|
2017 In Paleoichthyology
This list of fossil fishes described in 2017 is a list of new taxa of jawless vertebrates, placoderms, acanthodians, fossil cartilaginous fishes, bony fishes and other fishes of every kind that are scheduled to be described during the year 2017, as well as other significant discoveries and events related to paleontology of fishes that are scheduled to occur in the year 2017. The list only includes taxa at the level of genus or species. Research * A study on the marine fish extinction rates during background and mass extinctions from the Permian through Early Jurassic, compared with extinction trajectories of marine invertebrates, is published by Vázquez & Clapham (2017). * A study on the ecological diversity and lifestyles of thelodonts as indicated by their squamation patterns is published by Ferrón & Botella (2017). * A study on the phylogenetic relationships of jawless fish assigned to Cyathaspididae and Pteraspidiformes is published by Randle & Sansom (2017). * A study ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the abs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornovichthys
''Cornovichthys'' is an extinct genus of jawless fish in the super class Anaspidomorphi Anaspidomorphi (anaspidomorphs) is an extinct superclass of jawless fish. According to the newer taxonomy based on the work of Nelson, Grande and Wilson 2016 and van der Laan 2018, the phylogeny of Anaspidomorphi looks like this: * Superclass � .... It is known from the Middle Devonian of Scotland. References External links Anaspidomorphi genera Fossil taxa described in 2001 {{paleo-jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Komi Republic
The Komi Republic (russian: Республика Коми; kv, Коми Республика), sometimes simply referred to as Komi, is a republic of Russia located in Eastern Europe. Its capital is the city of Syktyvkar. The population of the republic as of the 2010 Census was 901,189. History The Komi people first feature in the records of the Novgorod Republic in the 12th century, when East Slavic traders from Novgorod traveled to the Perm region in search of furs and animal hides. The Komi territories came under the influence of Muscovy in the late Middle Ages (late 15th to early 16th centuries). The site of Syktyvkar, settled from the 16th century, was known as Sysolskoye (Сысольскoe). In 1780, under Catherine the Great, it was renamed to Ust-Sysolsk (Усть-Сысольск) and used as a penal colony. Russians explored the Komi territory most extensively in the 19th and early 20th centuries, starting with the expedition led by Alexander von Keyserl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sosnogorsk Formation
Sosnogorsk (russian: Сосного́рск; kv, Сӧснагорт, ''Sösnagort'') is a town in the Komi Republic, Russia, located on the Izhma River. Population: History The settlement was first established in 1939 as a railway station. It was known as Izhma () until 1957. During the Soviet era, a corrective labor camp was located here. Gas giant Gazprom has a natural-gas condensate factory in the town. Administrative and municipal status Within the framework of administrative divisions, the town of Sosnogorsk is, together with two urban-type settlement administrative territories (comprising the urban-type settlements of Voyvozh and Nizhny Odes and three rural localities) and thirteen rural localities, incorporated as the town of republic significance of Sosnogorsk—an administrative unit with the status equal to that of the districts A district is a type of administrative division that, in some countries, is managed by the local government. Across the world, areas k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Famennian
The Famennian is the latter of two faunal stages in the Late Devonian Epoch. The most recent estimate for its duration estimates that it lasted from around 371.1 million years ago to 359.3 million years ago. An earlier 2012 estimate, still used by the International Commission on Stratigraphy, estimated that it lasted from million years ago to million years ago. It was preceded by the Frasnian stage and followed by the Tournaisian stage. Major events In the seas, a novel major group of ammonoid cephalopods called clymeniids appeared, underwent tremendous diversification and spread worldwide, then just as suddenly went extinct. The beginning of the Famennian is marked by the final stages of a major extinction event, the Kellwasser Event, which is the largest component of the Late Devonian Mass extinction. The end of the Famennian experiences a smaller but still quite severe extinction event, the Hangenberg Event. A brief episode of glaciation, possibly linked to the Han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bothriolepis
''Bothriolepis'' (from el, βόθρος , 'trench' and el, λεπίς 'scale') was a widespread, abundant and diverse genus of antiarch placoderms that lived during the Middle to Late Devonian period of the Paleozoic Era. Historically, ''Bothriolepis'' resided in an array of paleo-environments spread across every paleocontinent, including near shore marine and freshwater settings. Most species of ''Bothriolepis'' were characterized as relatively small, benthic, freshwater detritivores (organisms that obtain nutrients by consuming decomposing plant/animal material), averaging around in length. However, the largest species, ''B. rex'', had an estimated bodylength of . Although expansive with over 60 species found worldwide, comparatively ''Bothriolepis'' is not unusually more diverse than most modern bottom dwelling species around today. Classification ''Bothriolepis'' is a genus placed within the placoderm order Antiarchi. The earliest antiarch placoderms first appeared in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romundina
