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Bandringa
''Bandringa'' is an extinct genus of Elasmobranch known from the Pennsylvanian subperiod of the Carboniferous period that was part of the monotypic family Bandringidae. There is currently a single known species, ''B. rayi'', described in 1969.R. Zangerl. (1969). ''Bandringa rayi'': A New Ctenacanthoid Shark form the Pennsylvanian Essex Fauna of Illinois. ''Fieldiana Geology'' 12:157-169 It is known from exceptionally preserved individuals found in the Mazon Creek Lagerstätte of Illinois which dates back to the late Moscovian stage. Discovery and naming The holotype (PF 5686), a juvenile, was found by Ray Bandringa in an ironstone concretion in Illinois during the summer of 1967. By 1979, two species from this genus were originally described, ''B. rayi'' and ''B. herdinae'', but the differences between the two were found to be taphonomic in origin. All Mazon Creek individuals appear to represent juveniles, suggesting the area was a nursery for them. Also supporting this noti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bandringa SW
''Bandringa'' is an extinct genus of Elasmobranch known from the Pennsylvanian subperiod of the Carboniferous period that was part of the monotypic family Bandringidae. There is currently a single known species, ''B. rayi'', described in 1969.R. Zangerl. (1969). ''Bandringa rayi'': A New Ctenacanthoid Shark form the Pennsylvanian Essex Fauna of Illinois. ''Fieldiana Geology'' 12:157-169 It is known from exceptionally preserved individuals found in the Mazon Creek Lagerstätte of Illinois which dates back to the late Moscovian stage. Discovery and naming The holotype (PF 5686), a juvenile, was found by Ray Bandringa in an ironstone concretion in Illinois during the summer of 1967. By 1979, two species from this genus were originally described, ''B. rayi'' and ''B. herdinae'', but the differences between the two were found to be taphonomic in origin. All Mazon Creek individuals appear to represent juveniles, suggesting the area was a nursery for them. Also supporting this noti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mazon Creek Fossil Beds
The Mazon Creek fossil beds are a conservation ' found near Morris, in Grundy County, Illinois. The fossils are preserved in ironstone concretions, formed approximately in the mid- Pennsylvanian epoch of the Carboniferous period. These concretions frequently preserve both hard and soft tissues of animal and plant materials, as well as many soft-bodied organisms that do not normally fossilize. The quality, quantity and diversity of fossils in the area, known since the mid-nineteenth century, make the Mazon Creek ' important to paleontologists, in attempting to reconstruct the paleoecology of the sites. The locality was declared a National Historic Landmark in 1997.. Geology The Mazon Creek fossils are found in the Upper Carboniferous Francis Creek Shale; the type locality is the Mazon River (or Mazon Creek), a tributary of the Illinois River near Morris, Grundy County, Illinois. The 25 to 30 meters of shale were formed approximately , during the Pennsylvanian period. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allegheny Formation
The Pennsylvanian Allegheny Formation is a mapped bedrock unit in western and central Pennsylvania, western Maryland and West Virginia, and southeastern Ohio. It is a major coal-bearing unit in the Appalachian Plateau of the eastern United States and fossils of fishes such as ''Bandringa'' are known from the Kittaning Formation,R. Zangerl. (1969). ''Bandringa rayi'': A New Ctenacanthoid Shark form the Pennsylvanian Essex Fauna of Illinois. ''Fieldiana Geology'' 12:157-169 which is part of the Allegheny Group. Description In Pennsylvania, the Allegheny Formation includes rocks from the base of the Brooksville Coal to the top of the Upper Freeport Coal, and was defined to include all economically significant coals in the upper Pennsylvanian sequence. The formation consists of cyclothemic sequences of coal, shale, limestone, sandstone, and clay. It contains six major coal zones, which, in stratigraphic order, are: * Upper Freeport Coal * Lower Freeport Coal * Upper Kittanning Coal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods (or upper of two system (stratigraphy), subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronology, geochronologic units, the stratum, rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread. The division between Pennsylvanian and Mississippian (geology), Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian was in the past treated as a full-fledged geologic period between the Mississippian and the Permian. In parts of Europe, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmon
Salmon () is the common name for several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the family (biology), family Salmonidae, which are native to tributary, tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus ''Oncorhynchus'') basin. Other closely related fish in the same family include trout, Salvelinus, char, Thymallus, grayling, Freshwater whitefish, whitefish, lenok and Hucho, taimen. Salmon are typically fish migration, anadromous: they hatch in the gravel stream bed, beds of shallow fresh water streams, migrate to the ocean as adults and live like sea fish, then return to fresh water to reproduce. However, populations of several species are restricted to fresh water throughout their lives. Folklore has it that the fish return to the exact spot where they hatched to spawn (biology), spawn, and tracking studies have shown this to be mostly true. A portion of a returning salmon run ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenacanthiformes
Ctenacanthiformes is an extinct order of chondrichthyan fish. They possessed ornamented fin spines and cladodont dentition. Members of the family Ctenacanthidae may have survived into the Cretaceous based on teeth found in deep water deposits of Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceou ... age in France and Austria. References Prehistoric cartilaginous fish orders {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. Some species have wings. They are an extremely diverse group, with up to 10 million species. The haemocoel, an arthropod's internal cavity, through which its haemolymph – analogue of blood – circulates, accommodates its interior Organ (anatomy), organs; it has an open circulatory system. Like their exteriors, the internal or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sawfish
Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish with some species reaching lengths of about . They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes. They are endangered. They should not be confused with sawsharks (order Pristiophoriformes) or the extinct sclerorhynchoids (order Rajiformes) which have a similar appearance, or swordfish (family Xiphiidae) which have a similar name but a very different appearance. Sawfishes are relatively slow breeders and the females give birth to live young. They feed on fish and invertebrates that are detected and captured with the use of their saw. They are generally harmless to humans, but can inflict serious injuries with the saw when captured and defend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Feeding Mechanisms
Aquatic feeding mechanisms face a special difficulty as compared to feeding on land, because the density of water is about the same as that of the prey, so the prey tends to be pushed away when the mouth is closed. This problem was first identified by Robert McNeill Alexander. As a result, underwater predators, especially bony fish, have evolved a number of specialized feeding mechanisms, such as filter feeding, ram feeding, suction feeding, protrusion, and pivot feeding. Most underwater predators combine more than one of these basic principles. For example, a typical generalized predator, such as the cod, combines suction with some amount of protrusion and pivot feeding. Suction feeding Suction feeding is a method of ingesting a prey item in fluids by sucking the prey into the predator's mouth. It is a highly coordinated behavior achieved by the dorsal rotation of the dermatocranium, lateral expansion of the suspensorium, and the depression of the lower jaw and hyoid. Suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acipenseriformes
Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly derived, having only weakly ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls. Description The axial skeleton of Acipenseriformes is only partially ossified, with the majority of the bones being replaced with cartilage. The notochord, usually only found in fish embryos, is unconstricted and retained throughout life. The premaxilla and maxilla bones of the skull present in other vertebrates have been lost. The infraorbital nerve is carried by a series of separate canals, rather than being within the circumorbital bones. The palatoquadrate bones of the skull possess a cartilagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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