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Ophiomorpha
''Ophiomorpha'' is an ichnotaxon, usually interpreted as a burrow of an organism (specifically a crustacean) living in the near-shore environment. The burrow lining is more or less smooth on the inside, and densely to strongly mammalated or nodose on the outside, due to the packing of nodules for support of the burrow. Branching is irregular but Y-shaped where present. It (particularly ''O. nodosa'') is often considered part of the Skolithos ichnofacies, where it has occurred (i.e. nearshore environments) since the early Permian, though it (particularly ''O. rudis'') has also occurred in deep water settings (''Nereites'' ichnofacies) since the Late Jurassic, such as well-oxygenated turbidites. More generally ''Ophiomorpha ''and other crustacean-generated burrows first become prominent in the Jurassic. See also * Trace fossil * Ichnology A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved rem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichnofacies
An ichnofacies is an assemblage of trace fossils that provides an indication of the conditions that their formative organisms inhabited. Concept Trace fossil assemblages are far from random; the range of fossils recorded in association is constrained by the environment in which the trace-making organisms dwelt. Palaeontologist Adolf Seilacher pioneered the concept of ichnofacies, whereby the state of a sedimentary system at its time of deposition could be deduced by noting the trace fossils in association with one another. Significance Ichnofacies can provide information about water depth, salinity, turbidity and energy. In general, traces found in shallower water are vertical, those in deeper water are more horizontal and patterned. This is partly because of the relative abundance of suspended food particles, such as plankton, in the shallower waters of the photic zone, and partly because vertical burrows are more secure in the turbulent conditions of shallow water. In deepe ... [...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] |
Ichnotaxon
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] |
Skolithos
''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow with a distinct lining. It was produced globally by a variety of organisms, mostly in shallow marine environments, and appears as linear features in sedimentary rocks. Depositional environments ''Skolithos'' ranges in age from early Cambrian to the present and is found throughout the world. They occur in sediments and sedimentary rocks, primarily sands and sandstones. They are typically marine in origin, and are commonly associated with high-energy environments close to the shoreline. They have also been reported from freshwater lacustrine settings, but have rarely been described from carbonate rocks. Vertical ''Skolithos'' can also occur in alluvial sediments such as braided river deposits, where the periodic fluctuation of water is an important factor in the formation of this structure. This periodic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
