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Xiangshuiosteus Wui
''Xiangshuiosteus wui'' is an extinct monospecific genus of brachythoracid arthrodire placoderm from the Late Emsian stage of the Early Devonian epoch, discovered in Wuding County of Yunnan province, China. It has recently been reassessed as a dunkleosteid. Etymology The generic name literally translates as "(Pinyin:Xiāngshuǐ) + bone," but actually refers to Xiangshui Valley,Not to be confused with Xiangshui County ()(Pinyin:Xiǎng shuǐ) in Jiangsu province the district in Wuding County where the holotype was found. The specific name honors Wu Baosheng, the gentleman who provided the holotype to Wang Junqing, the species' describer. Specimen and taxonomy ''X. wui'' is known from a flattened, "Buddhist cap" shaped skull roof. The skull roof is strongly reminiscent of those of coccosteids, but also has anatomical features otherwise diagnostic of buchanosteids. This mix of anatomy lead its describer, Wang Junqing, to suggest that ''X. wui'' is the sister taxon of Coccosteid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Devonian
The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the Pragian from and then by the Emsian, which lasted until the Middle Devonian began, . During this time, the first Ammonoidea, ammonoids appeared, descending from Bactritida, bactritoid Nautiloidea, nautiloids. Ammonoids during this time period were simple and differed little from their nautiloid counterparts. These ammonoids belong to the order Agoniatitida, which in later epochs evolved to new ammonoid orders, for example Goniatite, Goniatitida and Clymeniida. This class of cephalopod molluscs would dominate the marine fauna until the beginning of the Mesozoic Era. References {{Geological history Early Devonian, Geological epochs Devonian geochronology, *01 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertebrata PalAsiatica
The Institute of Vertebrate Paleontology and Paleoanthropology (IVPP; ) of China is a research institution and collections repository for fossils, including many dinosaur and pterosaur specimens (many from the Yixian Formation). As its name suggests, research is focused on both paleontological topics and those relating to human prehistory. The institution, located in Beijing, grew out of the Cenozoic Research Laboratory in 1929 and is its own institution under the Chinese Academy of Sciences. Its staff have increasingly worked internationally, participating in the China-Canada Dinosaur Project from 1986 to 1991 and authoring or coauthoring forty-five ''Nature'' and ''Science'' articles from 1999 to 2005. Notable paleontologists who have been affiliated with the IVPP include Yang Zhongjian (also known as C. C. Young), Dong Zhiming, Meemann Chang and Zhao Xijin Zhao Xijin (赵喜进; born c. 1935 died July 21, 2012) was a Chinese paleontologist notable for having named numerous d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eubrachythoraci
Eubrachythoraci is an extinct clade of arthrodire placoderms within the suborder Brachythoraci, armored fish most diverse during the Devonian. Most are considered to be pelagic (open ocean) long-distance swimmers, leading to their widespread distribution beginning from at least the Middle Devonian period. Phylogeny Brachythoraci is divided into the large derived clade Eubrachythoraci and several basal groups: Buchanosteoidea, Homosteidae, and Holonematidae. (Although Holonematidae's membership in Brachythoraci is disputed.) Eubrachythoraci is then further divided into the sub-clades Coccosteomorphi and Pachyosteomorphi, the latter of which can be further sub-divided into Aspinothoracidi and Dunkleosteoidea, as shown in the 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 ... [...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] |
Zoological Journal Of The Linnean Society
The ''Zoological Journal of the Linnean Society'' is a monthly peer-reviewed scientific journal covering zoology published by Oxford University Press on behalf of the Linnean Society. The editor-in-chief is Maarten Christenhusz (Linnean Society). It was established in 1856 as the ''Journal of the Proceedings of the Linnean Society of London. Zoology'' and renamed ''Journal of the Linnean Society of London, Zoology'' in 1866. It obtained its current title in 1969. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 3.286. References External links * Zoology journals Linnean Society of London Monthly journals Academic journa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastmanosteus
''Eastmanosteus'' ("Eastman's bone") is a fossil genus of dunkleosteid placoderms. It was closely related to the giant ''Dunkleosteus'', but differed from that genus in size, in possessing a distinctive tuberculated bone ornament, a differently shaped nuchal plate and a more zig-zagging course of the sutures of the skull roof.http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/200812/W020090813371138329343.pdf Species of ''Eastmanosteus'' had powerful jaws with sharp cutting edges and were likely active predators. Fossils have been found in many parts of the world in marine sediments dating from the Middle to Late Devonian. They were medium-to-large fish, with specimens ''E. pustulosus'' and ''E. licharevi'' approaching a total length of 3 metres. Complete exoskeletons with soft-tissue traces of ''E. calliaspis'' from Australia make this one of the best known dunkleosteids. Phylogeny ''Eastmanosteus'' and its relative ''Dunkleosteus'' belong to the family Dunkleosteidae. The phylogeny of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastmanosteus Calliaspis
