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Elphidium Taiwanum
''Elphidium'' is an abundant genus of foraminifera. Species can be found from coastal regions out to the continental slope, and in all temperature ranges. Like other forams, fossils from different species are used to date rocks. The taxonomy of the species within this genus is disputed due to the high variability of some species. Description ''Elphidium'' is generally around 1 mm in size. The test is spiral-shaped, and can be red, orange, or brown. This shell is made up of calcium carbonate. Species of this genus have seven to twenty chambers in the final whorl, and may have an umbilical plug on each side. In some species the rim is sharp, while in others it is more rounded. Another distinctive feature is the retral processes (small backward extensions of the chamber walls) that cross the sutures, giving some the appearance of tiny rolled up glass baskets. ''Elphidium'' crawls using a type of pseudopod called reticulopodia. Life cycle ''Elphidium'' shows dimorphism with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
