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Helminthopsis01
''Helminthopsis'' is the ichnogenus of a type of trace fossil that is found preserved on the bedding planes of fine-grained sedimentary rocks. It is characterized by short, curvilinear, non-branching, parallel-sided, unlined traces on bedding surfaces. It is thought to represent the submarine feeding trails of an invertebrate organism that worked the surface of muddy substrates in search of food. Because ''Helminthopsis'' traces never cross over themselves, the ichnogenus is distinguished from similar traces assigned to the ''Gordia'' ichnogenus. The similar sounding, but now obsolete, ichnogenus ''Helminthoida'' refers to a somewhat similar trace characterized by regular, back-and-forth meanders, whereas ''Helminthopsis'' traces are irregular. See also * Trace fossil * Ichnology References Trace fossils {{trace-fossil-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Fossil
A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of parts of organisms' bodies, usually altered by later chemical activity or by mineralization. The study of such trace fossils is ichnology - the work of ichnologists. Trace fossils may consist of physical impressions made on or in the substrate by an organism. For example, burrows, borings ( bioerosion), urolites (erosion caused by evacuation of liquid wastes), footprints, feeding marks, and root cavities may all be trace fossils. The term in its broadest sense also includes the remains of other organic material produced by an organism; for example coprolites (fossilized droppings) or chemical markers (sedimentological structures produced by biological means; for example, the formation of stromatolites). However, most sedimentary struct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichnogenus
An ichnotaxon (plural ichnotaxa) is "a taxon based on the fossilized work of an organism", i.e. the non-human equivalent of an artifact. ''Ichnotaxon'' comes from the Ancient Greek (''íchnos'') meaning "track" and English , itself derived from Ancient Greek (''táxis'') meaning "ordering".Definition o'ichno'at dictionary.com. Ichnotaxa are names used to identify and distinguish morphologically distinctive ichnofossils, more commonly known as trace fossils (fossil records of lifeforms' movement, rather than of the lifeforms themselves). They are assigned genus and species ranks by ichnologists, much like organisms in Linnaean taxonomy. These are known as ichnogenera and ichnospecies, respectively. "Ichnogenus" and "ichnospecies" are commonly abbreviated as "igen." and "isp.". The binomial names of ichnospecies and their genera are to be written in italics. Most researchers classify trace fossils only as far as the ichnogenus rank, based upon trace fossils that resemble eac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sedimentary Rocks
Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedimentation is any process that causes these particles to settle in place. Geological detritus originates from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus is formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies ( marine snow). Sedimentation may also occur when dissolved minerals precipitate from water solution. The sedimentary rock cover of the continents of the Earth's crust is extensive (73% of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gordia
''Gordia'' is an ichnofossil A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ... known from Precambrian to modern sediments and is the most common trace fossil in the Kaili biota displaying "smooth, cylindrical or subcylindrical, non-branching, winding and irregularly curving burrows, commonly self-overcrossing". Probably made by a worm-like creature displaying fodinichnial (sediment scavenging) behaviour. It takes the form of unlined, curving parallel-walled burrows that often end with a nub, probably created as the creature probed the over- or under-lying sediment. It resembles '' Helminthopsis'' and '' Haplotichnus''. References Burrow fossils Invertebrate paleozoology {{trace-fossil-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helminthoida
''Nereites'' is an ichnogenus of trace fossil. Modern tracemakers of incipient ''Nereites'' include worm-like organisms,Seilacher, A., 2007. Trace Fossil Analysis. Springer, Berlin, Heidelberg (226 pp.) horseshoe crabsMartin, A.J., Rindsberg, A.K., 2007. Arthropod Tracemakers of Nereites? Neoichnological observations of juvenile limulids and their paleoichnological applications. In: Miller III, W. (Ed.), Trace Fossils. Concepts, Problems, Prospects. Elsevier, Amsterdam, pp. 478–491. and hermit crabs.Baucon A., Felletti F. 2013. Neoichnology of a barrier-island system: the Mula di Muggia (Grado lagoon, Italy). Palaeogeography, Palaeoclimatology, Palaeoecology 375. Abstract available from http://www.tracemaker.com Traditionally, two models have been proposed for ''Nereites'': # in the ‘worm model’, ''Nereites'' is a feeding burrow produced by wormlike organisms, probing and backfilling laterally # in the ‘arthropod model’, the characteristic lobes are pressure-release st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
