|
Living Fossil
A living fossil is a Deprecation, deprecated term for an extant taxon that phenotypically resembles related species known only from the fossil record. To be considered a living fossil, the fossil species must be old relative to the time of origin of the extant clade. Living fossils commonly are of species-poor lineages, but they need not be. While the body plan of a living fossil remains superficially similar, it is never the same species as the remote relatives it resembles, because genetic drift would inevitably change its chromosomal structure. Living fossils exhibit punctuated equilibrium, stasis (also called "bradytely") over geologically long time scales. Popular literature may wrongly claim that a "living fossil" has undergone no significant evolution since fossil times, with practically no molecular evolution or Morphology (biology), morphological changes. Scientific investigations have repeatedly discredited such claims. The minimal superficial changes to living foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelacanth CAS 1
Coelacanths ( ) are an ancient group of Sarcopterygii, lobe-finned fish (Sarcopterygii) in the Class (biology), class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, birds and mammals) than to Actinopterygii, ray-finned fish. The name coelacanth originates from the Permian genus ''Coelacanthus'', which was the first scientifically named genus of coelacanths (in 1839), becoming the type genus of Coelacanthiformes as other species were discovered and named. Well-represented in freshwater and marine Geological formation, deposits from as early as the Devonian period (more than 410million years ago), they were thought to have become extinct in the Late Cretaceous, around Cretaceous–Paleogene extinction event, 66million years ago. The first living species, ''Latimeria chalumnae'', the West Indian Ocean coelacanth, was Species description, described from specimens Fishing, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lazarus Taxon
In paleontology, a Lazarus taxon (plural ''taxa'') is a taxon that disappears for one or more periods from the fossil record, only to appear again either in later fossil records, or as actual living organisms, and often in isolated, obscure, or otherwise very specialized habitats. Likewise in conservation biology and ecology, it can refer to species or populations that were mistakenly thought to be extinct, and are rediscovered to be still living. The term Lazarus taxon was coined by Karl W. Flessa and David Jablonski in 1983 and was then expanded by Jablonski in 1986. Paul Wignall and Michael Benton defined Lazarus taxa as, "At times of biotic crisis many taxa go extinct, but others only temporarily disappeared from the fossil record, often for intervals measured in millions of years, before reappearing unchanged". Earlier work also supports the concept though without using the name Lazarus taxon, like work by Christopher R. C. Paul. The term refers to the story in the Christ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eomeropidae
Eomeropidae is a family (biology), family of aberrant, flattened scorpionflies represented today by only a single living species, ''Notiothauma reedi'', known from the ''Nothofagus'' forests in southern Chile, while all other recognized genera in the family are known only as fossils, with the earliest definitive fossil known from Early Jurassic, Liassic-aged strata, and the youngest from Paleogene-aged strata.Archibald, S. Bruce, Alexandr P. Rasnitsyn, and Mikhail A. Akhmetiev. "Ecology and distribution of Cenozoic Eomeropidae (Mecoptera), and a new species of ''Eomerope'' Cockerell from the Early Eocene McAbee locality, British Columbia, Canada." Annals of the Entomological Society of America 98.4 (2005): 503-514. Ecology ''Notiothauma'' adults are thought to be Saprotrophic nutrition, saprophagous with a preference for carrion, having been observed feeding on dead chickens and rabbits, though in one experimental study they were also observed feeding on plant material. Genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mymarommatidae
The Mymarommatidae, sometimes referred to as false fairy wasps, are a very small family of microscopic parasitic wasps. Only about half of the known species are living taxa (the others are fossils), but they are found worldwide.Gibson, G.A.P.; Read, J.; Huber, J.T. (2007Diversity, classification and higher relationships of Mymarommatoidea (Hymenoptera).'Journal of Hymenoptera Research'' 16: 51–146 Little is known about the biology of these insects, but because of their size, and simple ovipositors, entomologists assumed they were idiobiont parasitoids on the eggs of insects, similar to other extremely small parasitic wasps such as fairyflies. Psocoptera, long suspected as their hosts based on circumstantial evidence, was confirmed to be the hosts of at least some mymarommatids in 2022, after specimens of ''Mymaromma menehune'' were observed emerging from the eggs of a member of the pscopteran family Lepidopsocidae.Honsberger DN, Huber JT, Wright MG (2022) A new ''Mymaromma' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glypheoidea
The Glypheoidea (containing the glypheoid lobsters), is a group of lobster-like Decapoda, decapod crustaceans which forms an important part of fossil faunas, such as the Solnhofen limestone. These fossils included taxa such as ''Glyphea'' (from which the group takes its name), and ''Mecochirus'', mostly with elongated (often semichelate) chelipeds. This group of decapods is a good example of a living fossil, or a lazarus taxon, since until their discovery in the 1970s, the group was considered to have become extinct in the Eocene. The superfamily (taxonomy), superfamily Glypheoidea comprises five family (biology), families. The two extant taxon, extant species, ''Neoglyphea inopinata'' and ''Laurentaeglyphea neocaledonica'', are both in the family Glypheidae. Prehistoric abundance The first animals attributable to the Glypheoidea appeared in the Permian, Permo-Triassic. They were abundant in the Jurassic, but declined from the Cretaceous to the Eocene. Extant taxa The Glypheoidea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dawn Redwood
