Dip into the past with ForaminiferaThese little shell-shaped beauties are Foraminifera under a micro
Dip into the past with ForaminiferaThese little shell-shaped beauties are Foraminifera under a microscope. They are not only beautiful but fascinating and useful tiny organisms with a huge story to tell.Both living and fossil varieties of Foraminifera exist, they belong to the Rhizaria; a group of single celled organisms in the domain of eukaryotes (organisms whose cells contain a nucleus, for those of you who are not familiar with biological classification). Out of 10,000 known species a little more than 80% are still found alive in the marine ecosystem. Most living species are found in or on the seafloor sediment living benthically and a smaller part is marine aquatic plankton floating in the water. Even though molecular data suggest that they are probably a lot older Foraminifera are known as fossils as far back as the Cambrian period (560 Ma).Foraminefra occur in a variety of shapes and sizes, varying from 40 micrometers up to as much as 20 centimeters, although most species are at the small end. Fossil Foraminifera are widespread and their morphology is complex. For that reason these little fossils play an important role in biostratigraphy, a branch of stratigraphy in which relative ages of rocks are determined by means of fossil assemblages contained within them. Because their shells are commonly well-preserved, a huge amount of information can be read out of borehole samples. Therefore Foraminifera are used to define and identify geologic periods and have a huge impact when it comes to determine the age of rocks or telling us more about the environment and its conditions under which they formed.By examining the abundances of specific trace elements in foram shells, even more information can be revealed, such as the history of the carbon cycle or ancient global temperatures. Living Foraminifera in modern coastal environments or coral reefs say a lot about the condition and health of the ecosystems in those regions and are therefore used as so called bioindicators (species used to monitor the health of an environment or ecosystem).-CéImage Credit:http://commons.wikimedia.org/wiki/File:Foraminifères_de_Ngapali.jpgRudolf Röttger, Gunnar Lehmann: Benthic foraminifera In: R. Röttger, R. Knight, W. Foissner (Hrsg.): A course in Protozoology, Protozoological Monographs Bd. 4, 2009, S. 111–123http://www.marinespecies.org/foraminifera/http://www.newscientist.com/article/mg19826553.500-sea-creatures-had-a-thing-for-bling.html -- source link
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