Compression fossil: Difference between revisions

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[[Image:FossilFernLeavesPennsylvanianOhio.jpg|thumb|Fossil [[seed fern]] leaves from the Late [[Carboniferous]] of northeastern [[Ohio]].]]

A '''''compression fossil''''' is a [[fossil]] preserved in [[sedimentary rock]] that has undergone [[compression (physical)|physical compression]]. While it is uncommon to find [[animal]]s preserved as good compression fossils, it is very common to find [[plant]]s preserved this way. The reason for this is that physical compression of the rock often leads to [[distortion]] of the fossil.

The best fossils of [[leaf|leaves]] are found preserved in fine layers of [[sediment]] that have been compressed in a direction [[perpendicular]] to the plane of the deposited sediment.<ref name="Arnold 1947"/> Since leaves are basically flat, the resulting distortion is minimal. [[Plant stem]]s and other three-dimensional plant structures do not preserve as well under compression. Typically, only the basic outline and surface features are preserved in compression fossils.; Internalinternal [[anatomy]] is not preserved. These fossils may be studied while still partially entombed in the sedimentary rock matrix where they are preserved, or once lifted out of the matrix by a peel or transfer technique.<ref name="Stewart 1993"/>

Compression fossils are formed most commonly in [[ecosystem|environment]]s where fine sediment is deposited, such as in [[river delta]]s, [[lagoon]]s, along [[river]]s, and in [[pond]]s. The best rocks in which to find these fossils preserved are [[clay]] and [[shale]], although [[volcanic ash]] may sometimes preserve plant fossils as well.<ref name="Taylor & Taylor 1993"/>

==References==

{{Reflist|2|refs=

* Taylor, Thomas N. & Taylor, Edith L. (1993). ''The Biology and Evolution of Fossil Plants''. Englewood Cliffs, NJ: Prentice Hall. ISBN 0-13-651589-4.

<ref name="Arnold 1947">{{cite book | last=Arnold | first=Chester A. | year=1947 | title=An Introduction to Paleobotany | edition=1st | ___location=New York & London | publisher=McGraw-Hill Book Company | pages=14-40 }}</ref>

<ref name="Stewart 1993">{{cite book | last1=Stewart | first1=Wilson N. | last2=Rothwell | first2=Gar W. |year=1993 | title=Paleobotany and the Evolution of Plants | edition=2nd | ___location=Cambridge | publisher=Cambridge University Press |isbn=0-521-38294-7 | pages=7-22 }}</ref>

*<ref name="Taylor, & Taylor 1993">{{cite book | last1=Taylor | first1=Thomas N. &| last2=Taylor, | first2=Edith L. (| year=1993). ''| title=The Biology and Evolution of Fossil Plants''. | ___location =Englewood Cliffs, NJ: | publisher=Prentice Hall. ISBN| isbn=0-13-651589-4. | pages=7-12 }}</ref>

}}

[[Category:Fossils]]