North American Micropaleontology Section - SEPM

What is Micropaleontology?

Micropaleontology is the field of study dealing with small fossils that are best studies with a microscope.  Microfossils include a wide variety of microscopic remains of single-celled organisms, plants and animals.


Foraminifera are tiny, amoeba-like single-celled organisms that commonly have shells. They are characterized by thread-like extensions of their protoplasm called reticulating pseudopodia. They typically live in marine environments, some types on the bottom (benthic) and some in the water column (planktic). Their shells may be preserved in sediments and thus provide a record of past environments. Many species are also useful biostratigraphic indicators, which provide en estimate of a sediment's age. More information is available at the University of California Museum of Paleontology web site     

Ostracodes are small, bivalved crustaceans that may range from a fraction of a millimeter to many millimeters in size. They have a long geologic history, ranging back into the Paleozoic Era, with a wide variety of species occupying a wide range of environments, from oceans to bays to lakes to soils. Their shells are readily fossilized, making them useful for biostratigraphy and paleoenvironmental analyses. More information is available at the University of California Museum of Paleontology web site

Conodonts are small, tooth-like phosphatic microfossils found in sedimentary rocks from the Paleozoic Era (and earliest Mesozoic Era). They are thought to be produced by an extinct jawless chordate that had some resemblance to eels. They are valuable biostratigraphic indicators; in addition, their color may be used to indicate the thermal history of s sedimentary rock. More information is available at the University College London web site
Pollen and Spores:

Pollen and spores provide a record of plant life in the past. Pollen are tiny grains produced by seed plants that contain the male reproductive cells of the plant. The organic-walled remains of pollen grains can be preserved in sediments and fossilized. Spores of non-seed producing plants such as ferns may also be preserved as organic-walled fossils. Because these types of grains may be produced in abundance by some land plants, palynology (the study of pollen, spores, and other organic-walled microfossils) can be useful for biostratigraphy and climate reconstruction, particularly in non-marine sediments. More information is available at the University of Arizona web site.

Nannofossils are the hard parts of single-celled golden-brown algae. These hard parts are extremely small calcite plates (called coccoliths) that are secreted by the algae as it grows. Calcareous nannofossils can be very abundant in the sediments at the bottom of the oceans of today and the past. More information is available at the US Geological Survey web page on nannofossils.


Dinoflagellates are a group of single-celled, flagellated algae, some of which are preserved as organic-walled microfossils; as such, they are included in the field of palynology. Dinoflagellates mostly live in marine environments Their fossils are useful for biostratigraphy and interpretation of coastal and oceanic paleoenvironments. More information is available at University of California Museum of Paleontology web site     

Radiolaria are minute, amoeba-like single-celled planktonic marine organisms that have intricate shells usually made of opaline silica. Their shells in ocean bottom sediments provide a useful record of climate and oceanography. More information is available at the web site

There are a number of other useful microfossil groups studied by micropaleontologists - diatoms, silicoflagellates, chitinozoans, among them. A search engine should yield a number of sites with helpful information.


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