22-615: The Cryptobranchidae (commonly known as giant salamanders ) are a family of large salamanders that are fully aquatic . The family includes some of the largest living amphibians . They are native to China, Japan, and the eastern United States. Giant salamanders constitute one of two living families—the other being the Asiatic salamanders belonging to the family Hynobiidae—within the Cryptobranchoidea , one of two main divisions of living salamanders. The largest species are in
44-566: A suborder of salamanders found in Asia, European Russia, and the United States. They are known as primitive salamanders , in contrast to Salamandroidea , the advanced salamanders . It has two living subdivisions, Cryptobranchidae ( Asian giant salamanders and hellbenders ), and Hynobiidae , commonly known as Asian salamanders. Giant salamanders are obligate paedomorphs with partial metamorphosis, but Asiatic salamander goes through
66-557: A synonym of the former. Family (taxonomy) Family ( Latin : familia , pl. : familiae ) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to
88-456: A fossil as Homo diluvii testis ( Latin : Evidence of a diluvian human), believing it to be the remains of a human being who drowned in the biblical flood . The Teylers Museum in Haarlem , Netherlands , bought the fossil in 1802, where it is still exhibited. In 1812, the fossil was examined by Georges Cuvier , who recognized that it was not human. After being identified as a salamander, it
110-769: A full metamorphosis. The only known exceptions are the Longdong stream salamander , which has been documented as facultatively neotenic, and the Ezo salamander , where a now assumed extinct population from Lake Kuttarush in Hokkaido had neotenic traits like gills in adults. The oldest members of the group are known from the Middle Jurassic ( Bathonian ) aged Yanliao Biota of China. This suborder contains only two families at present. All other members are extinct and are only known as fossils. This salamander article
132-452: A group rather than individually. Scientists at Hiroshima City Asa Zoological Park in Japan have recently discovered the male salamander will spawn with more than one female in his den. Only large males can occupy and guard a den. They guard the den against other males and sexually inactive females. Those that are sexually active are welcomed. On occasion, the male "den master" will also allow
154-554: A lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching a consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called
176-516: A second male (smaller male salamanders, named "satellite males", who do not have their own den) into the den; the reason for this is unclear. Extant species in the family Cryptobranchidae are the modern-day members of a lineage that extends back tens of millions of years. The oldest known fossils of cryptobranchoids are known from the Middle Jurassic of China. Chunerpeton from the Middle Jurassic of China has been suggested to represent
198-424: Is generally used just for short distance-escapes to hiding places. The body is stout with large folds of skin along the flanks and a heavy, laterally compressed tail. These folds help increase the animals' surface area, allowing them to absorb more oxygen from the water as the adults lacks gills and have poorly developed lungs. Like in the majority of salamander species, there are four toes on the fore limbs and five on
220-462: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Cryptobranchoidea The Cryptobranchoidea are
242-634: The Paleocene . As the fossil record for the Cryptobranchidae shows an Asian origin for the family, how these salamanders made it to the eastern US has been a point of scientific interest. Research has indicated a dispersal via land bridge , with waves of adaptive radiation seeming to have swept the Americas from north to south. In 1726, the Swiss physician Johann Jakob Scheuchzer described
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#1732794046512264-617: The eastern United States and is the only member of the genus Cryptobranchus . The family name is from the Ancient Greek krypto ("hidden"), and branch ("gill"), which refer to how the members absorb oxygen through capillaries of their side-frills, which function as gills. Clade Pancryptobrancha (Cryptobranchidae + Ukrainurus ) The following phylogeny is based on Vasilyan et al . (2013): † Ukrainurus Cryptobranchus † Aviturus † Zaissanurus Andrias The well-represented Cretaceous Eoscapherpeton
286-542: The family Juglandaceae , but that family is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to
308-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and
330-420: The genus Andrias , native to east Asia . The South China giant salamander ( Andrias sligoi ), can reach a length of 1.8 m (5.9 ft). The Japanese giant salamander ( Andrias japonicus ) reaches up to 1.44 m (4.7 ft) in length, feeds at night on fish and crustaceans , and has been known to live for more than 50 years in captivity. The hellbender ( Cryptobranchus alleganiensis ) inhabits
352-840: The hind limbs. They have paedomorphic traits, meaning their metamorphosis from the larval stage is incomplete, so they lack eyelids and the adults retain gill slits (open in the hellbender, closed in Andrias). Eyes are small and the eyesight bad. In Japan, their natural habitats are threatened by dam-building. Ramps and staircases have been added to some dams to allow them to move upstream to areas where they spawn. A Japanese giant salamander lived for 52 years in captivity. The Chinese giant salamander eats aquatic insects, fish, frogs, crabs, and shrimp. They hunt mainly at night. As they have poor eyesight, they use sensory nodes on their heads and bodies to detect minute changes in water pressure, enabling them to find their prey. During mating season,
374-476: The oldest known cryptobranchid. However, some studies have found it to be a more basal cryptobranchoid not more closely related to Cryptobranchidae than to Hynobiidae . The next oldest cryptobranchid is Eoscapherpeton , known from numerous Late Cretaceous deposits in Central Asia, which is suggested to represent a stem-group to modern cryptobranchids. Modern crown group representatives appear during
396-491: The salamanders travel upstream, where the female lays two strings of over 200 eggs each. Lacking the stereotypical courtship behaviors found in other species, the male fertilizes the eggs externally by releasing his sperm onto them, and then guards them for at least three months, until they hatch. Tail fanning also occurs in order to increase the oxygen supply for the eggs. At this point, the larvae live off their noticeable stored fat until ready to hunt. Once ready, they hunt as
418-575: The seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted
440-549: The use of this term solely within the book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,
462-434: Was not phylogenetically placed. The enigmatic " Cryptobranchus " saskatchewanensis of Paleocene Canada may actually represent a stem-cryptobranchid. Cryptobranchids are large and predominantly nocturnal salamanders that can reach a length of 1.8 m (5.9 ft), though most are considerably smaller today. Despite being aquatic, they are poor swimmers and mostly just walk on the bottom. Swimming by undulatory locomotion
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#1732794046512484-418: Was renamed Salamandra scheuchzeri by Holl in 1831. The genus Andrias was coined six years later by Tschudi . In doing so, both the genus, Andrias (which means "image of man"), and the specific name , scheuchzeri , ended up honouring Scheuchzer and his beliefs. It and the extant A. davidianus cannot be mutually distinguished, and the latter, only described in 1871, is therefore sometimes considered
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