''Metasequoia glyptostroboides'', the dawn redwood, is a fast-growing, endangered deciduous conifer. It is the sole living species of the genus ''Metasequoia'', one of three genera in the subfamily Sequoioideae of the family Cupressaceae. It now survives in the wild only in wet lower slopes and montane river and stream valleys in the border region of Hubei and Hunan provinces and Chongqing municipality in south-central China, notably in Lichuan county in Hubei. Although the shortest of the redwoods, it can grow to in height. In 1941, the genus ''Metasequoia'' was reported by paleobotanist as a widely distributed extinct genus based on fossils, before attracting considerable attention a few years later when small populations were found alive in central China. It is a well-known example of a living fossil species. Modern dawn redwood appears identical to its late Cretaceous ancestors. The tree faces considerable risks of extinction in its wild range due to deforestation; however ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelacanth
Coelacanths ( ) are an ancient group of lobe-finned fish (Sarcopterygii) in the class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, birds and mammals) than to ray-finned fish. The name coelacanth originates from the Permian genus '' Coelacanthus'', which was the first scientifically named genus of coelacanths (in 1839), becoming the type genus of Coelacanthiformes as other species were discovered and named. Well-represented in freshwater and marine deposits from as early as the Devonian period (more than 410million years ago), they were thought to have become extinct in the Late Cretaceous, around 66million years ago. The first living species, ''Latimeria chalumnae'', the West Indian Ocean coelacanth, was described from specimens fished off the coast of South Africa from 1938 onward; they are now also known to inhabit the seas around the Comoro Islands off the eas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genomics
Genomics is an interdisciplinary field of molecular biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes as well as its hierarchical, three-dimensional structural configuration. In contrast to genetics, which refers to the study of ''individual'' genes and their roles in inheritance, genomics aims at the collective characterization and quantification of ''all'' of an organism's genes, their interrelations and influence on the organism. Genes may direct the production of proteins with the assistance of enzymes and messenger molecules. In turn, proteins make up body structures such as organs and tissues as well as control chemical reactions and carry signals between cells. Genomics also involves the sequencing and analysis of genomes through uses of high throughput DNA sequencing and bioinformatics to assemble and analyze the function and structure of entire genomes. Advan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noncoding DNA
Non-coding DNA (ncDNA) sequences are components of an organism's DNA that do not encode protein sequences. Some non-coding DNA is transcribed into functional non-coding RNA molecules (e.g. transfer RNA, microRNA, piRNA, ribosomal RNA, and regulatory RNAs). Other functional regions of the non-coding DNA fraction include regulatory sequences that control gene expression; scaffold attachment regions; origins of DNA replication; centromeres; and telomeres. Some non-coding regions appear to be mostly nonfunctional, such as introns, pseudogenes, intergenic DNA, and fragments of transposons and viruses. Regions that are completely nonfunctional are called junk DNA. Fraction of non-coding genomic DNA In bacteria, the coding regions typically take up 88% of the genome. The remaining 12% does not encode proteins, but much of it still has biological function through genes where the RNA transcript is functional (non-coding genes) and regulatory sequences, which means that almost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ninth and longest geological period of the entire Phanerozoic. The name is derived from the Latin , 'chalk', which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation . The Cretaceous was a period with a relatively warm climate, resulting in high Sea level#Local and eustatic, eustatic sea levels that created numerous shallow Inland sea (geology), inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was largely ice-free, although there is some evidence of brief periods of glaciation during the cooler first half, and forests extended to the poles. Many of the dominant taxonomic gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latimeria
''Latimeria'' is a rare genus of fish which contains the two only living species of coelacanth. It includes two Extant taxon, extant species: the West Indian Ocean coelacanth (''Latimeria chalumnae'') and the Indonesian coelacanth (''Latimeria menadoensis''). They follow the oldest known living Lineage (evolution), lineage of Sarcopterygii (lobe-finned fish and tetrapods), which means they are more closely related to lungfish and tetrapods (amphibians, reptiles and mammals) than to the common ray-finned fishes and Chondrichthyes, cartilaginous fishes. They are found along the coastlines of the Indian Ocean and Indonesia. Since there are only two known species of coelacanth and both are threatened, it is one of the most endangered genera of animals in the world. The West Indian Ocean coelacanth is a critically endangered species. Biological characteristics Based on growth rings in the creatures' ear bones (otoliths), scientists infer that individual coelacanths may live as long ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coelacanthiformes
Coelacanths ( ) are an ancient group of Sarcopterygii, lobe-finned fish (Sarcopterygii) in the Class (biology), class Actinistia. As sarcopterygians, they are more closely related to lungfish and tetrapods (the terrestrial vertebrates including living amphibians, reptiles, birds and mammals) than to Actinopterygii, ray-finned fish. The name coelacanth originates from the Permian genus ''Coelacanthus'', which was the first scientifically named genus of coelacanths (in 1839), becoming the type genus of Coelacanthiformes as other species were discovered and named. Well-represented in freshwater and marine Geological formation, deposits from as early as the Devonian period (more than 410million years ago), they were thought to have become extinct in the Late Cretaceous, around Cretaceous–Paleogene extinction event, 66million years ago. The first living species, ''Latimeria chalumnae'', the West Indian Ocean coelacanth, was Species description, described from specimens Fishing, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