''Romundina'' is a small, heavily armored extinct genus of acanthothoracid placoderms which lived in shallow marine environments in the early Devonian (Lochkovian). The name ''Romundina'' honors Canadian geologist and paleontologist Dr. Rómundur (Raymond) Thorsteinsson of Calgary, Alberta, Canada. ''Romundina'' are believed to have lived on Earth between 400 and 419 million years ago. The closest known relative to ''Romundina'' is the acanthothoracid '' Radotina''. The type and only described species is ''R. stellina''. The first specimen of ''Romundina'' was originally discovered by Swedish paleontologist Tor Ørvig in 1975 on Prince of Wales Island (Nunavut) in a formation that geologically dates back to the Gedinnian. Only one known species of ''Romundina'' has been discovered which was named ''Romundina stellina'' by Ørvig. The species name ''stellina'' refers to stellate (derived from Latin word stella meaning star) tubercles that the Placoderm has ornamenting its der ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraplesiobatis
''Paraplesiobatis heinrichsi'' is a lightly armored pseudopetalichthyid placoderm from the Hunsrückschiefer Lagerstätte of Early Devonian Germany. The type and only known specimen is an articulated, but very incomplete individual consisting of a large, incomplete, plate-covered head, and some of the vertebral column, with a total length of 10 centimeters. The specimen strongly resembles ''Pseudopetalichthys'' to the point that many experts suggest they may be of the same genus or species, though because the only specimens of both genera are so poorly preserved, talk of synonymizing the two can not begin (let alone continue) until more, better preserved specimens are found. References External links ''Pseudopetalichthys''at the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals, plants, and microorganisms. History The Paleobiology Database (PBDB) originated in the NCEAS-funded P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance ( shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyly
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic groups are typically characterised by shared derived characteristics (synapomorphies), which distinguish organisms in the clade from other organisms. An equivalent term is holophyly. The word "mono-phyly" means "one-tribe" in Greek. Monophyly is contrasted with paraphyly and polyphyly as shown in the second diagram. A ''paraphyletic group'' consists of all of the descendants of a common ancestor minus one or more monophyletic groups. A '' polyphyletic group'' is characterized by convergent features or habits of scientific interest (for example, night-active primates, fruit trees, aquatic insects). The features by which a polyphyletic group is differentiated from others are not inherited from a common ancestor. These definitions have take ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placodermi
Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally ' plate-skinned') is a class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked, depending on the species. Placoderms were among the first jawed fish; their jaws likely evolved from the first of their gill arches. Placoderms are thought to be paraphyletic, consisting of several distinct outgroups or sister taxa to all living jawed vertebrates, which originated among their ranks. In contrast, one 2016 analysis concluded that placodermi are likely monophyletic, though these analyses have been further dismissed with more transitional taxa between placoderms and modern gnathosthomes, solidifying their paraphyletic status. Placoderms were also the first fish to develop pelvic fins, the precursor to hindlimbs in tetrapods, as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnathostomata
Gnathostomata (; from Greek: (') "jaw" + (') "mouth") are the jawed vertebrates. Gnathostome diversity comprises roughly 60,000 species, which accounts for 99% of all living vertebrates, including humans. In addition to opposing jaws, living gnathostomes have true teeth (a characteristic which has subsequently been lost in some), paired appendages (pectoral and pelvic fins, arms, legs, wings, etc.), the elastomeric protein of elastin, and a horizontal semicircular canal of the inner ear, along with physiological and cellular anatomical characters such as the myelin sheaths of neurons, and an adaptive immune system that has the discrete lymphoid organs of spleen and thymus, and uses V(D)J recombination to create antigen recognition sites, rather than using genetic recombination in the variable lymphocyte receptor gene. It is now assumed that Gnathostomata evolved from ancestors that already possessed a pair of both pectoral and pelvic fins. Until recently these an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
