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Bloyd Formation
The Bloyd Formation, or Bloyd Shale, is a geologic formation in Arkansas. It preserves fossils dating back to the Carboniferous period. Stratigraphy The Bloyd Formation conformably overlies the Hale Formation and unconformably underlies the Atoka Formation. Five formal and one informal members are recognized in the Bloyd Formation (in stratigraphic order): *Kessler Limestone Member *Dye Shale Member *Parthenon Sandstone Member (also known as the "middle Bloyd sandstone") *Woolsey Member *Baldwin coal (an informal unit at the top of the Woolsey Member) *Brentwood Limestone Member In the eastern parts of the Ozarks in Arkansas, the Bloyd Formation becomes undifferentiated with the underlying Hale Formation and is called the Witts Springs Formation. Paleontology Brachiopods *'' Anthracospirifer'' :''A. newberryi'' *'' Antiquatonia'' :''A. coloradoensis'' *'' Hustedia'' :''H. brentwoodensis'' *'' Linoproductus'' :''L. nodosus'' *'' Orthotetes'' *'' Rhynchopora'' :''R. magnicos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atoka Formation
Named after Atoka County, Oklahoma, the Atoka Formation is a geologic formation in central and western Arkansas, eastern Oklahoma, central and western Texas, and eastern New Mexico. It is the surface rock of the Boston Mountains and dominates exposures in the Frontal Ouachita Mountains of the Arkansas River Valley. Sedimentology The Atoka Formation is a sequence of marine sandstone, sandstones, siltstone, siltstones, and shale, shales, and may be as thick at 25,000 feet in the Ouachita Mountains. The formation is conformable with the Bloyd_Formation, Bloyd Shale in the Boston Mountains and the Johns Valley Formation in the Ouachita Mountains. Paleofauna Conodonts * ''Cavusgnathus'' : ''C. lauta'' : ''C. sinuata'' * ''Gnathodus'' : ''G. wapanuckensis'' * ''Gondolella'' : ''G. bella'' * ''Hindeodella'' * ''Ligonodina'' : ''L. lexingtonensis'' * ''Ozarkodina'' : ''O. recta'' * ''Polygnathodella'' : ''P. attenuata'' : ''P. ouachitensis'' * ''Streptognathodus'' : ''S. cancellosus'' : ... [...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 (geology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiquatonia
''Antiquatonia'' is an extinct genus of brachiopod belonging to the order Productida and family Productidae. Specimens have been found in Carboniferous beds across many continents, suggesting the genus had a cosmopolitan distribution. Species level taxonomy of ''Antiquatonia'' is in need of revision. Description Like other members of Productinae, ''Antiquatonia'' had a deep corpus cavity, a geniculate profile with long trails, and well-developed marginal structures such as ear baffles. This genus had thick, halteroid ventral spines. The ears were flanked by a ridge of ventral spines, with complimentary internal lateral ridges. Classification Muir-Wood & Cooper (1960) placed ''Antiquatonia'' in the subfamily Dictyoclostinae, though later analyses would find it to belong in Productinae instead. Leighton & Maples (2002) conducted multiple phylogenetic analyses which are strongly in agreement that ''Antiquatonia'' forms a clade with ''Diaphragmus ''Diaphragmus'' is an extinc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fenestella (bryozoan)
''Fenestella'' is a genus of bryozoans or moss animals, forming fan–shaped colonies with a netted appearance. It is known from the Middle Ordovician to the early Upper Triassic ( Carnian), reaching its largest diversity during the Carboniferous. Many hundreds of species have been described from marine sediments all over the world. Etymology ''Fenestella'' is Latin, meaning little window, from fenestra "window", for the window-like openings in the mesh of the skeleton of its colonies. Description The skeleton of ''Fenestella'' colonies consists of stiff branches that are interconnected by narrower crossbars (or dissepiments). Between two and eight individuals of the colony inhabit each of the opposing front sides of the approximately rectangular openings between the branches (or fenestule) in one row, and the void they left when they died can be recognized as two rows of small rimmed pores (or apertures) on the front of each branch. In well-preserved specimens these are c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. At least two genera are solitary (''Aethozooides'' and ''Monobryozoon''); the rest are colonial. The terms Polyzoa and Bryozoa were introduced in 1830 and 1831, respectively. Soon after it was named, another group of animals was discovered whose filtering mechanism looked similar, so it was included in Bryozoa until 1869, when the two groups were no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tesuquea
''Tesuquea'' is a genus of moths in the Carposinidae Carposinidae, the "fruitworm moths", is a family of insects in the order Lepidoptera. These moths are narrower winged than Copromorphidae, with less rounded forewing tips. Males often have conspicuous patches of scales on either surface (Dugdale ... family. It contains the single species ''Tesuquea hawleyana'', which is found in the southern United States, including New Mexico. The wingspan is about 14 mm. References Natural History Museum Lepidoptera generic names catalog Carposinidae {{Copromorphoidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
