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Keichousaurus BW
''Keichousaurus'' (key-cho-saurus) is a genus of marine reptile in the pachypleurosaur family which went extinct at the close of the Triassic in the Triassic-Jurassic extinction event. The name derives from Kweichow (now Guizhou Province) in China where the first fossil specimen was discovered in 1957. They are among the most common sauropterygian fossils recovered and are often found as nearly complete, articulated skeletons, making them popular among collectors. ''Keichousaurus'', and the pachypleurosaur family broadly, are sometimes classified within Nothosauroidea, but are otherwise listed as a separate, more primitive lineage within Sauropterygia. Description ''Keichousaurus'', like all sauropterygians, was highly adapted to the aquatic environment. Most specimens had small body, males sexually mature with snout-vent length (SVL), and in females by SVL. Mean SVL for mature males is approximately SVL, and for mature females, at most SVL. It had both long necks and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Triassic
The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a unit in chronostratigraphy. The Early Triassic is the oldest epoch of the Mesozoic Era. It is preceded by the Lopingian Epoch (late Permian, Paleozoic Era) and followed by the Middle Triassic Epoch. The Early Triassic is divided into the Induan and Olenekian ages. The Induan is subdivided into the Griesbachian and Dienerian subages and the Olenekian is subdivided into the Smithian and Spathian subages. The Lower Triassic series is coeval with the Scythian Stage, which is today not included in the official timescales but can be found in older literature. In Europe, most of the Lower Triassic is composed of Buntsandstein, a lithostratigraphic unit of continental red beds. The Early Triassic and partly also the Middle Triassic span the in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropterygian
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&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plesiosaurs
The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared in the latest Triassic Period, possibly in the Rhaetian stage, about 203 million years ago. They became especially common during the Jurassic Period, thriving until their disappearance due to the Cretaceous–Paleogene extinction event at the end of the Cretaceous Period, about 66 million years ago. They had a worldwide oceanic distribution, and some species at least partly inhabited freshwater environments. Plesiosaurs were among the first fossil reptiles discovered. In the beginning of the nineteenth century, scientists realised how distinctive their build was and they were named as a separate order in 1835. The first plesiosaurian genus, the eponymous ''Plesiosaurus'', was named in 1821. Since then, more than a hundred valid s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keichousaurus Fossil With Scale
''Keichousaurus'' (key-cho-saurus) is a genus of marine reptile in the pachypleurosaur family which went extinct at the close of the Triassic in the Triassic-Jurassic extinction event. The name derives from Kweichow (now Guizhou Province) in China where the first fossil specimen was discovered in 1957. They are among the most common sauropterygian fossils recovered and are often found as nearly complete, articulated skeletons, making them popular among collectors. ''Keichousaurus'', and the pachypleurosaur family broadly, are sometimes classified within Nothosauroidea, but are otherwise listed as a separate, more primitive lineage within Sauropterygia. Description ''Keichousaurus'', like all sauropterygians, was highly adapted to the aquatic environment. Most specimens had small body, males sexually mature with snout-vent length (SVL), and in females by SVL. Mean SVL for mature males is approximately SVL, and for mature females, at most SVL. It had both long necks and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allometric
Allometry is the study of the relationship of body size to shape, anatomy, physiology and finally behaviour, first outlined by Otto Snell in 1892, by D'Arcy Thompson in 1917 in ''On Growth and Form'' and by Julian Huxley in 1932. Overview Allometry is a well-known study, particularly in statistical shape analysis for its theoretical developments, as well as in biology for practical applications to the differential growth rates of the parts of a living organism's body. One application is in the study of various insect species (e.g., Hercules beetles), where a small change in overall body size can lead to an enormous and disproportionate increase in the dimensions of appendages such as legs, antennae, or horns The relationship between the two measured quantities is often expressed as a power law equation (Allometric equation) which expresses a remarkable scale symmetry: : y = kx^a \,\! or in a logarithmic form: : \log y = a \log x + \log k\,\! or similarly \ln y = a \ln x ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dactylosaurus
