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Laterata
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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squamate
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 closely ... [...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 speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia although some lizards are more closely related to these two excluded groups 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 such as the forest-dwelling '' Draco'' lizards are able to glide. They are often 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 being sit-and-wait predators; many smaller species eat insects, while the Komodo eats mamma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selandian First Appearances
The Selandian is a stage in the Paleocene. It spans the time between . It is preceded by the Danian and followed by the Thanetian. Sometimes the Paleocene is subdivided in subepochs, in which the Selandian forms the "middle Paleocene". Stratigraphic definition The Selandian was introduced in scientific literature by Danish geologist Alfred Rosenkrantz in 1924. It is named after the Danish island of Zealand (Danish: ''Sjælland'') given its prevalence there.Selandien The base of the Selandian is close to the boundary between |
Vertebrate Superfamilies
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described. Vertebrates comprise such groups as the following: * jawless fish, which include hagfish and lampreys * jawed vertebrates, which include: ** cartilaginous fish (sharks, rays, and ratfish) ** bony vertebrates, which include: *** ray-fins (the majority of living bony fish) *** lobe-fins, which include: **** coelacanths and lungfish **** tetrapods (limbed vertebrates) Extant vertebrates range in size from the frog species ''Paedophryne amauensis'', at as little as , to the blue whale, at up to . Vertebrates make up less than five percent of all described animal species; the rest are invertebrates, which lack vertebral columns. The vertebrates traditionally include the hagfish, which do not h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berriasian
In the geological timescale, the Berriasian is an age/ stage of the Early/Lower Cretaceous. It is the oldest subdivision in the entire Cretaceous. It has been taken to span the time between 145.0 ± 4.0 Ma and 139.8 ± 3.0 Ma (million years ago). The Berriasian succeeds the Tithonian (part of the Jurassic) and precedes the Valanginian. Stratigraphic definition The Berriasian Stage was introduced in scientific literature by Henri Coquand in 1869. It is named after the village of Berrias in the Ardèche department of France. The largely non-marine English Purbeck Formation is in part of Berriasian age.In fact, the first rocks to be described of this age were the beds of the English Purbeck Formation, named as the Purbeckian by Alexandre Brongniart in 1829 following description by Henry De la Beche, William Buckland, Thomas Webster and William Henry Fitton. The base of the Berriasian, which is also the base of the Cretaceous System, has traditionally been placed at the fir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicofera
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.) ** Famil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skink
Skinks are lizards belonging to the family Scincidae, a family in the infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one of the most diverse families of lizards. Skinks are characterized by their smaller legs in comparison to typical lizards and are found in different habitats except arctic and subarctic regions. Description Skinks look like lizards of the family Lacertidae (sometimes called ''true lizards''), but most species of skinks have no pronounced neck and relatively small legs. Several genera (e.g., '' Typhlosaurus'') have no limbs at all. This is not true for all skinks, however, as some species such as the red-eyed crocodile skink have a head that is very distinguished from the body. These lizards also have legs that are relatively small proportional to their body size. Skinks' skulls are covered by substantial bony scales, usually matching up in shape and size, while overlapping. Other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Campanian
The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian. The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks. Etymology The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrop near the village of Aubeterre-sur-Dronne in the same region. Definition The base of the Campanian Stage is defined as a place in the stratigraphic col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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