Biostratinomy

The Biostratinomie (also Biostratonomie ) is the study of the unit and for arrangement of fossils in the rock. It covers all the operations on the individual from death to final embedding in the sediment.

Fossils can only arise when bodies, body parts or traces of organisms are not destroyed. This is often the case when embedding - but not if the organism at the surface remains. Dead bodies remain so over the long term only be maintained if they are protected from destruction by scavengers and physical forces by embedding in sediments such as sand, mud or ice.

It is important to distinguish whether the embedding autochthonous, that is in place, or allochthonous, follows a more or less wide postmortem transport to Fossilisationsort. Autochthonous embedded fossils are recovered in their habitat, through the analysis of the surrounding rock, can give its location in the layer sequence, etc. digestion. This is especially important because for the correct paleontological classification in addition to the mode of death, the manner of decomposition and embedding in particular, knowledge of the life of the animal and its relationship to its environment is important.

Preservation conditions for aquatic species or sessile animals are usually less expensive, resulting in a more frequent relative volume of such autochthonous fossils.

Allochthonous fossils often show strong distortions caused by acting during transport forces such as currents, gravity, buoyancy by putrefaction gases or browsing by scavengers. However, you may be rare references to residents of habitats with poor sedimentation, such as mountain and high altitude with strong erosion and debris formation or jungle areas on hard rock. Thus such fossil in which the carcass has not been embedded at the location at which the organism die. This results in a mountain range, for example, hardly fossils because the mountain yes subject to removal and usually after many millions of years completely disappears. You look for the living beings that inhabit the mountains, so you sometimes find them in former river courses, carried the water from the mountains. These fossils then show a pattern of severe devastation of the organism, which was worn over scree slopes and raging torrents down to the lowlands to be embedded only there in river mud.

Often, the transfer is carried for a long time existing mechanisms such as causing severe river flows or torrents in mountainous regions, resulting in many carcasses can accumulate on a narrowly defined area over time. Such revenue is referred to as Thanatocoenosen ( grave communities). They are of exceptional scientific value because they are home to numerous different species from a common time, so as a group photograph can be viewed. You then get an overview of the species that have lived together.

Important aspects biostratinomische

The arrangement of the bones in the rock. Not always, the bones get into that arrangement, in which they stood to each other in the skeleton - compact artefacts are found more rarely. Especially in allochthonous Thanatocoenosen occur before and during the embedding segregation, whereby body components sorted by shape, weight and hardness and can be relocated. In this Frachtsonderung numerous factors play a role under which the transportation condition and feeding animals on land as well as different floating ability, age or the flow conditions in aquatic habitats are important. The diagenesis then proceeds with the different parts in different ways. Especially confusing are sites that have been uncovered again after a temporary preservation, modified and embedded again. Often, sites are to be found, were embedded in the regulated selectively certain bones: ribs or teeth in large numbers.

One-step selection led to this specific accumulation of certain shapes and weights - often in a controlled arrangement, allow conclusions on embedding conditions. Mussel and snail shells are hereby directed from the water flow by dynamic laws. One speaks then - depending on the rotation axis - of Einkippung or steering of material in the archaeological site.

In Alaska, were so frequent that they interfered with the gold mining around the turn of the century mammoth hair that came from Eismumien, in rivers. There, where they accumulate, they could be placed again and fossilisieren final. Often discover fossil collectors unmanageable bone accumulations evaluated in a " mammoth work," must be compared and sorted. Must therefore be exercised in the salvage of fossil deposits special care in order to lose as little information due to carelessness As with the excavation of prehistoric human settlements.

Methods of Biostratinomie

The methods of Biostratinomie are taken closely related to those of the Fossilisationslehre and widely diversified from neighboring disciplines: biochemistry, biophysics, chemistry, geology, etc. A stand-alone method is the causal analysis. .

Causal analysis

Causal analysis of the origin of a fossil. Here, according to plausible point of all available information concerning the fossil, the environmental conditions at his death, rock type, etc. are evaluated and brought into causal relationships. This results in a history of the fossil.

Enumeration of abundances of fossils

Numerous well-preserved or evidence in the rock can be only due to conclusions about individuals or species richness of the relevant group of organisms. From a prolific volume in which many individuals of a species are found, can not be concluded that the species was very rich in individuals in their time. Conversely, it may also be that abundant species are rare or not the fossil record.

The probability of stored fossil with the inhabitants of different habitats vary with environmental conditions, which is exposed to the animal 's lifetime. Herein, a major drawback of fossils customer is visible, which can not be compensated with morphological methods such as the description and comparison of plans. Under certain circumstances, the presence of rare evidence of a morphological type of relatively large and important populations - even of species that played a central role in the later tribal history. (see also Missing Link )

It is also very likely that very many species that occurred locally or only briefly existed, never a document is found, because the information necessary for their detection rock layers are hidden in deep geological formations or have already been destroyed by exogenous forces. Some parts of former land or ocean floors are also hidden deep within the earth, where it slowly heated and melted or at least be changed lithologically. Fossils that are located there, lost forever and there is nothing they could bring back. Statistical projections, in the numerous plausible considerations need to be included, you will get only information about how great may be the particular tradition gap that we will not close.

Logical inference

Although the fossil photographer is very unfocused, light motifs preferred and neither their importance nor cares value on completeness of his photo albums deliberate, it is possible to hit through inference bridges. Their detection would be possible through inference based on available information about their ancestors or descendants, who were photographed randomly. Perhaps there has been in the earth's entire groups of organisms of which we attain knowledge never because no fossil evidence can be known. We can say that there must have been these groups of organisms but because she had ancestors and descendants, and are therefore not extinct in the absolute sense.

• Fossilization