''Dactylosaurus'' is a genus of nothosaur in the family Pachypleurosauridae. Along with '' Anarosaurus'', ''Dactylosaurus'' was one of the earliest known pachypleurosaurs to come from Europe.Lepidosauromorpha: Pachypleurosauridae: Dactylosaurus & Anarosaurus Palaeos.com. Last accessed 2008-07-04. Etymology ''Dactylosaurus'' comes from the ' (), "" and ' (), meaning "" or ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hu Chengzhi
Hu Chengzhi (; 23 August 1917 – 12 April 2018) was a Chinese paleontologist and paleoanthropologist. He made the plaster casts of the Peking Man skull in the 1930s, and identified the Yuanmou Man (''Homo erectus yuanmouensis'') based on fossils collected by others. He discovered the first fossil of ''Keichousaurus'' in 1957, and this species, ''K. hui'', is named after him. A new hadrosaur discovered in Shandong is designated ''Shantungosaurus'' ''giganteus'' by Hu in 1973. Hu left school at 13 owing to poverty, and worked at Peking Union Medical College as Davidson Black's assistant. After Black died in 1934, Hu became an apprentice technician for fixing fossils at Franz Weidenreich's laboratory. He made cast copies of Peking Man's skull, and he was the last Chinese eyewitness of the Peking Man fossils, before they were lost during the Second Sino-Japanese War The Second Sino-Japanese War (1937–1945) or War of Resistance (Chinese term) was a military conflict that was p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guizhou
Guizhou (; formerly Kweichow) is a landlocked province in the southwest region of the People's Republic of China. Its capital and largest city is Guiyang, in the center of the province. Guizhou borders the autonomous region of Guangxi to the south, Yunnan to the west, Sichuan to the northwest, the municipality of Chongqing to the north, and Hunan to the east. The population of Guizhou stands at 38.5 million, ranking 18th among the provinces in China. The Dian Kingdom, which inhabited the present-day area of Guizhou, was annexed by the Han dynasty in 106 BC. Guizhou was formally made a province in 1413 during the Ming dynasty. After the overthrow of the Qing in 1911 and following the Chinese Civil War, the Chinese Communist Party took refuge in Guizhou during the Long March between 1934 and 1935. After the establishment of the People's Republic of China, Mao Zedong promoted the relocation of heavy industry into inland provinces such as Guizhou, to better protect them fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Keichousaurus Hui Sexual Dimorphism
''Keichousaurus'' (key-cho-saurus) is a genus of marine reptile in the pachypleurosaur family which went extinct at the close of the Triassic in the Triassic-Jurassic extinction event. The name derives from Kweichow (now Guizhou Province) in China where the first fossil specimen was discovered in 1957. They are among the most common sauropterygian fossils recovered and are often found as nearly complete, articulated skeletons, making them popular among collectors. ''Keichousaurus'', and the pachypleurosaur family broadly, are sometimes classified within Nothosauroidea, but are otherwise listed as a separate, more primitive lineage within Sauropterygia. Description ''Keichousaurus'', like all sauropterygians, was highly adapted to the aquatic environment. Most specimens had small body, males Sexual maturity, sexually mature with Snout–vent length, snout-vent length (SVL), and in females by SVL. Mean SVL for mature males is approximately SVL, and for mature females, at most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulna
The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of the forearm as the little finger. It runs parallel to the radius, the other long bone in the forearm. The ulna is usually slightly longer than the radius, but the radius is thicker. Therefore, the radius is considered to be the larger of the two. Structure The ulna is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. It is broader close to the elbow, and narrows as it approaches the wrist. Close to the elbow, the ulna has a bony process, the olecranon process, a hook-like structure that fits into the olecranon fossa of the humerus. This prevents hyperextension and forms a hinge joint with the trochlea of the humerus. There is ... [...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] |
Snout–vent Length
Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the most common measurement taken in herpetology, being used for all amphibians, lepidosaurs, and crocodilians (for turtles, carapace length (CL) and plastral length (PL) are used instead). The SVL differs depending on whether the animal is struggling or relaxed (if alive), or various other factors if it is a preserved specimen. For fossils, an osteological correlate Osteological correlates are marks on the bones of animals that are made from the causal interactions of the soft-tissue Soft tissue is all the tissue in the body that is not hardened by the processes of ossification or calcification such as bo ... such as precaudal length must be used. When combined with weight and body condition, SVL can help deduce age and sex. Advantages Bec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
