Echinoderm microfossil dating
Micropaleontology (also sometimes spelled as micropalaeontology) is the branch of palaeontology that studies microfossils, or fossils that require the use of a microscope to see the organism, its morphology and its characteristics details.
Diatomaceous earth is a soft, siliceous, sedimentary rock made up of microfossils in the form of the frustules (shells) of single cell diatoms.
Also, the planktonic and nektonic habits of some microfossils give them the bonus of appearing across a wide range of facies or paleoenvironments, as well as having near-global distribution, making biostratigraphic correlation even more powerful and effective.
Microfossils, particularly from deep-sea sediments, also provide some of the most important records of global environmental change on long, medium or short timescales.
Organic microfossils include pollen, spores, chitinozoans (thought to be the egg cases of marine invertebrates), scolecodonts ("worm" jaws), acritarchs, dinoflagellate cysts, and fungal remains.
Sediment or rock samples are collected from either cores or outcrops, and the microfossils they contain are extracted by a variety of physical and chemical laboratory techniques, including sieving, density separation by centrifuge or in heavy liquids, and chemical digestion of the unwanted fraction.
Microfossils are especially noteworthy for their importance in biostratigraphy.
Most researchers in this field, known as micropaleontologists, are typically specialists in one or more taxonomic groups.For example, some colonial organisms, such as Bryozoa (especially the Cheilostomata) have relatively large colonies, but are classified by fine skeletal details of the small individuals of the colony.In another example, many fossil genera of Foraminifera, which are protists are known from shells (called "tests") that were as big as coins, such as the genus Nummulites.Siliceous microfossils include diatoms, radiolarians, silicoflagellates, ebridians, phytoliths, some scolecodonts ("worm" jaws), and sponge spicules.
The study of organic microfossils is called palynology.
How microfossils were collected at Site #1 As previously noted, most road cuts are off limits to diggers.