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Venom Clade
Toxicofera (Greek for "those who bear toxins") is a proposed clade of scaled reptiles (squamates) that includes the Serpentes (snakes), Anguimorpha (monitor lizards, gila monster, and alligator lizards) and Iguania (iguanas, agamas, and chameleons). Toxicofera contains about 4,600 species, (nearly 60%) of extant Squamata. It encompasses all venomous reptile species, as well as numerous related non-venomous species. There is little morphological evidence to support this grouping, however it has been recovered by all molecular analyses as of 2012. The oldest known toxicoferan is ''Cryptovaranoides'', an anguimorph from the Late Triassic of England. Cladistics Toxicofera combines the following groups from traditional classification: * Suborder Serpentes (snakes) * Suborder Iguania (iguanas, agamid lizards, chameleons, etc.) * Infraorder Anguimorpha, consisting of: ** Family Varanidae (monitor lizards) ** Family Anguidae ( alligator lizards, glass lizards, etc.) ** Family Helo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rattlesnake
Rattlesnakes are venomous snakes that form the genera ''Crotalus'' and ''Sistrurus'' of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents. Rattlesnakes receive their name from the rattle located at the end of their tails, which makes a loud rattling noise when vibrated that deters predators or serves as a warning to passers-by. Rattlesnakes are the leading contributor to snakebite injuries in North America, but rarely bite unless provoked or threatened; if treated promptly, the bites are seldom fatal. The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from British Columbia through Ontario in southern Canada, to central Argentina. The largest rattlesnake, the eastern diamondback, can measure up to in length. Rattlesnakes are preyed upon by hawks, weasels, king snakes, and a variety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamata
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest order of reptiles, comprising lizards, snakes, and amphisbaenians (worm lizards), which are collectively known as squamates or scaled reptiles. With over 10,900 species, it is also the second-largest order of extant (living) vertebrates, after the perciform fish. Members of the order are distinguished by their skins, which bear horny scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very wide to accommodate comparatively large prey. Squamata is the most variably sized order of reptiles, ranging from the dwarf gecko (''Sphaerodactylus ariasae'') to the Reticulated python (''Malayopython reticulatus'') and the now-extinct mosasaurs, which reached lengths over . Among other reptiles, squamates are most close ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanidae
The Varanidae are a family of lizards in the superfamily Varanoidea within the Anguimorpha group. The family, a group of carnivorous and frugivorous lizards, includes the living genus '' Varanus'' and a number of extinct genera more closely related to ''Varanus'' than to the earless monitor lizard (''Lanthanotus''). ''Varanus'' includes the Komodo dragon (the largest living lizard), crocodile monitor, savannah monitor, the goannas of Australia and Southeast Asia, and various other species with a similarly distinctive appearance. Their closest living relatives are the earless monitor lizard and chinese crocodile lizard. The oldest members of the family are known from the Late Cretaceous of Mongolia. Taxonomy The Varanidae were defined (using morphological characteristics) by Estes, de Queiroz and Gauthier (1988) as the clade containing the most recent common ancestor of ''Lanthanotus'' and ''Varanus'' and all of its descendants. A similar definition was formulated by Conrad ''et al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agamid
Agamidae is a family of over 300 species of iguanian lizards indigenous to Africa, Asia, Australia, and a few in Southern Europe. Many species are commonly called dragons or dragon lizards. Overview Phylogenetically, they may be sister to the Iguanidae, and have a similar appearance. Agamids usually have well-developed, strong legs. Their tails cannot be shed and regenerated like those of geckos (and several other families such as skinks), though a certain amount of regeneration is observed in some. Many agamid species are capable of limited change of their colours to regulate their body temperature. In some species, males are more brightly coloured than females, and colours play a part in signaling and reproductive behaviours. Although agamids generally inhabit warm environments, ranging from hot deserts to tropical rainforests, at least one species, the mountain dragon, is found in cooler regions. They are particularly diverse in Australia. This group of lizards includes som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentes
Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more joints than their lizard ancestors, enabling them to swallow prey much larger than their heads (cranial kinesis). To accommodate their narrow bodies, snakes' paired organs (such as kidneys) appear one in front of the other instead of side by side, and most have only one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have evolved elongate bodies without limbs or with greatly reduced limbs about twenty-five times independently via convergent evolution, leading to many lineages of legless lizards. These resemble snakes, but several common groups of legless lizards have eyelids and external ears, which snakes lack, although this rule is not universal (see Amphisbaenia, Dibamida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Classification
Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. Among other things, a taxonomy can be used to organize and index knowledge (stored as documents, articles, videos, etc.), such as in the form of a library classification system, or a search engine taxonomy, so that users can more easily find the information they are searching for. Many taxonomies are hierarchies (and thus, have an intrinsic tree structure), but not all are. Originally, taxonomy referred only to the categorisation of organisms or a particular categorisation of organisms. In a wider, more general sense, it may refer to a categorisation of things or concepts, as well as to the principles underlying such a categorisation. Taxonomy organizes taxonomic units known as "taxa" (singular "taxon")." Taxonomy is different from m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science Advances
''Science Advances'' is a peer-reviewed multidisciplinary open-access scientific journal established in early 2015 and published by the American Association for the Advancement of Science. The journal's scope includes all areas of science, including life sciences, physical sciences, social sciences Social science is one of the branches of science, devoted to the study of societies and the relationships among individuals within those societies. The term was formerly used to refer to the field of sociology, the original "science of so ..., computer sciences, and environmental sciences. History The journal was announced in February 2014, and the first articles were published in early 2015. In 2019, ''Science Advances'' surpassed Science (journal), ''Science magazine'' in the number of monthly submissions, becoming the largest member in the Science family of journals. It is the only member of that family where all papers are gold open access. Editorial structure Editori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptovaranoides
''Cryptovaranoides'' ("hidden lizard-like animal") is an extinct genus of lizard from the Late Triassic of England. It contains a single species, ''Cryptovaranoides microlanius''. It is represented by a holotype partial skeleton as well as referred isolated bones from Rhaetian-aged fissure fill-deposits in Cromhall Quarry, near Tortworth, Gloucestershire preserved alongside the common fossil rhynchocephalian ''Clevosaurus''. The type specimen had been collected in 1953, but was only described as a distinct taxon in 2022. Several traits such as braincase, neck vertebrae, skull architecture, and teeth arrangement support ''Cryptovaranoides''' classification as a squamate. ''Cryptovaranoides'' marks the earliest known occurrence of a crown group squamate, with previous fossils known only as early as the Middle Jurassic; the discovery of ''Cryptovaranoides'' pushes back the estimated origin of modern squamates by 35 million years. A phylogenetic analysis placed ''Cryptovaranoides'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biology Letters
''Biology Letters'' is a peer-reviewed, biological, scientific journal published by the Royal Society. It focuses on the rapid publication of short high quality research articles, reviews and opinion pieces across the biological sciences. ''Biology Letters'' has an average turnaround time of twenty four days from submission to a first decision. The editor-in-chief is Professor David Beerling FRS (University of Sheffield) who is supported by an international Editorial Board of practising scientists. Contents and themes As well as the conventional, short research articles, ''Biology Letters'' has recently published Special Features and Mini Series. While Special Features are a collection of up to 20 articles on a specific theme and published across multiple issues, Mini Series include up to six articles that are published in one issue. Examples of topics in these formats include ocean acidification, fossils, extinction, enhanced rock weathering and the evolutionary ecology of sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BMC Evolutionary Biology
''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology. It was established in 2001 and is part of a series of BMC journals published by BioMed Central. 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 3.260. References External links * BioMed Central academic journals Creative Commons Attribution-licensed journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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