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Squamate
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it is also the second-largest order of Neontology, extant (living) vertebrates, after the Perciformes, perciform fish. Squamates are distinguished by their skins, which bear horny scale (zoology), scales or shields, and must periodically engage in molting. They also possess movable quadrate bones, making possible movement of the Maxilla, upper jaw relative to the neurocranium. This is particularly visible in snakes, which are able to open their mouths very widely to accommodate comparatively large prey. Squamates are the most variably sized living reptiles, ranging from the Sphaerodactylus ariasae, dwarf gecko (''Sphaerodactylus ariasae'') to the reticulated python (''Malayopython reticulatus''). The now-Extinction, extinct mosasaurs reached ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reptiles
Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocephalia. About 12,000 living species of reptiles are listed in the Reptile Database. The study of the traditional reptile orders, customarily in combination with the study of modern amphibians, is called herpetology. Reptiles have been subject to several conflicting Taxonomy, taxonomic definitions. In Linnaean taxonomy, reptiles are gathered together under the Class (biology), class Reptilia ( ), which corresponds to common usage. Modern Cladistics, cladistic taxonomy regards that group as Paraphyly, paraphyletic, since Genetics, genetic and Paleontology, paleontological evidence has determined that birds (class Aves), as members of Dinosauria, are more closely related to living crocodilians than to other reptiles, and are thus nested among re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosasauria
Mosasauria is a clade of aquatic and semiaquatic squamates that lived during the Cretaceous period. Fossils belonging to the group have been found in all continents around the world. Early mosasaurians like dolichosaurs were small long-bodied lizards that inhabited nearshore coastal and freshwater environments; the Late Cretaceous saw the rise of large marine forms, the mosasaurids, which are the clade's best-known members. The clade is defined as all descendants of the last common ancestor of the mosasaur '' Mosasaurus hoffmannii'' and dolichosaurs '' Dolichosaurus'', '' Coniasaurus'', and '' Adriosaurus suessi''. Its placement within the squamate tree is highly controversial. Two prominent hypotheses include the varanoid hypothesis, which holds that mosasaurians are most closely related to monitor lizards, and the pythonomorph hypothesis, which argues for a sister relationship with snakes. A third ophidiomorph hypothesis argues that snakes are members of the Mosasauria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicofera
Toxicofera (Latin for "toxin-bearers") is a proposed clade of squamata, scaled reptiles (squamates) that includes the snake, Serpentes (snakes), Anguimorpha (monitor lizards, Helodermatidae, beaded lizards, and alligator lizards) and Iguania (iguanas, Agama (lizard), agamas, and chameleons). Toxicofera contains about 4,600 species (nearly 60%) of extant taxon, extant Squamata. It encompasses all Venom (poison), 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. Cladistics Toxicofera combines the following groups from traditional Scientific classification, classification: * Suborder Serpentes (snakes) * Suborder Iguania (iguanas, agamid lizards, chameleons, etc.) * Suborder Anguimorpha, consisting of: ** Family Varanidae (monitor lizards) ** Family Lanthanotidae (earless monitor lizard) ** Family Anguidae (alligator lizard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidosauria
The Lepidosauria (, from Greek meaning ''scaled lizards'') is a Order (biology), superorder or Class (biology), subclass of reptiles, containing the orders Squamata and Rhynchocephalia. Squamata also includes Lizard, lizards and Snake, snakes. Squamata contains over 9,000 species, making it by far the most species-rich and diverse order of non-avian reptiles in the present day. Rhynchocephalia was a formerly widespread and diverse group of reptiles in the Mesozoic era, Mesozoic Era. However, it is represented by only one living species: the tuatara (''Sphenodon punctatus),'' a superficially lizard-like reptile native to New Zealand. Lepidosauria is a monophyletic group (i.e. a clade), containing all descendants of the Most recent common ancestor, last common ancestor of squamates and rhynchocephalians. Lepidosaurs can be distinguished from other reptiles via several traits, such as large Keratin, keratinous Scale (anatomy), scales which may overlap one another. Purely in the conte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snake
Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have skulls with several more joints than their lizard ancestors and relatives, 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 only have one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have independently evolved elongate bodies without limbs or with greatly reduced limbs at least twenty-five times 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, althoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentes
Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have skulls with several more joints than their lizard ancestors and relatives, 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 only have one functional lung. Some species retain a pelvic girdle with a pair of vestigial claws on either side of the cloaca. Lizards have independently evolved elongate bodies without limbs or with greatly reduced limbs at least twenty-five times 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchocephalia
Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a speciose group with high morphological and ecological diversity. The oldest record of the group is dated to the Middle Triassic around 238 to 240 million years ago, and they had achieved global distribution by the Early Jurassic. Most rhynchocephalians belong to the group Sphenodontia ('wedge-teeth'). Their closest living relatives are lizards and snakes in the order Squamata, with the two orders being grouped together in the superorder Lepidosauria. Rhynchocephalians are distinguished from squamates by a number of traits, including the retention of rib-like gastralia bones in the belly, as well as most rhynchocephalians having acrodont teeth that are fused to the crests of the jaws (the latter also found among a small number of modern lizard grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dibamidae
Dibamidae or blind skinks is a family of lizards characterized by their elongated cylindrical body and an apparent lack of limbs. Female dibamids are entirely limbless and the males retain small flap-like hind limbs, which they use to grip their partner during mating. They have a rigidly fused skull, lack pterygoid teeth and external ears. Their eyes are greatly reduced, and covered with a scale. They are small insectivorous lizards, with long, slender bodies, adapted for burrowing into the soil. They usually lay one egg with a hard, calcified shell, rather than the leathery shells typical of many other reptile groups. The family Dibamidae has two genera, '' Dibamus'' with 23 species native to Southeast Asia, Indonesia, the Philippines, and western New Guinea and the monotypic '' Anelytropsis'' native to Mexico. Recent phylogenetic analyses place the dibamids as the sister clade to all the other lizards and snakes or classify them as sharing a common ancestor with the infraord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anguimorpha
The Anguimorpha is a suborder of Squamata, squamates. The group was named by Fürbringer in 1900 to include all autarchoglossans closer to ''Varanus'' and ''Anguis'' than ''Scincus''. These lizards, along with iguanians and snakes, constitute the proposed "venom clade" Toxicofera of all venomous reptiles. Evolution The oldest widely accepted member of Anguimorpha is ''Dorsetisaurus'' from the Late Jurassic of Europe and North America. In 2022, the genus ''Cryptovaranoides'' was described from the latest Triassic (Rhaetian) of England. ''Cryptovaranoides'' was recovered in the study as a crown-group anguimorph, and therefore the oldest crown group-squamate, 35 million years older than any previously known crown-group squamate. However, a 2023 study found that ''Cryptovaranoides'' most likely represents an Archosauromorpha, archosauromorph that was only distantly related to squamates. Families Anguidae There are 9 genera found within the Anguidae family. They are characteriz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard
Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 species, ranging across all continents except Antarctica, as well as most Island#Oceanic islands, oceanic Archipelago, island chains. The grouping is Paraphyly, paraphyletic as some lizards are more closely related to snakes than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3-meter-long Komodo dragon. Most lizards are quadrupedal, running with a strong side-to-side motion. Some lineages (known as "legless lizards") have secondarily lost their legs, and have long snake-like bodies. Some lizards, such as the forest-dwelling ''Draco (genus), Draco'', are able to glide. They are often Territory (animal), territorial, the males fighting off other males and signalling, often with bright colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguania
Iguania is an infraorder of squamate reptiles that includes iguanas, chameleons, agamids, and New World lizards like anoles and phrynosomatids. Using morphological features as a guide to evolutionary relationships, the Iguania are believed to form the sister group to the remainder of the Squamata, which comprise nearly 11,000 named species, roughly 2000 of which are iguanians. However, molecular information has placed Iguania well within the Squamata as sister taxa to the Anguimorpha and closely related to snakes. The order has been under debate and revisions after being classified by Charles Lewis Camp in 1923 due to difficulties finding adequate synapomorphic morphological characteristics. Most iguanians are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. Today they are scattered occurring in Madagascar, the Fiji and Friendly Islands and Western Hemispher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacertoidea
The Lacertoidea is a group of squamate reptiles that includes the Lacertidae, Teiidae, Gymnophthalmidae, and Amphisbaenia. The finding from molecular phylogenetic studies that the burrowing Amphisbaenia were nested in a clade with the lizard forms led Vidal & Hedges (2005) to propose a new name for the group based on shared morphogical characters, Laterata, "referring to the presence of tile-like (squarish or quadrangular, and sometimes raised) scales that form the rings in Amphisbaenia, and are also present ventrally in Lacertiformata and Teiformata". Studies of anatomy have traditionally grouped the lacertoids with skinks; however, more recent studies focusing on DNA have placed them as a distinct group of lizards, more closely related to the venomous Toxicofera.Wiens, J. J., Hutter, C. R., Mulcahy, D. G., Noonan, B. P., Townsend, T. M., Sites, J. W., & Reeder, T. W. (2012). Resolving the phylogeny of lizards and snakes (Squamata) with extensive sampling of genes and species. Bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
