|
Biofact (archaeology)
In archaeology, a biofact (more commonly known as an ecofact) is any organic material including flora or fauna material found at an archaeological site that has not been technologically altered by humans yet still has cultural relevance. Biofacts/ecofacts can include but are not limited to plants, seeds, pollen, animal bones, insects, fish bones and mollusks. The study of biofacts/ecofacts, alongside other archaeological remains such as artifacts are a key element to understanding how past societies interacted with their surrounding environment and with each other. Biofacts/ecofacts also play a role in helping archaeologists understand questions of subsistence and reveals information about the domestication of certain plant species and animals which demonstrates, for example, the transition from a hunter-gatherer society to a farming society. Biofacts/ecofacts are differentiated from artifacts in that artifacts are typically considered anything purposefully manipulated or made by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biofact (biology)
In biology, a biofact is dead material of a once-living organism. In 1943, the protozoologist Bruno M. Klein of Vienna (1891–1968) coined the term in his article ''Biofakt und Artefakt'' in the microscopy journal ''Mikrokosmos'', though at that time it was not adopted by the scientific community. Klein's concept of biofact stressed the dead materials produced by living organisms as sheaths, such as shells. The word ''biofact'' is now widely used in the zoo/aquarium world, but was first used by Lisbeth Bornhofft in 1993 in the Education Department at the New England Aquarium, Boston, to refer to preserved items such as animal bones, skins, molts and eggs. The Accreditation Standards and Related Policies of the Association of Zoos and Aquariums states that biofacts can be useful education tools, and are preferable to live animals because of potential ethical considerations. See also *Biofact (archaeology) In archaeology, a biofact (more commonly known as an ecofact) is any o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ediacaran
The Ediacaran Period ( ) is a geological period that spans 96 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 538.8 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia. The Ediacaran Period's status as an official geological period was ratified in 2004 by the International Union of Geological Sciences (IUGS), making it the first new geological period declared in 120 years. Although the period takes its name from the Ediacara Hills where geologist Reg Sprigg first discovered fossils of the eponymous Ediacaran biota in 1946, the type section is located in the bed of the Enorama Creek within Brachina Gorge in the Flinders Ranges of South Australia, at . The Ediacaran marks the first appearance of widespread multicellular fauna following the end of Snowball Earth glaciation events, the so-called Ediacaran biota, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronacollina Acula
''Coronacollina acula'' is a multicellular organism from the Ediacaran period resembling the Cambrian 'sponge' ''Choia''. The organism comprised a raised, tri-radially-symmetrical central mound with a central depression and resistant spicules (up to four in articulated fossils), which were resistant — either chitin Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...ous or biomineralized — and grew to be 37 cm long. References External links * * Ediacaran life Enigmatic animal taxa Prehistoric invertebrates of Australia Fossil taxa described in 2012 {{Precambrian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaefructus
''Archaefructus'' is an extinct genus of herbaceous aquatic seed plants with three known species. Fossil material assigned to this genus originates from the Yixian Formation in northeastern China, originally dated as late Jurassic but now thought to be approximately 125 million years old, or early Cretaceous in age. Even with its revised age, ''Archaefructus'' has been proposed to be one of the earliest known genera of flowering plants. Because of its age, lack of sepals and petals, and the fact that its reproductive organs (carpels and stamens), are produced on an elongate stem rather than condensed into a flower as in modern angiosperms, Archaefructaceae has been proposed as a new basal angiosperm family. An alternative interpretation of the same fossil, however, interprets the elongate stem as an inflorescence rather than a flower, with staminate (male) flowers below and pistillate (female) flower above. The discovery of ''Archaefructus eoflora''Ji, Q., H. Li, L.M. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nymphaeaceae
Nymphaeaceae () is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world. The family contains nine genera with about 70 known species. Water lilies are rooted in soil in bodies of water, with leaves and flowers floating on or emergent from the surface. Leaves are round, with a radial notch in '' Nymphaea'' and ''Nuphar'', but fully circular in ''Victoria'' and ''Euryale''. Water lilies are a well-studied clade of plants because their large flowers with multiple unspecialized parts were initially considered to represent the floral pattern of the earliest flowering plants, and later genetic studies confirmed their evolutionary position as basal angiosperms. Analyses of floral morphology and molecular characteristics and comparisons with a sister taxon, the family Cabombaceae, indicate, however, that the flowers of extant water lilies with the most floral parts are more derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archaefructus Liaoningensis
''Archaefructus'' is an extinct genus of herbaceous aquatic seed plants with three known species. Fossil material assigned to this genus originates from the Yixian Formation in northeastern China, originally dated as late Jurassic but now thought to be approximately 125 million years old, or early Cretaceous in age. Even with its revised age, ''Archaefructus'' has been proposed to be one of the earliest known genera of flowering plants. Because of its age, lack of sepals and petals, and the fact that its reproductive organs (carpels and stamens), are produced on an elongate stem rather than condensed into a flower as in modern angiosperms, Archaefructaceae has been proposed as a new basal angiosperm family. An alternative interpretation of the same fossil, however, interprets the elongate stem as an inflorescence rather than a flower, with staminate (male) flowers below and pistillate (female) flower above. The discovery of ''Archaefructus eoflora''Ji, Q., H. Li, L.M. Bowe, Y. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratified Sampling
In statistics, stratified sampling is a method of sampling from a population which can be partitioned into subpopulations. In statistical surveys, when subpopulations within an overall population vary, it could be advantageous to sample each subpopulation (stratum) independently. Stratification is the process of dividing members of the population into homogeneous subgroups before sampling. The strata should define a partition of the population. That is, it should be ''collectively exhaustive'' and ''mutually exclusive'': every element in the population must be assigned to one and only one stratum. Then simple random sampling is applied within each stratum. The objective is to improve the precision of the sample by reducing sampling error. It can produce a weighted mean that has less variability than the arithmetic mean of a simple random sample of the population. In computational statistics, stratified sampling is a method of variance reduction when Monte Carlo methods are us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrat
A quadrat is a frame, traditionally square, used in ecology, geography and biology to isolate a standard unit of area for study of the distribution of an item over a large area. Modern quadrats can for example be rectangular, circular, or irregular. The quadrat is suitable for sampling plants, slow-moving animals, and some aquatic organisms. A photo-quadrat is a photographic record of the area framed by a quadrat. It may use a physical frame to indicate the area, or may rely on fixed camera distance and lens field of view to automatically cover the specified area of substrate. Parallel laser pointers mounted on the camera can also be used as scale indicators. The photo is taken perpendicular to the surface, or as close as possible to perpendicular for uneven surfaces. History The systematic use of quadrats was developed by the pioneering plant ecologists R. Pound and F. E. Clements between 1898 and 1900. The method was then swiftly applied for many purposes in ecology, such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterlogging (archaeology)
In archaeology, waterlogging refers to the long-term exclusion of air by groundwater, which creates an anaerobic environment that can preserve artifacts perfectly. Such waterlogging preserves perishable artifacts. Thus, in a site which has been waterlogged since the archaeological horizon was deposited, exceptional insight may be obtained by study of artifacts made of leather, wood, textile or similar materials. 75-90% of the archaeological remains at wetland sites are found to be organic material. Tree rings found from logs that have been preserved allow archaeologists to accurately date sites. Wetland sites include all those found in lakes, swamps, marshes, fens, and peat bogs. Peat bogs, nearly all of which occur in northern latitudes, are some of the most important environments for wetland archaeology. Peat bogs have likewise preserved many wooden trackways, including the world's oldest road, which is a 6,000-year-old one-mile stretch of track. Bog bodies are the best-known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
