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Euctenius
''Euctenius'' is an extinct genus of vertebrate containing a single species, ''Euctenius unilateralis''. It was initially described as the tooth of the petalodont genus ''Ctenoptychius'' or as a genus of edestid, although it more likely represents the copulatory organ of an amphibian. Fossils of ''Euctenius'' have been uncovered in Scotland and England and date to the Late Carboniferous period. Identical structures are known to have been paired around the cloaca of Opiderpetonids and were most likely used to clasp while mating. The edge of the structure is finely serrated Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pr ..., and it is covered in enamel. References Edestidae Pennsylvanian vertebrates of Europe Monotypic prehistoric cartilaginous fish genera {{paleo-h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edestidae
The Edestidae are a poorly known, extinct Family (biology), family of shark-like eugeneodontid holocephalid cartilaginous fish. Similar to the related family Helicoprionidae, members of this family possessed a unique "tooth-whorl" on the symphysis of the lower jaw and pectoral fins supported by long radials. In addition to having a tooth-whorl on the lower jaw, at least one species of the genus ''Edestus'' had a second tooth-whorl in the upper jaw. The palatoquadrate was either fused to the skull or reduced. Edestids, along with the rest of the Eugeneodontida, are placed within the subclass (biology), subclass Holocephali. The family disappeared in the Early Triassic. References External linksPalaeos Vertebrates 70.100 Chondrichthyes: Eugnathostomata Paleos.comat paleos.comJSTOR: Journal of PaleontologyVol. 70, No. 1 (Jan., 1996), pp. 162-165 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods of the Carboniferous Period (or the upper of two system (stratigraphy), subsystems of the Carboniferous System). 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 Bed (geology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrate
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebrata with some 65,000 species, by far the largest ranked grouping in the phylum Chordata. The vertebrates include mammals, birds, amphibians, and various classes of fish and reptiles. The fish include the jawless Agnatha, and the jawed Gnathostomata. The jawed fish include both the Chondrichthyes, cartilaginous fish and the Osteichthyes, bony fish. Bony fish include the Sarcopterygii, lobe-finned fish, which gave rise to the tetrapods, the animals with four limbs. Despite their success, vertebrates still only make up less than five percent of all described animal species. The first vertebrates appeared in the Cambrian explosion some 518 million years ago. Jawed vertebrates evolved in the Ordovician, followed by bony fishes in the Devonian. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petalodontiformes
Petalodontiformes ("thin-plate teeth") is an extinct order of marine cartilaginous fish related to modern day chimaera found in what is now the United States of America and Europe.Lund, Richard, E. D. Grogan, and M. Fath. "On the relationships of the Petalodontiformes (Chondrichthyes)." Paleontological Journal 48.9 (2014): 1015-1029. Most species are known only from isolated teeth.Dalla Vecchia, Fabio Marco, and Museo Paleontologico Cittadino. "A new petalodont tooth (Chondrichthyes, Petalodontiformes) from the Lower Permian of the Carnic Alps (Friuli, NE Italy)." Bollettino della Società Paleontologica Italiana 39 (2000): 225-228. All fossils range from the Carboniferous to the Permian, where they are presumed to have died out during the Permian/Triassic extinction event. The two best known species are '' Belantsea montana'', from the Carboniferous Bear Gulch, Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenoptychius
''Ctenoptychius'' (meaning "comb-folded", from the Greek language, Greek wiktionary:cteno-, κτείς or ''kteís'' meaning "comb" and wiktionary:πτυχή#Ancient_Greek, πτυχή or ''ptychos'' meaning "fold") is an extinct genus of Chondrichthyes, cartilaginous fish in the order Petalodontiformes. While ''Ctenoptychius'' was historically thought to encompass a large number of species with Serration, serrated Crown (tooth), tooth crowns, it is now considered to include only the type species, ''C. apicalis''. This species lived during the Pennsylvanian (geology), Late Carboniferous period, and its fossils are known from the United Kingdom and potentially the United States. ''C. apicalis'' is known primarily from teeth, which have a flattened shape and serrated edges, although poorly-preserved specimens preserving the head, pectoral fins and Fish scale, scales of the body are also known. Based on this, it is believed that ''Ctenoptychius'' had a flattened, Batomorphi, ray-like b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Organ
A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting gametes, as well as facilitating fertilization and supporting the development and birth of offspring. Sex organs are found in many species of animals and plants, with their features varying depending on the species. Sex organs are typically differentiated into male and female types. In animals (including humans), the male sex organs include the testicles, epididymis, epididymides, and penis; the female sex organs include the clitoris, Ovary, ovaries, oviducts, and vagina. The testicle in the male and the ovary in the female are called the ''primary sex organs''. All other sex-related organs are known as ''secondary sex organs''. The outer parts are known as the genitals or external genitalia, visible at birth in both sexes, while the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibian
Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excluding the amniotes (tetrapods with an amniotic membrane, such as modern reptiles, birds and mammals). All extant taxon, extant (living) amphibians belong to the monophyletic subclass (biology), subclass Lissamphibia, with three living order (biology), orders: Anura (frogs and toads), Urodela (salamanders), and Gymnophiona (caecilians). Evolved to be mostly semiaquatic, amphibians have adapted to inhabit a wide variety of habitats, with most species living in freshwater ecosystem, freshwater, wetland or terrestrial ecosystems (such as riparian woodland, fossorial and even arboreal habitats). Their biological life cycle, life cycle typically starts out as aquatic animal, aquatic larvae with gills known as tadpoles, but some species have devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotland
Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjacent Islands of Scotland, islands, principally in the archipelagos of the Hebrides and the Northern Isles. To the south-east, Scotland has its Anglo-Scottish border, only land border, which is long and shared with England; the country is surrounded by the Atlantic Ocean to the north and west, the North Sea to the north-east and east, and the Irish Sea to the south. The population in 2022 was 5,439,842. Edinburgh is the capital and Glasgow is the most populous of the cities of Scotland. The Kingdom of Scotland emerged as an independent sovereign state in the 9th century. In 1603, James VI succeeded to the thrones of Kingdom of England, England and Kingdom of Ireland, Ireland, forming a personal union of the Union of the Crowns, three kingdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It shares Anglo-Scottish border, a land border with Scotland to the north and England–Wales border, another land border with Wales to the west, and is otherwise surrounded by the North Sea to the east, the English Channel to the south, the Celtic Sea to the south-west, and the Irish Sea to the west. Continental Europe lies to the south-east, and Ireland to the west. At the 2021 United Kingdom census, 2021 census, the population was 56,490,048. London is both List of urban areas in the United Kingdom, the largest city and the Capital city, capital. The area now called England was first inhabited by modern humans during the Upper Paleolithic. It takes its name from the Angles (tribe), Angles, a Germanic peoples, Germanic tribe who settled du ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloaca
A cloaca ( ), : cloacae ( or ), or vent, is the rear orifice that serves as the only opening for the digestive (rectum), reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilaginous fish and a few mammals ( monotremes, afrosoricids, and marsupial moles, etc.) have this orifice, from which they excrete both urine and feces; this is in contrast to most placental mammals, which have separate orifices for evacuation and reproduction. Excretory openings with analogous purpose in some invertebrates are also sometimes called cloacae. Mating through the cloaca is called cloacal copulation and cloacal kissing. The cloacal region is also often associated with a secretory organ, the cloacal gland, which has been implicated in the scent-marking behavior of some reptiles, marsupials, amphibians, and monotremes. Etymology The word is from the Latin verb ''cluo'', "(I) cleanse", thus the noun ''cloaca'', " sewer, drain" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiderpeton
''Ophiderpeton'' (from , 'snake' and 'creeper') is an extinct genus of aistopod tetrapodomorphs from the early Carboniferous to the early Permian. Remains of this genus are widespread and were found in Ohio, United States, Ireland, and the Czech Republic (Central Europe). Like other aistopods, ''Ophiderpeton'' was snake-like, without any trace of limbs. Its body was about long, with 230 vertebrae. The skull measured , and large, forward-facing eyes, suggesting a hunting lifestyle. It probably lived in burrows, feeding on insects, worms, millipedes, and snails. Many species are classified in the genus, and similar animals, '' Phlegethontia'' and '' Sillerpeton'', are known. An earlier genus, '' Lethiscus'', is known from the Carboniferous and Early Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Perio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serration
Serration is a saw-like appearance or a row of sharp or tooth-like projections. A serrated cutting edge has many small points of contact with the material being cut. By having less contact area than a smooth blade or other edge, the applied pressure at each point of contact is greater, and the points of contact are at a sharper angle to the material being cut. This causes a cutting action that involves many small splits in the surface of the material being cut, which cumulatively serve to cut the material along the line of the blade. Serration in nature In nature, serration is commonly seen in the cutting edge on the teeth of some species, usually sharks. However, it also appears on non-cutting surfaces, for example, in botany where a toothed leaf margin or other plant part, such as the edge of a carnation petal, is described as being serrated. A serrated leaf edge may reduce the force of wind and other natural elements. Probably the largest serrations on Earth occur on the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