''Eastmanosteus'' ("Eastman's bone") is a fossil genus of dunkleosteid placoderms. It was closely related to the giant ''Dunkleosteus'', but differed from that genus in size, in possessing a distinctive tuberculated bone ornament, a differently shaped nuchal plate and a more zig-zagging course of the sutures of the skull roof.http://www.ivpp.cas.cn/cbw/gjzdwxb/xbwzxz/200812/W020090813371138329343.pdf Species of ''Eastmanosteus'' had powerful jaws with sharp cutting edges and were likely active predators. Fossils have been found in many parts of the world in marine sediments dating from the Middle to Late Devonian. They were medium-to-large fish, with specimens ''E. pustulosus'' and ''E. licharevi'' approaching a total length of 3 metres. Complete exoskeletons with soft-tissue traces of ''E. calliaspis'' from Australia make this one of the best known dunkleosteids. Phylogeny ''Eastmanosteus'' and its relative ''Dunkleosteus'' belong to the family Dunkleosteidae. The phylogeny of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gogo Reef
The Gogo Formation in the Kimberley region of Western Australia is a Lagerstätte that exhibits exceptional preservation of a Devonian reef community. The formation is named after Gogo Station, a cattle station where outcrops appear and fossils are often collected from, as is nearby Fossil Downs Station. History The reef, which now stands up abruptly in the western Australian desert (as the Windjana Limestone), was first identified in 1940 by paleontologist Curt Teichert, who discovered the first fossil fish from the region. Sedimentology Unweathered sections of the Gogo Formation are made of siltstone, shale and calcarenite with numerous limestone concretions. These concretions are resistant to weathering, producing extensive nodule fields on the ground in areas where the surrounding rock has eroded away. The Gogo sediments represent deep, hypoxic seafloor deposits in the vicinity of a large tropical reef composed primarily of algae and stromatoporoids during the Frasni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunkleosteidae
Dunkleosteidae is an extinct family of arthrodire placoderms that lived during the Devonian period. The gigantic apex predator ''Dunkleosteus terrelli'' is the best known member of this group. Phylogeny While members of Dunkleosteidae were previously thought to be close relatives of the genus ''Dinichthys'' (when they were not synonymized as each other) and grouped together in the family Dinichthyidae, more recent phylogenetic studies have shown that the two taxa represent two very distinct clades within Arthrodira. Dunkleosteidae was then established as the sister taxon to the family Panxiosteidae, which together comprised the superfamily Dunkleosteoidea (one of the three major clades of Eubrachythoraci). Dunkleosteidae was thus cladistically defined as including the type genus ''Dunkleosteus'' and all other genera in Dunkleosteoidea more closely related to ''Dunkleosteus'' than to '' Panxiosteus''. The phylogeny of Dunkleosteidae from the 2013 Zhu & Zhu study is shown in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eubrachythoraci
Eubrachythoraci is an extinct clade of arthrodire placoderms within the suborder Brachythoraci, armored fish most diverse during the Devonian. Most are considered to be pelagic (open ocean) long-distance swimmers, leading to their widespread distribution beginning from at least the Middle Devonian period. Phylogeny Brachythoraci is divided into the large derived clade Eubrachythoraci and several basal groups: Buchanosteoidea, Homosteidae, and Holonematidae. (Although Holonematidae's membership in Brachythoraci is disputed.) Eubrachythoraci is then further divided into the sub-clades Coccosteomorphi and Pachyosteomorphi, the latter of which can be further sub-divided into Aspinothoracidi and Dunkleosteoidea, as shown in the 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiangyousteus
''Kiangyousteus'' is an extinct monotypic genus of dunkleosteid from the Middle Devonian: Givetian aged Guanwu Formation in the Sichuan province of south-western China. The type species, ''Kiangyousteus yohii'', was the first known arthrodire from Asia. Etymology ''Kiangyousteus'' is named after Jiangyou (formerly ‘Kiangyou’) district of Sichuan Province, the location where the fossils were found in 1953 by Professor S. H. Yoh of Peking University. Phylogeny ''Kiangyousteus'' belongs to the family Dunkleosteidae. The phylogeny of ''Kiangyousteus'' can be shown in the cladogram below: Alternatively, the subsequent 2016 Zhu ''et al.'' study using a larger morphological dataset recovered Panxiosteidae well outside of Dunkleosteoidea, leaving the status of Dunkleosteidae Dunkleosteidae is an extinct family of arthrodire placoderms that lived during the Devonian period. The gigantic apex predator ''Dunkleosteus terrelli'' is the best known member of this group. Phylogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transitional Form
A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors. In 1859, when Charles Darwin's ''On the Origin of Species ''On the Origin of Species'' (or, more completely, ''On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
