Land plants

The fossil record of plants is typically fragmentary. Generally, plants have a low preservation potential and assemblages are usually composed entirely of disarticulated material. During their life cycle plants may shed some of their component parts. Other plants become broken up or fragmented due to tapho-nomic processes. As a result, separate parts of the same plant are often assigned to different organ genera (Fig. 12.1). The extent of plant preservation is dependent on the morphology and biology ofthe plant and different plant parts have different preservation potentials.

Plant material is often preserved when the pressure of accumulated sediments compresses it, resulting in the removal of the soluble plant components and reducing the material to a thin carbon film. These compression fossils are common in non-marine, deltaic environments. Further modification may result in the complete loss of organic material and only an impression of the plant may remain. Plant fossils, therefore, may have an impression and a compression surface. The way in which the rock splits determines the type of fossil. Plant material may also be preserved as molds or casts. More rarely,

Lepidodendron Stem Anatomy
Fig. 12.1 Lepidodendron reconstruction (height 50 m).

plant material is preserved through perimineralization or petrification. Mineral-saturated fluids infiltrate the cells and intercellular spaces. Subsequent crystallization reveals the internal structure of the plant parts.

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  • tarquinia
    What are the classification of plant fossils?
    9 months ago

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