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Colosteidae
Colosteidae is a family of stegocephalians (tetrapod-like vertebrates) that lived in the Carboniferous period. They possessed a variety of characteristics from different tetrapod or stem-tetrapod groups, which made them historically difficult to classify. They are now considered to be part of a lineage intermediate between the earliest Devonian terrestrial vertebrates (such as '' Ichthyostega''), and the different groups ancestral to all modern tetrapods, such as temnospondyls (probably ancestral to modern amphibians) and reptiliomorphs (ancestral to amniotes such as mammals, reptiles, and birds). Description Colosteids had elongated bodies, with an estimated 40 vertebrae, not including the tail. The skull is flat and composed of many separate bones, like that of other stegocephalians. Colosteids lacked otic notches at the back of the head, unlike temnospondyls and other "labyrinthodont "Labyrinthodontia" (Greek, 'maze-toothed') is an informal grouping of extinct predatory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegocephalia
Stegocephali (often spelled Stegocephalia) is a group containing all four-limbed vertebrates. It is equivalent to a broad definition of Tetrapoda: under this broad definition, the term "tetrapod" applies to any animal descended from the first vertebrate with limbs and toes, rather than fins. This includes both the modern lineage of limbed vertebrates (the crown group, including modern amphibians, mammals, reptiles and birds) as well as a portion of the stem group, limbed vertebrates that evolved prior to the origin of the crown group. Members of the tetrapod stem group include the earliest limbed tetrapodomorphs such as '' Ichthyostega'' and ''Acanthostega,'' which evolved in the Devonian Period long before any modern form of tetrapod. Many paleontologists prefer a stricter definition of Tetrapoda which applies solely to the crown group, excluding earlier types of limbed tetrapodomorphs. Stegocephali was re-established to replace the broad definition of Tetrapoda, resolving t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deltaherpeton
''Deltaherpeton'' is an extinct genus of colosteid from middle Mississippian (late Viséan age) deposits of Delta, Iowa, United States. It was first named by John R. Bolt and R. Eric Lombard in 2010 and the type species is ''Deltaherpeton hiemstrae''. ''Deltaherpeton'' can be differentiated from other colosteids due to possessing several unique bones along the midline of the skull, separating paired skull bones which typically contact each other along the midline. These include an internasal, an oval-shaped bone which lies at the intersection of the paired premaxillae and nasal bones at the top of the snout. Internasals are known from several of the earliest four-limbed vertebrates, such as ''Acanthostega'', '' Ichthyostega'', and baphetids. Further back, what seems to be a pair of lozenge-shape bones lie at the intersection of the nasal bones and frontal bones. These bones may be interfrontonasals, which have been found in some eryopoids and microsaurs. In addition, '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegocephalia
Stegocephali (often spelled Stegocephalia) is a group containing all four-limbed vertebrates. It is equivalent to a broad definition of Tetrapoda: under this broad definition, the term "tetrapod" applies to any animal descended from the first vertebrate with limbs and toes, rather than fins. This includes both the modern lineage of limbed vertebrates (the crown group, including modern amphibians, mammals, reptiles and birds) as well as a portion of the stem group, limbed vertebrates that evolved prior to the origin of the crown group. Members of the tetrapod stem group include the earliest limbed tetrapodomorphs such as '' Ichthyostega'' and ''Acanthostega,'' which evolved in the Devonian Period long before any modern form of tetrapod. Many paleontologists prefer a stricter definition of Tetrapoda which applies solely to the crown group, excluding earlier types of limbed tetrapodomorphs. Stegocephali was re-established to replace the broad definition of Tetrapoda, resolving t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temnospondyl
Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order (biology), order of small to giant tetrapods—often considered Labyrinthodontia, primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Jurassic and Cretaceous periods. Fossils have been found on every continent. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are considered amphibians, many had cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elpistostegalia
Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Middle Devonian to Late Devonian period (about 385 to 374 million years ago). They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian ''Tiktaalik''. Through a strict cladistic view, the order includes the terrestrial tetrapods. Palaeobiology of the elpistostegalians A rise in global oxygen content allowed for the evolution of large, predatory fish that were able to exploit the shallow tidal areas and swamplands as top predators. Several groups evolved to fill these niches, the most successful were the elpistiostegalians. In such environments, they would have been challenged by periodic oxygen deficiency. In comparable modern aquatic environments l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greererpeton
''Greererpeton burkemorani'' ("crawler from Greer, West Virginia") is an extinct genus of colosteid stem-tetrapods from the Early Carboniferous period (late Viséan) of North America. ''Greererpeton'' was first described by famed vertebrate paleontologist Alfred S. Romer in 1969. The skull was redescribed by Timothy R. Smithson in 1982, while postcranial remains were redescribed by Stephen J. Godfrey in 1989. ''Greererpeton'' were probably aquatic, with an elongated body adapted for swimming. Adults have overall length of or , similar in size to modern Asian giant salamanders (''Andrias''). The body was elongated, with about 40 vertebrae, while the flattened skull reached about long in adult specimens. The most complete adult specimen only preserved 12 tail vertebrae, only about a third the length of the body as in ''Andrias''. However, smaller specimens have been found preserving over 30 vertebrae, so it is not inconceivable that a complete tail was approximately as long a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elpistostege
