''United States Geological Survey of the Territories'' 1890 monograph. Scudder named the monotypic genus ''Florissantia'' after the type locality of Florissant, but did not elaborate on the etymology of the species name ''elegans''. At the time of description Scudder placed the genus into "subfamily Cixiida" of the "family Fulgorina". The family was later elevated to Superfamily treatment as Fulgoroidea encompassing all planthoppers, with subfamily "Cix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cixiidae
The Cixiidae are a family of fulgoroid insects, one of many families commonly known as planthoppers, distributed worldwide and comprising more than 2,000 species from over 150 genera. The genera are placed into three subfamilies, Borystheninae, Bothriocerinae and Cixiinae with sixteen tribes currently accepted in Cixiinae. Description Cixiid species are typically comparatively small (body size less than a centimeter) and usually inconspicuous. The face is longer than wide and the head is narrower than the pronotum. The forewings are at least partly transparent and the veins bear minute setae. The hind tibiae end in a cluster of spines and may sometimes have spines along their length. Nymphs live underground, feeding on roots. Adults feed on herbs, shrubs and/or trees; some are polyphagous, while others are specialised on their host plants (monophagous). A couple of species are cavernicolous, feeding on roots in volcanic caves. Females occasionally bear impressive "wax tails ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod Leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: ''coxa'' (meaning hip, plural ''coxae''), ''trochanter'', ''femur'' (plural ''femora''), ''tibia'' (plural ''tibiae''), ''tarsus'' (plural ''tarsi''), ''ischium'' (plural ''ischia''), ''metatarsus'', ''carpus'', ''dactylus'' (meaning finger), ''patella'' (plural ''patellae''). Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for the most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a ''Hox''-gene, could result in parallel gains of leg segments. In arthropods, each of the leg segments ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterostigma
The pterostigma (plural: pterostigmata) is a group of specialized cells in the outer insect wing, wings of insects, which are often thickened or coloured, and thus stand out from other cells. It is particularly noticeable in dragonfly, dragonflies, but present also in other insect groups, such as snakefly, snakeflies, hymenopterans, and megalopterans. Purpose The pterostigma, a heavier section of the wing than nearby sections, assists in gliding. Without the pterostigmata, self-exciting vibrations known as aeroelastic flutter, flutter would set in on the wing above a certain critical speed, making gliding impossible. Tests show that with the pterostigmata, the critical gliding speed is increased 10–25% on one species of dragonfly. Pseudopterostigma Some female damselfly, damselflies in the family Calopterygidae possess a ''pseudopterostigma''. This is similar in location on the wing to a true pterostigma but is crossed by veins and is only defined by its paler colour compared ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hemelytra
An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alternatively spelled as "hemielytra"), and in most species only the basal half is thickened while the apex is membranous, but when they are entirely thickened the condition is referred to as "coleopteroid". An elytron is sometimes also referred to as a shard. Description The elytra primarily serve as protective wing-cases for the hindwings underneath, which are used for flying. To fly, a beetle typically opens the elytra and then extends the hindwings, flying while still holding the elytra open, though many beetles in the families Scarabaeidae and Buprestidae can fly with the elytra closed (e.g., most Cetoniinae; ). In a number of groups, the elytra are reduced to various degrees, (e.g., the beetle families Staphylinidae and Ripiphoridae), or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleothermometer
A paleothermometer is a methodology that provides an estimate of the ambient temperature at the time of formation of a natural material. Most paleothermometers are based on empirically-calibrated proxy relationships, such as the tree ring or TEX86 methods. Isotope methods, such as the δ18O method or the clumped-isotope method, are able to provide, at least in theory, direct measurements of temperature. Common paleothermometers The isotopic ratio of 18O to 16O, usually in foram tests or ice cores. High values mean low temperatures. Confounded by ice volume - more ice means higher values. Ocean water is mostly H216O, with small amounts of HD16O and H218O. In Standard Mean Ocean Water (SMOW) the ratio of D to H is and 18O/16O is . Fractionation occurs during changes between condensed and vapour phases: the vapour pressure of heavier isotopes is lower, so vapour contains relatively more of the lighter isotopes and when the vapour condenses the precipitation preferentia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate
Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation. In a broader sense, climate is the state of the components of the climate system, including the atmosphere, hydrosphere, cryosphere, lithosphere and biosphere and the interactions between them. The climate of a location is affected by its latitude/longitude, terrain, altitude, land use and nearby water bodies and their currents. Climates can be classified according to the average and typical variables, most commonly temperature and precipitation. The most widely used classification scheme was the Köppen climate classification. The Thornthwaite system, in use since 1948, incorporates evapotranspiration along with temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elevation
The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Vertical datum). The term ''elevation'' is mainly used when referring to points on the Earth's surface, while ''altitude'' or ''geopotential height'' is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, and '' depth'' is used for points below the surface. Elevation is not to be confused with the distance from the center of the Earth. Due to the equatorial bulge, the summits of Mount Everest and Chimborazo have, respectively, the largest elevation and the largest geocentric distance. Aviation In aviation the term elevation or aerodrome elevation is defined by the ICAO as the highest point of the landing area. It is often measured in feet and can be found in approach charts of the aerodrome. It is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biota (plant)
''Platycladus'' is a monotypic genus of evergreen coniferous trees in the cypress family Cupressaceae, containing only one species, ''Platycladus orientalis'', also known as Chinese thuja, Oriental arborvitae, Chinese arborvitae, biota or Oriental thuja. It is native to northeastern parts of East Asia and North Asia, but is also now naturalised as an introduced species in other regions of the Asian continent. Description A monoecious tree, it is small, slow-growing, reaching and trunk diameter (exceptionally to tall and diameter in very old trees). The foliage forms in flat sprays with scale-like leaves long, which are bright green in colour but may turn brownish or coppery orange in winter. The cones are long, green ripening brown in about eight months from pollination, and have 6–12 thick scales arranged in opposite pairs. The seeds are long, with no wing. The branches are relatively short, loosely arranged and, usually, sharply directed upwards, and the bark, browni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biogeographic
Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, isolation and habitat area.Brown University, "Biogeography." Accessed February 24, 2014. . Phytogeography is the branch of biogeography that studies the distribution of plants. Zoogeography is the branch that studies distribution of animals. Mycogeography is the branch that studies distribution of fungi, such as mushrooms. Knowledge of spatial variation in the numbers and types of organisms is as vital to us today as it was to our early human ancestors, as we adapt to heterogeneous but geographically predictable environments. Biogeography is an integrative field of inquiry that unites concepts and information from ecology, evolutionary biology, taxonomy, geology, physical geography, palaeontology, and climatology.Dansereau, Pierre. 195 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanidine
Sanidine is the high temperature form of potassium feldspar with a general formula K(AlSi3O8). Sanidine is found most typically in felsic volcanic rocks such as obsidian, rhyolite and trachyte. Sanidine crystallizes in the monoclinic crystal system. Orthoclase is a monoclinic polymorph stable at lower temperatures. At yet lower temperatures, microcline, a triclinic polymorph of potassium feldspar, is stable. Due to the high temperature and rapid quenching, sanidine can contain more sodium in its structure than the two polymorphs that equilibrated at lower temperatures. Sanidine and high albite constitute a solid solution series with intermediate compositions termed anorthoclase. Exsolution of an albite phase does occur; resulting cryptoperthite can best be observed in electron microprobe images. Occurrence In addition to its presence in the groundmass of felsic rocks, sanidine is a common phenocryst in rhyolites and, to a lesser extent, rhyodacites. Trachyte consists largely of fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
