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Norellius
''Norellius'' is an extinct genus of scleroglossan lizard from the Early Cretaceous Öösh Formation of Mongolia. It is known from a well-preserved skull that was collected by an American Museum of Natural History expedition to Mongolia in 1923 and cataloged as AMNH FR 21444. After its initial cataloging, the specimen was not mentioned again in the scientific literature until 2004, when it was recognized as belonging to a potential early relative of modern groups of squamates such as gekkotans, amphisbaenians, dibamids, and snakes. AMNH FR 21444 was more fully described in a 2006 study that used high-resolution computed tomography to examine the skull and its braincase, and was described as a new genus and species, ''Norellius nyctisaurops'', in 2015. The genus name honors paleontologist Mark Norell. The 2006 study incorporated the specimen into a phylogenetic analysis and found it to be a basal member of an evolutionary grouping called Gekkonomorpha, a stem-based taxon that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eichstaettisaurus
''Eichstaettisaurus'' (meaning "Eichstätt lizard") is a genus of lizards from the Late Jurassic and Early Cretaceous of Germany, Spain, and Italy. With a flattened head, forward-oriented and partially symmetrical feet, and tall claws, ''Eichstaettisaurus'' bore many adaptations to a climbing lifestyle approaching those of geckoes. The type species, ''E. schroederi'', is among the oldest and most complete members of the Squamata, being known by one specimen originating from the Tithonian-aged Solnhofen Limestone of Germany. A second species, ''E. gouldi'', was described from another skeleton found in the Matese Mountains of Italy. Despite being very similar to ''E. schroederi'', it lived much later, during the Albian stage. Fossils of both species show exceptional preservation due to deposition in low-oxygen marine environments. Initially named as a species of the genus '' Ardeosaurus'' by Ferdinand Broili in 1938, ''E. schroederi'' has had a convoluted taxonomic history. It w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gekkonomorpha
Gekkonomorpha is a clade of lizards that includes geckos and their closest relatives. Although it was first named in 1900, Gekkonomorpha was not widely used as a formal taxon until it was given a phylogenetic definition in the 1990s. Under this definition, Gekkonomorpha is a stem-based taxon containing the node-based taxon Gekkota, the group that includes the last common ancestor of all living geckos and its descendants. The extent of Gekkonomorpha beyond gekkotans differs between studies. For example, Lee (1998) defined Gekkonomorpha in such a way that it included not only Gekkota but the legless amphisbaenian and dibamid lizards as well. The phylogenetic analysis of Conrad (2008), which did not support a close relationship between geckos and legless lizards, used Gekkonomorpha in a much more restrictive sense so that it included only Gekkota and a few extinct lizards more closely related to Gekkota than to any other living group of lizards (making them "stem" gekkotans). Some o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Öösh Formation
The Öösh Formation, also known as the Tevsh Formation is a geological formation of Lower Cretaceous strata in Mongolia. Dinosaur remains are among the fossils that have been recovered from the formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Early Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 563-570. . It overlies folded and metamorphosed basement strata of the Gobi region, and is capped by basalt. The succession is around 600 metres thick and consists of red claystones and sandstones, along with black thinly laminated shales. The claystones and sandstones were deposited as part of an alluvial fan system, while the shales were deposited in lakes present in the foot of the fan. Many of the fossils come from the "Cannonball beds", which comprise the lowest 60 metres of the unit and consist of green siltstone. Vertebrate paleofauna Dinosaurs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gekkota
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos are unique among lizards for their vocalisations, which differ from species to species. Most geckos in the family Gekkonidae use chirping or clicking sounds in their social interactions. Tokay geckos (''Gekko gecko'') are known for their loud mating calls, and some other species are capable of making hissing noises when alarmed or threatened. They are the most species-rich group of lizards, with about 1,500 different species worldwide. All geckos, except species in the family Eublepharidae lack eyelids; instead, the outer surface of the eyeball has a transparent membrane, the cornea. They have a fixed lens within each iris that enlarges in darkness to let in more light. Since they cannot blink, species without eyelids generally lick t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gekkota
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos are unique among lizards for their vocalisations, which differ from species to species. Most geckos in the family Gekkonidae use chirping or clicking sounds in their social interactions. Tokay geckos (''Gekko gecko'') are known for their loud mating calls, and some other species are capable of making hissing noises when alarmed or threatened. They are the most species-rich group of lizards, with about 1,500 different species worldwide. All geckos, except species in the family Eublepharidae lack eyelids; instead, the outer surface of the eyeball has a transparent membrane, the cornea. They have a fixed lens within each iris that enlarges in darkness to let in more light. Since they cannot blink, species without eyelids generally lick t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gecko
Geckos are small, mostly carnivorous lizards that have a wide distribution, found on every continent except Antarctica. Belonging to the infraorder Gekkota, geckos are found in warm climates throughout the world. They range from . Geckos are unique among lizards for their vocalisations, which differ from species to species. Most geckos in the family Gekkonidae use chirping or clicking sounds in their social interactions. Tokay geckos (''Gekko gecko'') are known for their loud mating calls, and some other species are capable of making hissing noises when alarmed or threatened. They are the most species-rich group of lizards, with about 1,500 different species worldwide. All geckos, except species in the family Eublepharidae lack eyelids; instead, the outer surface of the eyeball has a transparent membrane, the cornea. They have a fixed lens within each iris that enlarges in darkness to let in more light. Since they cannot blink, species without eyelids generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bavarisaurus
''Bavarisaurus'' ('Bavarian lizard') is an extinct genus of basal squamate found in the Solnhofen limestone near Bavaria, Germany.''Bavarisaurus'' at Fossilworks.org A skeleton found in the region of a '''', a small |
Scincogekkonomorpha
Scincogekkonomorpha is a clade (evolutionary grouping) of lizards that includes scleroglossans and all lizards more closely related to scleroglossans than to iguanians. These "stem" scleroglossans include extinct lizards from the Late Jurassic and Early Cretaceous such as ''Bavarisaurus'', ''Eichstaettisaurus'', '' Liushusaurus'', and '' Scandensia''. Scincogekkonomorpha was named in 1961 and is now occasionally used as a stem-based taxon in contrast to the node-based taxon Scleroglossa. According to phylogenies based on morphological characteristics, Scincogekkonomorpha is the sister taxon of Iguania and together they make up crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor ... Squamata, the smallest clade including all living snakes and lizards. References Tetr ... [...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 Iguanias are arboreal but there are several terrestrial groups. They usually have primitive fleshy, non-prehensile tongues, although the tongue is highly modified in chameleons. The group has a fossil record that extends back to the Early Jurassic (the oldest known member is '' Bha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hoyalacerta
''Hoyalacerta'' is an extinct genus of lizard known from the type species ''Hoyalacerta sanzi'', which is from the Early Cretaceous Las Hoyas fossil site in Spain. ''Hoyalacerta'' was named in 1999 and is considered either a member of the group Iguania or a stem squamate, meaning that it lies outside the squamate crown group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ... that includes all living lizards and snakes. ''Hoyalacerta'' is a small lizard with an elongated body and short limbs. It is thought to have spent most of its time on the ground. Several other lizards are also known from Las Hoyas, including '' Meyasaurus'' (thought to have lived near the water), '' Scandensia'' (thought to be a climber), and '' Jucaraseps'' (which, like ''Hoyalacerta'', probably lived on the g ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
