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Hoeckosaurus
''Hoeckosaurus'' is an extinct genus of lizard from the Oligocene of Mongolia. It contains a single species, ''H. mongoliensis''. The genus name commemorates Austrian paleontologist Gudrun Höck, who collected the type material. ''Hoeckosaurus'' was a member of the Dibamidae (a family of primitive legless squamates), and represents the only known fossil record of the Dibamidae, despite the presumed ancient origins of the group. Despite the close resemblance of the fossils to extant dibamids in the genera ''Dibamus'' and '' Anelytropsis'', some distinguishing features such as an open Meckelian groove suggests that ''Hoeckosaurus'' is basal to both. The remains of ''Hoeckosaurus'' consist of some jawbones, and were collected in 1995-1997 from the Valley of the Lakes in central Mongolia. The sediments they were collected from are thought to be Early Oligocene in age. Previous studies postulated the jaws as belonging to an arretosaurid (an extinct family of Asian iguanians) or ... [...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] |
Arretosauridae
The Arretosauridae are an extinct family of iguanian lizards from the Paleogene of east-central Asia. Long represented only by a single genus ('' Arretosaurus''), more recent studies indicate that they were far more diverse than previously assumed, with at least five different genera now known. Given their apparent diversity and abundance, they are thought to have been an important component of Paleogene Asian herpetofauna. Their exact taxonomic classification is debated; they are alternatively classified in either the Pleurodonta as a sister group to the North American Crotaphytidae (based on similar jaw features), or in the Acrodonta with the other Old World iguanians. The following genera are known: * †'' Arretosaurus'' Gilmore, 1943 * †'' Dornosaurus'' Alifanov 2012 * †'' Ergiliinsaurus'' Alifanov 2012 * †'' Hemishinisaurus'' Li, 1991 * †'' Khaichinguana'' Alifanov 2012 Fossils of the lizard '' Hoeckosaurus'' were previously thought to belong to arretosaurid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. Phylogeneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils Of Mongolia
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Though the fossil record is incomplete, numerous studies have demonstrated that there is enough information available to give a good understanding of the pattern of diversification of life on Earth. In addition, the record can predict and fill gaps such as the discovery of '' Tiktaalik'' in the arctic of Canada. Paleontology includes the study of fossils: their age, method of formation, and evolutionary significance. Specimens are sometimes considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years to 4.1 billion years old. Early edition, published online before print. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphisbaenia
Amphisbaenia (called amphisbaenians or worm lizards) is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. As many species have a pink body and scales arranged in rings, they have a superficial resemblance to earthworms. While the genus '' Bipes'' retains forelimbs, all other genera are limbless. Phylogenetic studies suggest that they are nested within Lacertoidea, closely related to the lizard family Lacertidae. Amphisbaenians are widely distributed, occurring in North America, Europe, Africa, South America, Western Asia and the Caribbean. Most species are less than long. Description 200px, left, Close-up of the head of'' Rhineura'' Despite a superficial resemblance to some primitive snakes, amphisbaenians have many unique features that distinguish them from other reptiles. Internally, their right lung is reduced in size to fit their narrow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iguanomorpha
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 Hemisphere. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rupelian
The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian Stage. Name The stage is named after the small river Rupel in Belgium, a tributary to the Scheldt. The Belgian Rupel Group derives its name from the same source. The name Rupelian was introduced in scientific literature by Belgian geologist André Hubert Dumont in 1850. The separation between the group (stratigraphy), group and the stage was made in the second half of the 20th century, when stratigraphers saw the need to distinguish between lithostratigraphy, lithostratigraphic and chronostratigraphy, chronostratigraphic names. Stratigraphic definition The base of the Rupelian Stage (which is also the base of the Oligocene Series) is at the extinction of the foram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valley Of The Lakes
The Valley of the Lakes () is an intermontane depression located in southwestern Mongolia, separating the Khangai and Govi-Altai mountains. The valley stretches 500 km long, has a width of approximately 100 km, and is located at altitudes ranging between 1000 and 1400 meters above sea level. The topography is dominated by sandy and rocky plains, with solonchak and takir soils present. Along the valley floor lies a chain of large and small saline lakes, which are generally shallow, with a saucer-shaped depth profile. The largest of these lakes are Böön Tsagaan Lake and Orog Lake. Water levels vary considerably in size both seasonally and from year to year, and some lakes may dry out completely in certain years. They all receive their inflow from rivers which rise in the Khangai Mountains, and no permanent inflow comes from the Gobi-Altai. Barchan sand dunes are located on the valley's margins. The region near the Govi-Altai is a seismically active zone and is where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexican Blind Lizard
The Mexican blind lizard (''Anelytropsis papillosus'') is a species of legless lizard in the family Dibamidae, and the only species in the genus ''Anelytropsis''. It is endemic to Mexico. They look like Amphisbaenia, but are in fact, only distantly related. Etymology Although early authors did not discuss the etymology, the generic name, ''Anelytropsis'', is presumed to be based on the Greek words: ''ana'' = up opon; ''elytron'' = shield; ''ops'' = eye, in reference to the eyes which are concealed by ocular scales. The trivial name or specific epithet, ''papillosus'', is Latin and refers to the minute papillae present on the scales in the anterior areas of the mouth and nose (rostral scale, first labial scale, and Loreal (scale), loreal).Campbell, Howard W. 1974. ''Catalogue of American Amphibians and Reptiles: Anelytropsis, A. papillosus.'' Society for the Study of Amphibians and Reptiles. 156:1–2. Description The Mexican blind lizard is a limbless lizard, adapted for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meckelian Groove
The Meckelian groove (or Meckel's groove, Meckelian fossa, or Meckelian foramen, or Meckelian canal) is an opening in the medial (inner) surface of the mandible (lower jaw) which exposes the Meckelian cartilage. Modern mammals (which includes placental
Placental mammals (infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished ... mammals) do not have a Me ...
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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] |
