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Helms Formation
The Helms Formation is a geologic formation in Texas and New Mexico. It preserves fossils dating back to the Chesterian (Serpukhovian) Age of the Carboniferous period. Description At its type section in the Hueco Mountains, the formation consists of of olive-gray shale, shaly sandstone, and dirty limestone. It is unconformably underlain by the Rancheria Formation and unconformably overlain by the La Tuna Formation. The formation also crops out in the Organ Mountains of New Mexico. The formation is interpreted as having been deposited during a marine regression (withdrawal of the sea from the continent) to the south. Fossils The formation contains fossils characteristic of the Chesterian (Serpukhovian) Age of the Carboniferous period. These include abundant specimens of the ostracod ''Graphiadactyllis arkansana'', as well as specimens of the bryozoan ''Archimedes terebriformis'', the echinoderm ''Pentremites'', the brachiopods ''Composita subquadrata'', ''Spiriferina tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ Mountains
The Organ Mountains (also known as La Sierra de los Órganos) are a rugged mountain range in southern New Mexico in the Southwestern United States. Organ Mountains–Desert Peaks National Monument was declared a national monument on May 21, 2014. They lie east of the city of Las Cruces, in Doña Ana County. Geography The Organ Mountains are near the southern end of a long line of mountains on the east side of the Rio Grande's rift valley. The range is nearly contiguous with the San Andres Mountains to the north and the Franklin Mountains to the south, but is very different geologically. Whereas the San Andres and Franklin Mountains are both formed from west-dipping fault blocks of mostly sedimentary strata (with limestone most prominent), the Organ Mountains are made primarily of igneous rock (intrusive granite and extrusive rhyolite). Their name reflects their similarity in appearance (particularly the granite "needles" in the highest part of the range) with pipes th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dictyoclostus
Productidina is a suborder of brachiopods containing the families: * Superfamily Productoidea ** Family Productellidae ** Family Productidae * Superfamily Echinoconchoidea ** Family Echinoconchidae ** Family Sentosiidae * Superfamily Linoproductoidea ** Family Linoproductidae ** Family Monticuliferidae References Strophomenata {{Brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diaphragmus
''Diaphragmus'' is an extinct genus of brachiopod belonging to the order Productida and family Linoproductidae. Specimens have been found in Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ... beds in North America. Classification Leighton & Maples (2002) conducted multiple phylogenetic analyses which are strongly in agreement that the four subfamilies Buxtoniinae, Echinoconchinae, Pustulinae and Juresaniinae form the family Echinoconchidae. The results of their phylogenetic analyses are displayed in the cladogram below: Species *''D. elegans'' Norwood and Pratten *''D. nivosus'' Gordon 1975 References Paleozoic animals Productida {{Brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiriferina
''Spiriferina'' is an extinct genus of brachiopods that lived from the Late Silurian to the Middle Jurassic in Asia, Europe, North America, South America, and New Zealand.''Spiriferina'' in the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms.
History
The Paleobiology Database (PBDB) originated in the NCEAS-funded Phanerozoic Marine Pale ...
Species The following species have been described: * ''[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composita
''Composita'' is an extinct brachiopod genus that lived from the Late Devonian to the Late Permian.''Composita'' at .org ''Composita'' had a cosmopolitan global distribution, having lived on every except . * ''Fossils'' (Smithsonian Handbooks) by David Ward (paleontologist), David Ward (Page 190) Blastozoa genera Carboniferous echinoderms of North America Fossils of Georgia (U.S. state) Paleozoic life of Alberta Paleozoic life of the Northwest Territories Paleozoic life of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Archimedes (bryozoan)
''Archimedes'' is a genus of bryozoans belonging to the family Fenestellidae. The first use of the term "Archimedes" in relation to this genus was in 1838. Etymology This genus of bryozoans is named ''Archimedes'' because of its corkscrew shape, in analogy to the Archimedes' screw, a type of water pump which inspired modern ship propellers in turn named after the ancient greek polymath. These forms are common as fossils but they have been extinct since the Permian. Species *''Archimedes orientalis'' Schulga-Nesterenko 1936 *''Archimedes regina'' Crockford 1947 *''Archimedes stuckenbergi ''Nikiforova 1938 Fossil range These bryozoans lived from the Carboniferous period (Tournaisian age) to the Permian period (Leonard age) (345.3 to 268.0 Ma), when this genus became extinct.Sepkoski, JacSepkoski's Online Genus Database - Bryozoa/ref> Description ''Archimedes'' is a genus of fenestrate bryozoans with a calcified skeleton of a delicate spiral-shaped mesh that was thickened n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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