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Alethinophidia
:''Common names: advanced snakes.'' The Alethinophidia are an infraorder of snakes that includes all snakes other than blind snakes and thread snakes. Snakes have long been grouped into families within Alethinophidia based on their morphology, especially that of their teeth. More modern phylogenetic hypotheses using genetic data support the recognition of 19 extant families (see below), although the taxonomy of alethinophidian snakes has long been debated, and ultimately the decision whether to assign a particular clade to a particular Linnaean rank (such as a superfamily, family, or subfamily) is arbitrary. Etymology The infraorder name Alethinophidia derives from the two Ancient Greek words (), meaning "truthful, genuine", and (), meaning "snake". Fossil record Fossils of alethinophidians were found in Cenomanian (Middle Cretaceous) sites of Wadi Milk Formation in Wadi Abu Hashim, Sudan. '' Coniophis'' presents the vertebral morphology similar to modern-day Anili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snakes
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 Amphisbae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amerophidia
The Amerophidia, also known as amerophidian snakes, are a superfamily of snakes that contains two families: Aniliidae (containing a single species, ''Anilius scytale The Aniliidae are a monotypic family created for the monotypic genus ''Anilius'' that contains the single species ''A. scytale''. Common names include American pipe snake and false coral snake. It is found in South America. This snake p ...'', the American red pipe snake or false coral snake) and the boa-like Tropidophiidae (containing two genera, ''Trachyboa'' (with two species) and ''Tropidophis'' (with either 17 or 33, depending on the authority)). The sister-group relationship between these two families is surprising and unintuitive when only morphology is considered, because Aniliidae more closely resemble the Asian pipe snakes in the families Cylindrophis, Cylindrophiidae and Anomochilus, Anomochilidae, whereas Tropidophiidae more closely resemble constricting, macrostomatan snakes such as Boidae an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afrophidia
Afrophidia is a clade of alethinophidian snakes comprising the groups Henophidia and Caenophidia, essentially making up the snakes people commonly associate with. The name refers to the deep split between Afrophidia and their sister taxon, Amerophidia, which originated in South American origin, and the afrophidians was recently hypothesized to represent a vicariant event of the breakup of Gondwanan South America and Africa. Unlike the scolecophidians and amerophidians, which have evolved to be small, the afrophidians have evolved many larger species. This is also the group in which venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a st ... has been developed in several lines of snakes. Below is a phylogeny of Afrophidia recovered from numerous phylogenetic work on snakes: Venomo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natrix Natrix
The grass snake (''Natrix natrix''), sometimes called the ringed snake or water snake, is a Eurasian non-venomous colubrid snake. It is often found near water and feeds almost exclusively on amphibians. Subspecies Many subspecies are recognized, including: ''Natrix natrix helvetica'' ( Lacépède, 1789) was formerly treated as a subspecies, but following genetic analysis it was recognised in August 2017 as a separate species, ''Natrix helvetica'', the barred grass snake. Four other subspecies were transferred from ''N. natrix'' to ''N. helvetica'', becoming ''N. helvetica cettii'', ''N. helvetica corsa'', ''N. helvetica lanzai'' and ''N. helvetica sicula''. Description The grass snake is typically dark green or brown in colour with a characteristic yellow or whitish collar behind the head, which explains the alternative name ringed snake. The colour may also range from grey to black, with darker colours being more prevalent in colder region ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeocene
The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Paleocene, the continents of the Northern Hemisphere were still connected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niger
) , official_languages = , languages_type = National languagesRépublique du Niger, "Loi n° 2001-037 du 31 décembre 2001 fixant les modalités de promotion et de développement des langues nationales." L'aménagement linguistique dans le monde (accessed 21 September 2016) , languages = , religion_ref = , religion_year = 2012 , religion = , demonym = Nigerien , capital = Niamey , coordinates = , largest_city = Niamey , government_type = Unitary state, Unitary Semi-presidential s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
