What is Foraminifera?
[[File:Planktic Forams Late Pliocene.PNG|thumb|250px|A group of foram tests from the [[Pliocene]].]] [[File:Ammonia tepida.jpg|thumb|250px|A living foram]] '''Foraminifera''' or '''''forams''''', as they are called, are an important group of tiny single-celled [[rhizaria]]n [[eukaryote]]s. They are mostly [[Ocean|marine]], though a few live in fresh-water, and even on damp land areas. In the sea, they live both in the [[plankton]] ([[pelagic]]), and in the deeper water (the [[benthos]]). They have ''tests'' (like shells) made of [[calcium carbonate]] (CaCO<sub>3</sub>).<ref name=Hemleben>Hemleben C. Spindler M. & Anderson O.R. 1989. ''Modern planktonic Foraminifera''. Springer-Verlag, Berlin.</ref> The organism has [[Pseudopod|pseudopodia]] like an [[amoeba]]. It uses these to capture and eat [[bacteria]] and small [[diatom]]s. Also, many of them keep algal [[Endosymbiosis|endosymbionts]]. Some are ''idioplastic'', which means they eat the [[algae]], but keep the algal [[chloroplast]]s for their own benefit. Forams are often used to date [[strata]] in [[palaeontology]]. The detailed record of forams from deep sea drilling projects are the basis of a [[fossil]] index for [[Historical geology|geological period]]s or stages. This is called ''biostratigraphy''. Deep sea forams from the [[Mariana Trench]] are below the ''carbonate compensation depth'', below which all CaCO<sub>3</sub> dissolves. They have evolved organic tests, instead of calcium carbonate ones.<ref>Gooday A.J. Todo Y. Uematsu K. and Kitazato H. 2008. New organic-walled Foraminifera (Protista) from the ocean's deepest point, the Challenger Deep (western Pacific Ocean). ''Zoological Journal of the Linnean Society''. '''153''', 399–423.</ref> This suggests that the tests are a vital part of their life-style, perhaps protecting them from other micro-[[predator]]s. == References == {{Reflist}} [[Category:Fossils]] [[Category:Protista]]