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; internal [[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"/>