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Paleodictyon P
''Paleodictyon'' is a trace fossil, usually interpreted to be a burrow, which appears in the geologic marine record beginning in the Precambrian/Early Cambrian and in modern ocean environments.Swinbanks, D. D., 1982: ''Paleodictyon'': the traces of infaunal xenophyophores? Science, v. 218, 47-49. ''Paleodictyon'' were first described by Giuseppe Meneghini in 1850. The origin of the trace fossil is enigmatic and numerous candidates have been proposed. Description ''Paleodictyon'' consist of thin tunnels or ridges that usually form hexagonal or polygonal-shaped honeycomb-like network.KU Ichnology - Studying the Traces of Life IBGS Research Group Both irregular and regular nets are known throughout the stratigraphic range of ''Paleodictyon'', but it is the striking regular honeycomb patte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giuseppe Giovanni Antonio Meneghini
Giuseppe Giovanni Antonio Meneghini (30 July 1811, Padua – 29 January 1889, Pisa) was an Italian botanist, geologist and paleontologist. Biography Meneghini became interested in science under his school teacher Pietro Melo. Following school he joined the medical course at the University of Padua in 1829-30 and obtained his medical doctorate in 1834 with a thesis on the cephalo-spinal axis and the following year, he became an assistant to Giuseppe Antonio Bonato, the chair of botany. In 1839 he was appointed professor of preparatory sciences at Padua, a position he maintained up until 1848, when he was removed from his post due to his association with revolutionaries during the First Italian War of Independence, in which he followed the leadership of his brother Andrea. He then went into exile to Bologna followed by Pistoia and then Florence. In 1849 he became a professor of mineralogy and geology at the University of Pisa, where the position had become vacant after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenophyophorea
Xenophyophorea is a clade of foraminiferans. Members of this class are multinucleate unicellular organisms found on the ocean floor throughout the world's oceans, at depths of . They are a kind of foraminiferan that extract minerals from their surroundings and use them to form an exoskeleton known as a test. They were first described by Henry Bowman Brady in 1883. They are abundant on abyssal plains, and in some regions are the dominant species. Fifteen genera and 75 species have been described, varying widely in size. The largest, ''Syringammina fragilissima'', is among the largest known coenocytes, reaching up to in diameter. Naming and classification The name Xenophyophora means "bearer of foreign bodies", from the Greek. This refers to the sediments, called xenophyae, which are cemented together to construct their tests. In 1883, Henry Bowman Brady classified them as primitive Foraminifera. Later they were placed within the sponges. In the beginning of the 20th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burrow Fossils
Burrow fossils are the remains of burrows - holes or tunnels excavated into the ground or seafloor - by animals to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion preserved in the rock record. Because burrow fossils represent the preserved byproducts of behavior rather than physical remains, they are considered a kind of trace fossil. One common kind of burrow fossil is known as Skolithos, and the similar Trypanites, Ophiomorpha and Diplocraterion. Vertebrate burrows Fish burrows Fossil Lungfish burrows are preserved in the Rocky Point Member of the Chinle Formation in Canyonlands National Park. Invertebrate burrows Examples are Treptichnus pedum ''Treptichnus'' (formerly named ''Phycodes'', ''Manykodes'' by J. Dzik, and also known as ''Trichophycus''See e.gfossiilid.info: paleodiversity in Baltoscandia: Trichophycus pedum/ref>) is the preserved burrow of an animal. As such, it is regar ... and Arenicolites franconicus. Footnotes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North American from the Eurasian Plate and the African Plate, north and south of the Azores Triple Junction respectively. In the South Atlantic, it separates the African and South American plates. The ridge extends from a junction with the Gakkel Ridge (Mid-Arctic Ridge) northeast of Greenland southward to the Bouvet Triple Junction in the South Atlantic. Although the Mid-Atlantic Ridge is mostly an underwater feature, portions of it have enough elevation to extend above sea level, for example in Iceland. The ridge has an average spreading rate of about per year. Discovery A ridge under the northern Atlantic Ocean was first inferred by Matthew Fontaine Maury in 1853, based on soundings by the USS ''Dolphin''. The existence of the ridge and its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DSV Alvin
''Alvin'' (DSV-2) is a crewed deep-ocean research submersible owned by the United States Navy and operated by the Woods Hole Oceanographic Institution (WHOI) in Woods Hole, Massachusetts. The vehicle was built by General Mills' Electronics Group in Minneapolis, Minnesota. Named to honor the prime mover and creative inspiration for the vehicle, Allyn Vine, ''Alvin'' was commissioned on 5 June 1964. The submersible is launched from the deep submergence support vessel , which is also owned by the U.S. Navy and operated by WHOI. The submersible has made more than 5,000 dives, carrying two scientists and a pilot, to observe the lifeforms that must cope with super-pressures and move about in total darkness, as well as exploring the wreck of ''Titanic''. Research conducted by ''Alvin'' has been featured in nearly 2,000 scientific papers. Design ''Alvin'' was designed as a replacement for bathyscaphes and other less maneuverable oceanographic vehicles. Its more nimble design was made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of The Deep Sea
''Volcanoes of the Deep Sea'' is a 2003 documentary film in the IMAX format about undersea volcanoes directed by Stephen Low. Production Richard Lutz served as Principal Investigator and Lutz and Peter A. Rona served as Science Directors of the film, which was funded by the National Science Foundation and co-produced by Rutgers University. Content The film included footage, research, and stories from the deep-sea ''Alvin'' expeditions of Lutz and his colleagues. Scientists use the deep-water submersible DSV Alvin to search for an organism, the Paleodictyon nodosum maker, that produces a honeycomb patterned fossil called a Paleodictyon, near volcanic vents that lie 3500 meters (12,000 feet) underwater in the Mid-Atlantic Ridge. Reception The film received the award for "best IMAX film of the Year" at the Paris Film Festival, and in 2005 Richard Lutz received the Scientific Literacy Achievement Award from the New Jersey Association for Biomedical Research for his contribution ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IMAX
