|
Keichousauridae
left, 220px, '' Pachypleurosaurus'' Pachypleurosauria is an extinct clade of primitive sauropterygian reptiles that vaguely resembled aquatic lizards, and were limited to the Triassic period. They were elongate animals, ranging in size from , with small heads, long necks, paddle-like limbs, and long, deep tails. The limb girdles are greatly reduced, so it is unlikely these animals could move about on land. The widely spaced peg-like teeth project at the front of the jaws, indicating that these animals fed on fish. In the species ''Prosantosaurus'', it was observed that they fed on small fishes and crustaceans which they devoured entirely and that its teeth regrew after they broke off. This was the first observation of tooth replacement in a European pachypleurosaur, the only other discovery of such an event was made in China. Classification Pachypleurosaurs were originally and are often still included within the Nothosauroidea (Carroll 1988, Benton 2004). In some more recent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wumengosaurus
''Wumengosaurus'' is an extinct aquatic reptile from the Middle Triassic (late Anisian stage) Guanling Formation of Guizhou, southwestern China. It was originally described as a basal eosauropterygian and usually is recovered as such by phylogenetic analyses, although one phylogeny has placed it as the sister taxon to Ichthyosauromorpha while refraining from a formal re-positioning. It was a relatively small reptile, measuring in total body length and weighing . In 2021, Qin ''et al''. described an additional specimen from Guizhou ( Panzhou District) as a new species of ''Wumengosaurus'', ''W. rotundicarpus''. Classification In the 2023 description of ''Luopingosaurus'', Xu ''et al''. recovered ''Wumengosaurus'' as a derived pachypleurosaurid, as the sister taxon to the clade formed by ''Luopingosaurus'' and ''Honghesaurus''. The results of their phylogenetic analyses are shown in the cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luopingosaurus
''Luopingosaurus'' (meaning "Luoping lizard") is an extinct genus of pachypleurosaurid sauropterygian from the Middle Triassic Guanling Formation of Yunnan Province, China. The genus contains a single species, ''L. imparilis'', known from a well-preserved, nearly complete skeleton. Discovery and naming The ''Luopingosaurus'' holotype specimen, IVPP V19049, was discovered in sediments of the Guanling Formation, dated to the Anisian age (Pelsonian substage) of the middle Triassic period, in Luoping County, Yunnan Province, China. This specimen consists of a nearly complete, ventrally-exposed, articulated individual, lacking only the end of the tail. The preserved portion of the skeleton measures long. In 2023, Xu ''et al''. described ''Luopingosaurus imparilis'', a new genus and species of pachypleurosaurid, based on these fossil remains. The generic name, "''Luopingosaurus''", combines a reference to the type locality in Luoping County with the Greek word "saurus", meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dianopachysaurus
''Dianopachysaurus'' is an extinct genus of pachypleurosaur known from the lower Middle Triassic (Anisian age) of Yunnan Province, southwestern China. It was found in the Middle Triassic Lagerstatte of the Guanling Formation. It was first named by Jun Liu, Olivier Rieppel, Da-Yong Jiang, Jonathan C. Aitchison, Ryosuke Motani, Qi-Yue Zhang, Chang-Yong Zhou and Yuan-Yuan Sun in 2011 and the type species is ''Dianopachysaurus dingi,'' thanking a Professor Ding for his help. ''Dianopachysaurus'' is most closely related to ''Keichousaurus'', another Chinese pachypleurosaur. Both belong to the family Keichousauridae. Pachypleurosaurs are hypothesized to have originated in the eastern Tethys Ocean (South China) before spreading and diversifying in the western Tethys in what is now Europe. A large ghost lineage of eastern pachypleurosaurs has long been inferred based on the phylogeny of the group. ''Dianopachysaurus'' represents an early stage in the radiation of pachypleurosaurs and it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Induan
The Induan is the first age of the Early Triassic epoch in the geologic timescale, or the lowest stage of the Lower Triassic series in chronostratigraphy. It spans the time between 251.902 Ma and Ma (million years ago). The Induan is sometimes divided into the Griesbachian and the Dienerian subages or substages. The Induan is preceded by the Changhsingian (latest Permian) and is followed by the Olenekian. The Induan is roughly coeval with the regional Feixianguanian Stage of China. Geology Stratigraphy The Triassic is the first period of the Mesozoic era. It is subdivided into the Lower, Middle, and Upper Triassic series, which are further subdivided into stages. The Induan is the first stage of the Lower Triassic, from 251.9 million to 251.2 million years ago, spanning the first 700,000 years after the Permian–Triassic extinction event. Stages can be defined globally or regionally. For global stratigraphic correlation, the International Commission on Stratigraphy (ICS) r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropterygia
Sauropterygia ("lizard flippers") is an extinct taxon of diverse, aquatic reptiles that developed from terrestrial ancestors soon after the end-Permian extinction and flourished during the Triassic before all except for the Plesiosauria became extinct at the end of that period. The plesiosaurs would continue to diversify until the end of the Mesozoic. Sauropterygians are united by a radical adaptation of their pectoral girdle, adapted to support powerful flipper strokes. Some later sauropterygians, such as the pliosaurs, developed a similar mechanism in their pelvis. Uniquely among reptiles, sauropterygians moved their tail vertically like modern cetaceans and sirenians. Origins and evolution The earliest sauropterygians appeared about 247 million years ago (Ma), at the start of the Middle Triassic: the first definite sauropterygian with exact stratigraphic datum lies within the Spathian division of the Olenekian era in South China. Early examples were small (around 60 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of archo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limb Girdles
Limb may refer to: Science and technology *Limb (anatomy), an appendage of a human or animal *Limb, a large or main branch of a tree *Limb, in astronomy, the curved edge of the apparent disk of a celestial body, e.g. lunar limb *Limb, in botany, the border or upper spreading part of a petal or sepal *Limb, in a measuring instrument, the graduated edge of a circle or arc Music * ''Limb'' (album), by Foetus, 2009 *''Limb'', an album by Justin Clayton, 1999 *"Limbs", a song by Emma Pollock from ''Watch the Fireworks'', 2007 *Limb Music, a German record label Other uses *Limb (surname), a list of people *Limb McKenry (1888–1956), American baseball pitcher *Limb Brook, a stream in Sheffield, South Yorkshire, England *Limbs Dance Company, in Auckland, New Zealand *Limbs, in archery, the upper and lower working parts of the bow; see recurve bow *Bresso Airfield, Bresso, Italy (ICAO code) *Limbu script (ISO 15924 code) See also * Limb darkening Limb darkening is an optical effect s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swissinfo
SWI swissinfo.ch is a multilingual news and information platform produced by the Swiss Broadcasting Corporation (SRG SSR). Its content is Swiss-centred, with top priority given to in-depth information on politics, the economy, the arts, science, education, and direct democracy. Switzerland's international political, economic and cultural relations are other key points of focus. The website is available in ten languages. History In the mid-1990s, economic circumstances forced swissinfo.ch to take a new strategic direction. The internet was advancing fast, heralding a new era for the producing journalists and the Swiss Radio International (SRI) audience alike. The German, French, English and Portuguese sites went online in 1999. The Italian, Japanese and Spanish sites followed in 2000, with Arabic going live on 1 February 2001 and Chinese in September of the same year. Within just two years, the internet platform for expatriate Swiss was already better known than SRI's short-wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpianosaurus
''Serpianosaurus'' is an extinct genus of pachypleurosaurs known from the Middle Triassic (late Anisian and early Ladinian stages) deposits of Switzerland and Germany. It was a small reptile, with the type specimen of ''S. mirigiolensis'' measuring long. Fossils of the type species, '' S. mirigolensis'', have been found from the middle Grenzbitumenzone, the oldest strata of Monte San Giorgio, Switzerland, an area well known for its abundant pachypleurosaur remains. The locality dates back to sometime around the Anisian/Ladinian boundary of the Middle Triassic, around 242 Ma, with ''Serpianosaurus'' most likely occurring strictly during the latest Anisian. This makes it the one of the oldest sauropterygians from Monte San Giorgio, with only the rare pachypleurosaur ''Odoiporosaurus'' being older. Certain aspects of its morphology also suggest it is one of the most basal forms. Cajus G. Diedrich in 2013 described and named a second species, ''S. germanicus'', based on a postcra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladistics
Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived characteristics ( synapomorphies'')'' that are not present in more distant groups and ancestors. However, from an empirical perspective, common ancestors are inferences based on a cladistic hypothesis of relationships of taxa whose character states can be observed. Theoretically, a last common ancestor and all its descendants constitute a (minimal) clade. Importantly, all descendants stay in their overarching ancestral clade. For example, if the terms ''worms'' or ''fishes'' were used within a ''strict'' cladistic framework, these terms would include humans. Many of these terms are normally used paraphyletically, outside of cladistics, e.g. as a 'grade', which are fruitless to precisely delineate, especially when including extinct species. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
