Taphocenosis
A Taphozönose (alternative spelling: Taphocoenose ), also grave Community called, a collection called fossil preserved remnants of living beings , which at a certain location in the same sites within any layer of sediment - or sedimentary rock sequence occur. It is thus the remains of living beings that all lived in this region at roughly the same time in the geological past. The term taphocenosis overlaps with that of the fossil deposit , but the former is mainly used in a paleecological context, including the question of which species the fossil deposit contains and how many individuals each of these species is represented by. The term fossil deposit has more of a taphonomic connotation; H. he looks more closely at fossil accumulations in terms of the type and quality of fossil conservation.
According to the origin of the organism remains in relation to the place of embedding in the sediment - represented by the find layer at the place of discovery - two extreme forms of taphocenosis can be distinguished:
- Purely alien ( allochthonous ) taphocenoses consist exclusively of the remains of organisms that did not live at the place of embedding, but were transported there - mostly by flowing water - from their actual habitat. In such cases, the fossils often show clear signs of transport, especially breakage, rounding of edges and disarticulation (the complete dismantling of complex skeletons - for example of vertebrates or echinoderms - into their individual parts and mixing them together so that there is no longer an anatomical connection) . The allochthonous taphocenosis corresponds to the fossil deposit type concentrate deposit .
- Purely local ( autochthonous ) taphocenoses exclusively comprise the remains of organisms that lived directly at the place of embedding and were not transported there. It is thus a biocenosis that has been handed down in situ , which is also known as thanatocoenosis (alternative spelling: thanatocoenosis ). In such fossil communities, sessile marine invertebrates are often passed down in a living position, i.e. standing upright (see also geopetal structure ), as is the case e.g. B. is typical of reef limestone . Regarding the fossil deposit type, real thanatocoenoses are only present in conserved deposits . A special and seldom occurring example of a thanatocenosis is the common transmission of numerous organism remains in a single amber , which is then referred to as a synincluse stone .
Whether a burial community is autochthonous or allochthonous can be important for the correct interpretation of the deposition environment . However, the interpretation should always be based on sedimentological and other features of the find horizon (the entirety of which is called facies ). Conversely, sedimentology in particular can provide clues as to whether a burial community is autochthonous or partially or completely allochthonous.
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General
- Taphozoenosis in spectrum online encyclopedia of geosciences
- Thanatocoenosis in spectrum online encyclopedia of geosciences