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Archaeomaenidae
Archaeomaenidae is an extinct family of stem- teleost fish found in freshwater environments of Jurassic New South Wales of Australia, China, and Antarctica, and in Lower Cretaceous New South Wales and Mongolia. Archaeomaenidae was originally erected by the Belgian zoologist George Albert Boulenger for the (then) two species of '' Archaeomaene'' (''A. tenuis'' and ''A. robustus'') of the Talbragar fishbeds, which had originally been assigned to the family Pholidophoridae. It was later expanded to include the other Talbragar fish genera ''Aetheolepis'' and '' Aphnelepis'' as well. In 1941, ''Archaeomaene robustus'' was moved to the new genus ''Madariscus'' by R. T. Wade; however, a 2021 study found that this species most likely represents mature individuals of ''Archaeomaene tenuis'', and is thus a junior synonym of it. Additionally, the archaeomaenid affinities of ''Aetheolepis'' and ''Aphnelepis'' have been questioned, with ''Aetheolepis'' more recently being interpreted as a mem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oreochima
''Oreochima ellioti'' is an archaeomaenid ray-finned fish from Lower Jurassic-aged freshwater strata of Antarctica. Fossils come from the Lower Jurassic Carapace Formation ( Pliensbachian-Toarcian) of Storm Peak, Antarctica, where a freshwater lake system once existed.Schaeffer, Bobb"A Jurassic Fish from Antarctica" American Museum of Natural History, 1972. ''O. ellioti'' is also notable for being one of three archaeomaenid genera found outside of Australia. Description Two nearly complete specimens of ''Oreochima ellioti'' (specimens AMNH 9910 and AMNH 9916) have an average total length of about 60 mm, with incomplete specimens represent individuals of similar size. The frontals taper anteriorly and were slightly notched where they were in contact with the nasals. The opercular bone was about twice as high as the subopercular. Paleoenvironment The interbeds of the Kirkpatrick Basalt record sedimentary and biotic processes in relatively shallow lakes and ponds, and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wadeichthys
''Wadeichthys oxyops'' is an extinct archaeomaenid bony fish from the Koonwarra Lake fauna of Lower Cretaceous Victoria, Australia Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in Au .... If the related genus '' Koonwarria'' is regarded as being in a different family, then ''W. oxyops'' is the only known Cretaceous-aged archaeomaenid. History/Palaeontology The fossils of the Wadeichthys species were excavated during extensive work on the Koonwarra fossil bed in Victoria. It is located approximately 145 kilometres southeast of Melbourne near Leongatha in South Gippsland and has been dated 115-118 million years old through fossils of fish, worms, bird feathers, fleas, spiders and crabs. The site was discovered in 1962 and was immediately recognised as an important site, known for "the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic-Jurassic extinction event, 201.3 Ma (million years ago), and ends at the start of the Middle Jurassic 174.1 Ma. Certain rocks of marine origin of this age in Europe are called "Lias Group, Lias" and that name was used for the period, as well, in 19th-century geology. In southern Germany rocks of this age are called Black Jurassic. Origin of the name Lias There are two possible origins for the name Lias: the first reason is it was taken by a geologist from an England, English quarryman's dialect pronunciation of the word "layers"; secondly, sloops from north Cornwall, Cornish ports such as Bude would sail across the Bristol Channel to the Vale of Glamorgan to load up with rock from coastal limestone quarries (lias limestone from S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Cretaceous
Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eighteen miles southwest of Gloucester and fifteen miles northeast of Bristol. Lower Wick is within the civil ... Gloucestershire, England See also * Nizhny {{Disambiguation ... [...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] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Analysis
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koonwarra, Victoria
Koonwarra is a town in the South Gippsland region of Victoria, Australia. At the , Koonwarra had a population of 404. The town straddles the South Gippsland Highway. Located around 128 km southeast of Melbourne, the town was served by rail from the 1890s until 1991 with the closing of the rail line to Barry Beach. Koonwarra fossil bed The Koonwarra fossil bed was found by accident in 1961 during roadworks to realign a segment of the South Gippsland Highway. Dating from the early Cretaceous 115 million years ago, it is composed of mudstone sediment thought to have been laid down in a freshwater (possibly cool-climate subalpine) lake. The site is an important element of Australia's fossil record, with plants, insects (including mayflies, dragonflies, cockroaches, beetles, fleas, flies and wasps), spiders, crustaceans and fish recovered. Among them is the unusual finding of a fossil horseshoe crab described as '' Victalimulus mcqueeni''. Small segments of a leafy twig have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koonwarria
''Koonwarria manifrons'' is an extinct genus of ray-finned fish that lived in a polar lake in what is now Koonwarra, Victoria, Australia during the Early Cretaceous epoch. Fossils have been retrieved from the Strzelecki Group.Waldman, Michael. Fish from the freshwater Lower Cretaceous of Victoria, Australia: with comments on the palaeo-environment. No. 9. Palaeontological Association, 1971/ref> ''Koonwarria manifrons'' shares many anatomical similarities with the family Archaeomaenidae, and is assumed to be descended from the archaeomaenids, but, is regarded as distinct enough to be placed in its own monotypic family, Koonwarriidae. References External links * Prehistoric teleostei Prehistoric ray-finned fish genera Cretaceous bony fish Early Cretaceous fish Early Cretaceous animals of Oceania Early Cretaceous Australia Cretaceous animals of Australia Freshwater fish genera † † A dagger, obelisk, or obelus is a typographical mark that usually indica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, making it the world's most sparsely populated sovereign nation. Mongolia is the world's largest landlocked country that does not border a closed sea, and much of its area is covered by grassy steppe, with mountains to the north and west and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to roughly half of the country's population. The territory of modern-day Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the First Turkic Khaganate, and others. In 1206, Genghis Khan founded the Mongol Empire, which became the largest contiguous land empire in history. His grandson Kublai Khan conquered China proper and established the Yuan dynasty. After the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dapediidae
Dapediidae is an extinct family of neopterygian ray-finned fish that lived during from the Late Triassic to Late Jurassic (Norian to Tithonian). It is the only family of the order Dapediiformes. Its members were historically placed within the ginglymodian family Semionotidae, but were moved to their own family in 1966. Description Dapediids had deep, laterally flattened circular bodies covered in thick ganoid scales, which gave them a resemblance to the pycnodontiforms, a group they may or may not be related to. Their teeth were adapted towards a durophagous diet; some dapediids fed on hard-shelled invertebrates, while at least one genus ('' Hemicalypterus'') may have been herbivorous. Classification Dapediids are usually considered to be either basal ginglymodians or stem group representatives of the wider clade Holostei, but some studies have found them to be early-diverging stem-teleost Teleostei (; Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
