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Gnathorhizidae
The Gnathorhizidae are an extinct family of lungfish that lived from the late Carboniferous until the middle Triassic. Gnathorhizid fossils have been found in North America, Madagascar, Australia, and possibly Eastern Europe and South Africa. They are characterized by high-ridged toothplates that form cutting blades and a reduction in cranial bones. Taxonomy Phylogenetic evidence supports Gnathorhizidae being the sister group to the extant family Lepidosirenidae, which still lives in South America and Africa. The clade containing Gnathorhizidae and Lepidosirenidae is the crown group of the suborder Ceratodontoidei, which also contains the extant family Neoceratodontidae and many other extinct families. Distribution Gnathorhizids are found in North America, Eastern Europe, Australia, and Africa. Gnathorhizids from North America range from the Gzhelian through the Roadian. In Africa, gnathorhizids are found in Olenekian of Madagascar and possibly South Africa. Lungfish t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lungfish
Lungfish are freshwater vertebrates belonging to the order Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton. Lungfish represent the closest living relatives of the tetrapods. Today there are only six known species of lungfish, living in Africa, South America, and Australia. The fossil record shows that lungfish were abundant since the Triassic. While vicariance would suggest this represents an ancient distribution limited to the Mesozoic supercontinent Gondwana, the fossil record suggests advanced lungfish had a widespread freshwater distribution and the current distribution of modern lungfish species reflects extinction of many lineages subsequent to the breakup of Pangaea, Gondwana and Laurasia. Lungfish have historically been referred to as salamanderfish, but this t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratodontoidei
Ceratodontoidei is a suborder of lungfish that is defined as "the clade including all taxa more closely related to ''Lepidosiren'', '' Neoceratodus'' and '' Gnathorhiza'' than to '' Uronemus'', '' Conchopoma'' and ''Sagenodus''". Members of this suborder are known as ceratodontoids. The only presently extant lungfish in the families Neoceratodontidae and Lepidosirenidae belong to this suborder. Taxonomy The suborder was formerly defined as being within the order Ceratodontiformes and including the families Neoceratodontidae and Ceratodontidae, as they were formerly thought to be closely related to one another. However, phylogenetic analyses indicate that this classification is paraphyletic, as Ceratodontidae was found to be a sister group to a clade containing Lepidosirenidae, which was formerly classified as Lepidosireniformes, a distinct order from Ceratodontiformes. Due to this, Lepidosireniformes and Ceratodontiformes were redefined as families within the order Dipnoi, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnathorhiza
''Gnathorhiza'' is an extinct genus of prehistoric lobe-finned fish (lungfish) which lived during the Permian period and Early Triassic epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided by .... References Prehistoric lungfish genera Permian bony fish Permian fish of North America Fossils of Poland {{Triassic-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beltanodus
''Beltanodus'' is an extinct genus of prehistoric lungfish which lived during the Triassic period The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period .... References Prehistoric lungfish genera Triassic fish of North America {{paleo-lobefinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namatozodia
''Namatozodia'' is an extinct genus of prehistoric lungfish. The genus, and its sole species, ''Namatozodia pitikanta'', are described in Kemp (1993). The only known example of the species and genus is a small skull found in the Arcadia Formation of the Crater, in Western Queensland, Australia. This is an early Triassic formation. Discovery and naming The holotype specimen, QM F15000, is a partial calvarium without associated tooth material found at the Crater, near Rolleston in western Queensland. The name ''Namatozodia'' is derived from the Greek ''namat-'', or fountain, and ''zodiaion'', a diminutive of animal. ''Pitikanta'' is an Aboriginal word for 'young' in a dialect local to the area the fossil was found. Description The known skull of ''Namatozodia'' is small, measuring only 7 millimeters by 3.5 millimeters, coming from an individual perhaps just 6 to 7 centimeters long, a size comparable to a juvenile Australian lungfish. However the skull bones are fully developed, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidosirenidae
Lepidosirenidae is a family of lungfish containing the genera ''Lepidosiren'' (the South American lungfish) and ''Protopterus'' (the African lungfish). Both genera were formerly thought to represent the distinct families Lepidosirenidae and Protopteridae within the order Lepidosireniformes, but a 2017 study analyzing all post-Devonian lungfish taxa found them to be better classified as different genera in a single family. Taxonomy Their closest living relatives are of the family Neoceratodontidae, or the Australian lungfish, with both families being members of the suborder Ceratodontoidei. However, their closest relatives in general are of the extinct Gnathorhizidae, which forms a sister group to Lepidosirenidae. The clade containing both families forms a sister group to the extinct family Ptychoceratodontidae. The earliest fossils of the family come from the Late Cretaceous (Campanian-Maastrichtian) of Sudan, but phylogenetic evidence indicates the two genera split at the ve ... [...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] |
Gzhelian
The Gzhelian ( ) is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from to Ma. It follows the Kasimovian age/stage and is followed by the Asselian age/stage, the oldest subdivision of the Permian system. The Gzhelian is more or less coeval with the Stephanian Stage of the regional stratigraphy of Europe. Name and definition The Gzhelian is named after the Russian village of Gzhel (russian: Гжель), nearby Ramenskoye, not far from Moscow. The name and type locality were defined by Sergei Nikitin (1850–1909) in 1890. The base of the Gzhelian is at the first appearance of the Fusulinida genera '' Daixina'', '' Jigulites'' and '' Rugosofusulina'', or at the first appearance of the conodont ''Streptognathodus zethus''. The top of the stage (the base of the Permian system) is at the first appearance of the conodont ''Streptognath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Despite a wide range of natural resources, Africa is the least wealthy continent per capita and second-least wealthy by total wealth, behind Oceania. Scholars have attributed this to different factors including geography, climate, tribalism, colonialism, the Cold War, neocolonialism, lack of democracy, and corruption. Despite this low concentration of wealth, recent economic expansion and the large and young population make Afr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants. The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten", and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979. Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen. Contents of the crown gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neoceratodontidae
Neoceratodontidae is a family of lungfish containing the extant Australian lungfish and several extinct genera. It and Lepidosirenidae represent the only lungfish families still extant. Fossils from this family are first known from Triassic-aged sediments in Kyrgyzstan, but phylogenetic evidence indicates that it first originated near the end of the Carboniferous period. Despite their name, they are in fact basal to the related genus ''Ceratodus ''Ceratodus'' (from el, κέρας , 'horn' and el, ὀδούς 'tooth') was a wide-ranging genus of extinct lungfish. Fossil evidence dates back to the Early Triassic. A wide range of fossil species from different time periods have been found ...'' (and thus diverged before ''Ceratodus'' did), rather than vice versa. References {{Taxonbar, from=Q10296196 Lungfish Extant Middle Triassic first appearances Fish families ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teeth
A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous fish, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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