Paleoclimate Foraminifera

Foraminifera

 

Foraminifera are a large group of amoeboid protists with reticulating pseudo pods fine strands of cytoplasm that branch and merge to form a dynamic net. They typically produce a test or a shell, which can have either one or multiple chambers, some becoming quiet elaborate in structures. These shells are made up of calcium carbonate (CaCO3) or agglutinated sediment particles. About 275000 species are recognized, both living and fossil. They are usually less than 1 mm in size, but largest recorded specimen is about 19 cm.  Foraminifera have typically been included in the group Protozoa. The form and the composition of test is the primary means by which foraminifera are identified and classified. Foraminifera are abundant all over the ocean and found in all marine environments. They either live on the sea bottom (benthic) or float in the upper water column (planktonic). A few benthic species have been recorded from terrestrial environments including ground water.

 

 

Classification

The generally accepted classification of foraminifera is based on that of Loeblich and Tappan (1964). The order Foraminiferida (informally foraminifera) belongs to the:                                                                                                                                                                                 

Kingdom: Protista                                                                                        

Subkingdom:Protozoa                                                                                                       

Phylum: Sarcomastigophora                     

Subphylum: Sarcodina                   

Superclass: Rhizopoda                                                                                                     

Class: Granuloreticulosea

 

Life Cycle


Of the approximately 4000 living species of foraminifera the life cycles of only 20 or so are known. The life cycle is characterized by an alteration between two generations: a gamont generation which reproduces sexually, and an agamont generation which produces asexually.