IMAX is a proprietary system of high-resolution cameras, film formats, film projectors, and theaters known for having very large screens with a tall aspect ratio (approximately either 1.43:1 or 1.90:1) and steep stadium seating. Graeme Ferguson, Roman Kroitor, Robert Kerr, and William C. Shaw were the co-founders of what would be named the IMAX Corporation (founded in September 1967 as Multiscreen Corporation, Limited), and they developed the first IMAX cinema projection standards in the late 1960s and early 1970s in Canada. IMAX GT is the large format as originally conceived. It uses very large screens of and, unlike most conventional film projectors, the film runs horizontally so that the image width can be greater than the width of the film stock. It is called a 70/15 format. It is used exclusively in purpose-built theaters and dome theaters, and many installations limit themselves to a projection of high quality, short documentaries. The high costs involved in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexactinellid
Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma. Some experts believe glass sponges are thlongest-lived animals on earth these scientists tentatively estimate a maximum age of up to 15,000 years. Biology Glass sponges are relatively uncommon and are mostly found at depths from below the sea level. Although the species '' Oopsacas minuta'' has been found in shallow water, others have been found much deeper. They are found in all oceans of the world, although they are particularly common in Antarctic and Northern Pacific waters. They are more-or-less cup-shaped animals, ranging from in height, with sturdy lattice-like internal skeletons made up of fused spicules of silica. The body is relatively symmetrical, with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoplasm
Protoplasm (; ) is the living part of a cell that is surrounded by a plasma membrane. It is a mixture of small molecules such as ions, monosaccharides, amino acid, and macromolecules such as proteins, polysaccharides, lipids, etc. In some definitions, it is a general term for the cytoplasm (e.g., Mohl, 1846), but for others, it also includes the nucleoplasm (e.g., Strasburger, 1882). For Sharp (1921), "According to the older usage the extra-nuclear portion of the protoplast 'the entire cell, excluding the cell wall''was called "protoplasm," but the nucleus also is composed of protoplasm, or living substance in its broader sense. The current consensus is to avoid this ambiguity by employing Strasburger's '(1882)''terms cytoplasm Albert_von_Kölliker.html"_;"title="'coined_by_Albert_von_Kölliker">Kölliker_(1863),_originally_as_synonym_for_protoplasm''and_nucleoplasm_([''term_coined_by_Edouard_Van_Beneden.html" ;"title="Albert von Kölliker">Kölliker (1863), originally as syn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test (biology)
In biology, a test is the hard shell of some spherical marine animals and protists, notably sea urchins and microorganisms such as testate foraminiferans, radiolarians, and testate amoebae. The term is also applied to the covering of scale insects. The related Latin term testa is used for the hard seed coat of plant seeds. Etymology The anatomical term "test" derives from the Latin ''testa'' (which means a rounded bowl, amphora or bottle). Structure The test is a skeletal structure, made of hard material such as calcium carbonate, silica, chitin or composite materials. As such, it allows the protection of the internal organs and the attachment of soft flesh. In sea urchins The test of sea urchins is made of calcium carbonate, strengthened by a framework of calcite monocrystals, in a characteristic "stereomic" structure. These two ingredients provide sea urchins with a great solidity and a moderate weight, as well as the capacity to regenerate the mesh from the cuticle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stercomata
Stercomata (or stercomes) are extracellular pellets of waste material produced by some groups of foraminiferans, including xenophyophoreans and komokiaceans, ''Gromia'', and testate amoebae. The pellets are ovoid (egg-shaped), brownish in color, and on average measure from 10-20 µm in length. Stercomata are composed of small mineral grains and undigested waste products held together by strands of glycosaminoglycans. The term “sterkome” was first used Schaudinn in 1899 to describe the balls of undigested food remains produced by the testate amoeba ''Trichosphaerium sieboldi'', the foraminiferan ''Saccammina sphaerica'', and the gromiid ''Gromia dujardinii''. Schaudinn conducted feeding experiments on live individuals of ''Trichosphaerium sieboldi'' kept in culture dishes to confirm that stercomata were accumulations of waste material produced as a byproduct of feeding. Taxonomic distribution Foraminifera Stercomata are produced by members of several different subclades of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occultammina
''Occultammina'' is a genus of xenophyophorean foraminifera known from the Atlantic and Pacific oceans. It is notable for being the first known infaunal xenophyophore as well as for being a possible identity for the enigmatic trace fossil ''Paleodictyon''. Distribution and habitat Like all other known xenophyophores, ''Occultammina'' is found in the deep ocean; the first known specimen was first discovered in 1980 at a depth of in the Izu–Ogasawara Trench, Ogasawara Trench, off the coast of Japan and described in 1982 by a joint research team from the University of Copenhagen and the University of Tokyo. Further specimens referred to ''Occultammina'' sp. have been found at a depth of in the Porcupine Abyssal Plain, in the North Atlantic. Further studies have expanded its geographical and bathymetric range from in the Ogasawara Trench and from in the North Atlantic, and also recorded its presence at in the Japan Trench, Japan trench. ''Occultammina'' sp. has also been rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