''Elpistostege'' is an extinct genus of finned tetrapodomorphs that lived during the late Givetian to early Frasnian ages of the Late Devonian epoch. Its only known species, ''E. watsoni'', was first described in 1938 by the British palaeontologist Thomas Stanley Westoll, based on a single partial skull roof discovered at the Escuminac Formation in Quebec, Canada. In 2010, a complete specimen was found in the same formation, which was described by Richard Cloutier and colleagues in 2020. It reveals that the paired fins of ''Elpistostege'' contained bones homologous to the phalanges (digit bones) of modern tetrapods; it is the most basal tetrapodomorph known to possess these bones. At the same time, the fins were covered in scales and lepidotrichia (fin rays), which indicates that the origin of phalanges preceded the loss of fin rays, rather than the other way around. Relationships An analysis conducted by Swartz in 2012 found ''Elpistostege'' to be the sister taxon of ''Tiktaa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct therapsids and all extant mammals). Tetrapods evolved from a clade of primitive semiaquatic animals known as the Tetrapodomorpha which, in turn, evolved from ancient lobe-finned fish (sarcopterygians) around 390 million years ago in the Middle Devonian period; their forms were transitional between lobe-finned fishes and true four-limbed tetrapods. Limbed vertebrates (tetrapods in the broad sense of the word) are first known from Middle Devonian trackways, and body fossils became common near the end of the Late Devonian but these were all aquatic. The first crown-tetrapods (last common ancestors of extant tetrapods capable of terrestrial locomotion) appeared by the very early Carboniferous, 350 million years ago. The specific aquatic ancestors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyostega
''Ichthyostega'' (from el, ἰχθῦς , 'fish' and el, στέγη , 'roof') is an extinct genus of limbed tetrapodomorphs from the Late Devonian of Greenland. It was among the earliest four-limbed vertebrates in the fossil record, and was one of the first with weight-bearing adaptations for terrestrial locomotion. ''Ichthyostega'' possessed lungs and limbs that helped it navigate through shallow water in swamps. Although ''Ichthyostega'' is often labelled a 'tetrapod' due to the possession of limbs and fingers, it evolved long before true crown group tetrapods, and could more accurately be referred to as a stegocephalian or stem tetrapod. Likewise, while undoubtedly of amphibian build and habit, it is not considered a true member of the group in the narrow sense, as the first modern amphibians (members of the group Lissamphibia) appeared in the Triassic Period. Until finds of other early stegocephalians and closely related fishes in the late 20th century, ''Ichthyostega'' st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ''Carboniferous'' means "coal-bearing", from the Latin '' carbō'' ("coal") and '' ferō'' ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern 'system' names, it was coined by geologists William Conybeare and William Phillips in 1822, based on a study of the British rock succession. The Carboniferous is often treated in North America as two geological periods, the earlier Mississippian and the later Pennsylvanian. Terrestrial animal life was well established by the Carboniferous Period. Tetrapods (four limbed vertebrates), which had originated from lobe-finned fish during the preceding Devonian, became pentadactylous in and diversified during the Carboniferous, including early amphibian line ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Premaxilla
The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has been usually termed as the incisive bone. Other terms used for this structure include premaxillary bone or ''os premaxillare'', intermaxillary bone or ''os intermaxillare'', and Goethe's bone. Human anatomy In human anatomy, the premaxilla is referred to as the incisive bone (') and is the part of the maxilla which bears the incisor teeth, and encompasses the anterior nasal spine and alar region. In the nasal cavity, the premaxillary element projects higher than the maxillary element behind. The palatal portion of the premaxilla is a bony plate with a generally transverse orientation. The incisive foramen is bound anteriorly and laterally by the premaxilla and posteriorly by the palatine process of the maxilla. It is formed from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cauliflower
Cauliflower is one of several vegetables in the species ''Brassica oleracea'' in the genus ''Brassica'', which is in the Brassicaceae (or mustard) family. It is an annual plant that reproduces by seed. Typically, only the head is eaten – the edible white flesh sometimes called "curd" (with a similar appearance to cheese curd). The cauliflower head is composed of a white inflorescence meristem. Cauliflower heads resemble those in broccoli, which differs in having flower buds as the edible portion. ''Brassica oleracea'' also includes broccoli, Brussels sprouts, cabbage, collard greens, and kale, collectively called "cole" crops, though they are of different cultivar groups. History Pliny the Elder included ''cyma'' among cultivated plants he described in '' Natural History'': "''Ex omnibus brassicae generibus suavissima est cyma,''" ("Of all the varieties of cabbage the most pleasant-tasted is ''cyma''"). Pliny's description likely refers to the flowering heads of an earli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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