''Zoophycos'' is a somewhat cosmopolitan

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. ''Ichnotaxa'' comes from the Greek ίχνος, ''ichnos'' meaning ''track'' and ταξις, ''taxis'' meaning ...

thought to be produced by moving and feeding polychaete worms.

Appearance

''Zoophycos'' occurs in two forms, one planar, and one which resembles a corkscrew. In the latter helicoidal form, successive turns have larger or smaller radii. A marginal tube surrounds the perimeter of the corkscrew, linked to the vertical shaft that connects the burrow to the surface. Spreiten occur between the marginal tube and the corkscrew axis. The burrows can exceed a metre in vertical and horizontal dimension.

Ethology

One hypothesis proposes that ''Zoophycos'' represents gardening behaviour, in a similar fashion to '' Palaeodictyon''. According to this view, there should be a fractionation of carbon isotopes between the burrow infills and the matrix – but such differentiation was not observed in Quaternary instances from deep-water cores off the Portuguese coast.(Variation in morphology between different zoophycos 'species' means that these may not be representative of ''all'' zoophycos instances.) Instead, increased concentration of organic carbon within burrows suggests that the burrows may have been used to cache food resources. Alternatively, the burrows may simply be deposit feeding traces.

Occurrence

Zoophycos gives its name to the Zoophycos

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 constra ...

, an assemblage of trace fossils which is associated with the

shelf break A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

.MacEachern JA, Bann KL, Pemberton SG, Gingras MK. 2009. The Ichnofacies Paradigm: High-Resolution Paleoenvironmental Interpretation of the Rock Record. In: MacEachern JA,, In: Bann KL,, In: Gingras MK,, In: Pemberton SG, eds. Applied Ichnology: SEPM Short Course Notes.27–64. Nevertheless, it is now appreciated that it has a somewhat more cosmopolitan occurrence that has changed through time. It is typically associated with deep marine muds and sands, often between

turbidite A turbidite is the geologic deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing Turbidites wer ...

beds. It is known from both the fossil record and deep sea sediment cores. However, it can also occur in shallow-marine storm deposits, and indeed in Moroccan deposits it seems only to occur in beds that have some form of storm-supplied sediment input. It occurs from the early Ordovician until the present. It is restricted to deep waters in the Silurian, but occurs in nearshore settings from the Devonian until the end of the Permian.

References

External links

* * {{Commons category, Zoophycos Trace fossils Paleozoic life of Quebec

Appearance

Ethology

Occurrence

See also

References

Further reading

External links